the united republic of tanzania - gcla bat-bep training report... · 2014-09-18 · the united...
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The United Republic of Tanzania
April 2009
Pilot Project: Sound Management of Chemicals
TRAINING AND PROMOTION OF BEST AVAILABLE TECHNIQUES (BATS) AND BEST ENVIRONMENTAL PRACTICES
(BEPS) APPLICATIONS AND
TRAINING OF TECHNICAL PERSONNEL IN CHEMICALS MANAGEMENT WHO WILL SERVE AS TRAINERS AT THEIR
WORKPLACE
Tanzania SAICM Pilot Project
The 2006-2009 pilot project in support of National SAICM implementation to
“Strengthen Governance, Civil Society Participation and Partnerships within
an Integrated National Chemicals and Waste Management Programme” in
Tanzania has been supported by the United Nations Institute for Training and
Research (UNITAR) with the financial support of the Swiss Agency for
Development and Cooperation.
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Chapter 1: Introduction Chemicals have become an indispensable part of our life, sustaining many of our activities, preventing and controlling diseases, and increasing agriculture productivity. However, one cannot ignore that chemicals may also damage human health and poison the environment. The nature, variety and quantity of chemicals used in countries vary widely according to factors such as the country’s economy, and the structure of its industrial and agricultural sectors. More than 43 millions of chemical substances are used on a global scale. Chemicals have contributed to the improvement of living conditions, and there is no denying that they yield benefits without which modern society could not do (e.g. in the production of food and pharmaceuticals). Tanzania is implementing a five year multi-stakeholder project called Pilot Project: Sound Management of Chemicals. The project is implemented under partnership of different stakeholders from government agencies and institutions, research institutions, private sector and civil society organizations. Under the umbrella of the Pilot Project: Sound Management of Chemicals, AGENDA for Environment and Responsible Development (AGENDA) in collaboration with Chemical Risk Expert Foundation of Tanzania (CREFT) had implemented two partrnership projects namely “Training and Promotion of Best Available Techniques (BATs) and Best Environmental Practices (BEPs) Applications and Training of Technical Personnel in Chemicals Management who will serve as trainers at their workplace in four zones of Lake, eastern, northern and southern highlands in mainland Tanzania. These two projects had been implemented (in parallel due to financial limitations) between January and April 2009.
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Chapter 2: Literature Review
Literature review covered relevant available literature in both print and/or electronic form. The documentary review was carried out to identify the Best Environmental Practices and Best Available Techniques in chemicals management. Further, it involved review of Multilateral Environmental Agreements as well as national policies, legislation and Acts. Furthermore, the review also identified potential stakeholders for the training such as government agencies and institutions, research institutions, private sector and civil society organizations.
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Chapter 3: Methodology
This section covers the methodology used in conducting the trainings. It explains what the training entailed and methods used, training execution plan and includes the names and affiliation of stakeholders trained. Identification of Potential Trainees Identification of the institutions that will provide trainees for the training was conducted basing on the roles and responsibilities of the institutions with relevance to chemicals management in work places throughout mainland Tanzania. This was done in consultation with SAICM pilot project focal point i.e. Government Chemist Laboratory Agency. Training Manual Training manuals were developed, printed and distributed to each participant (see attached Training Manual) during the training. Training Conduction Training and Promotion of Best Available Techniques (BATs) and Best Environmental Practices (BEPs) applications and Training of Technical Personnel in Chemicals Management who will serve as trainers at their workplace in four zones of Lake, eastern, northern and southern highlands in mainland Tanzania. Participants were drawn from government agencies and institutions, research institutions, private sector and civil society organizations. The two projects were implemented in parallel due to the fact that the objective/target was to cover more stakeholders while the funds allocated could not allow for the two projects to be implemented separately and covers the target numbers.
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Chapter 4: Results and Discussion 4.1. Results of the Training In implementation of the project, two trainings were conducted on 25th March and 2nd April 2009 at Mbezi Garden Hotel in Dar es salaam and Vocational Training Course and Conference Centre in Mwanza respectively. The Dar es salaam training drew participants from Eastern, Northern and southern highlands zones while the Mwanza training drew participants from lake zone. Training organizers extended invitation to 83 participants from all regions of mainland Tanzania. 70 percent of the invited participants were from the government institutions while 30 percent was extended to public interest groups. 4.1.1. Dar es Salaam Training Invitation for the Dar es Salaam training was extended to 57 participants from Dar es Salaam, Morogoro, Coast, Lindi, Mtwara, Tanga, Dodoma , Arusha, Kilimanjaro, Manyara, Mbeya, Ruvuma , Rukwa and Iringa. Participants that attended the training were 31 (see attached list of Dar es Salaam Training participants list). 4.1.2. Mwanza Training Invitation for the Dar es Salaam training was extended to 57 participants from Singida, Tabora, Shinyanga, Kigoma, Mwanza, Mara and Kagera. Participants that attended the training were 26 (see attached list of Mwanza Training participants list). 4.2. Discussions of the Trainings During the workshop, participants wanted to know who is responsible to manage importation of chemicals while most of them are not having important information labels and the response was that the government through its organs. All imported chemicals should either follow TPRI for agricultural products and GCLA for Industrial and Consumers chemicals. Legislations requires all chemical containers to have labels that must be printed with language that is readable and understandable to users as well as include important safety phrases and symbols to help the users know better ways of use and application of the chemical contained. In order to achieve higher chemicals management, the government was advised to borrow leaf from REACH guide developed in Europe due to the fact that about 99% of chemicals in the world have not been done risk assessment. By putting liability of conducting risk assessment to producers will help improve the situation. Furthermore, it was argued that the government is responsible for protecting its people and makes them aware of the chemicals effects. Participants wanted to know for what reason that, there are good laws in the country but their enforcement is poor and what should be done to improve the situation due to the fact distributors have less information about such chemicals as well as consumers don’t use protective gears also do not use proper spraying regimes. The response was that enforcement is just one part but public education is a major tool to
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rely on. Therefore government and other stakeholders were urged to increase provision of public education on chemical use and safety as such large part of the public is ignorant on chemical issues. It was commented that, change of attitude of large part of the public is vital due to the fact that most chemical consumers do not use protective gears on handling chemicals they everyday such as the case of small scale miners with mercury use. The use of protective gears should be included in laws and enforced in order to facilitate sound chemicals management. There was a queried that chemicals have labels and so on, so does it mean such information given has been scientifically proven? If yes, then risk assessment has been done? The response was that information given on labels is just normal information but the information from risk assessment gives details of how many people are likely to be infected etc. Then it was asked to what extent are these chemicals used in suicide cases and the response was that cases of poisoning are so many but to what extent are not clear, these chemicals are also used as weapons and for more information can be obtained from GCLA. There is high illegal cross border trading of agrochemicals in southern coast of Tanzania. Some expired chemicals were also sold to consumers but the expiry date hidden or relabeled, people complained but they were convinced the chemicals were safe. Participants asked for opinion of the facilitators on the issue raised and the response was that those are total breach of the law for example deleting or illegal re-labeling of the expiry dates etc. Extension services should be there and well provided and not just promoting the chemicals as is the case now on promoting agriculture without due consideration of other important factors. Hence, education and awareness raising should be done because people are at a very high risk in the current situation. It was discussed that most problems that lead to improper use of chemicals are caused by unavailability of funds and improper allocation of resources, hence less awareness education is passed to communities. Furthermore, some policies implementations contribute to improper use of chemicals as well as encouragement of entrepreneurship particularly on agrochemical business which lead hazardous chemicals to be sold without proper guidelines and instructions with unprofessional people who focus more on profit. Further, some experts are engaging in the politics which tend to make them become less concerned with serious issues about the proper use of chemicals. In case of misuse of chemicals, it was advised to report to custodian of registry, to make follow up on the issue so that they can do an investigation on the incident. Some participants were concerned about unavailability of the legislation to govern open smocking of cigarettes which affects more than the smoker and the response was that due to our underdevelopment situation, our economy depends much on revenues from the business hence it becomes difficult to hamper the businesses conduction such as of cigarettes but with time we will be able to afford to enact such kind of laws.
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It was further, queried if we have capacities to do the researches (government or private sector) on substitution and alternatives which was responded that some institutions can do the research and there are other places where substitution is being in employed. In collaboration with these we can use those substitutes and do researches to fill the gaps. Information on alternatives to hazardous chemicals that are used by the communities are not readily available, hence participants urged the government and other stakeholders to step up gear on awareness on the same. There was a concern that emergency response is not up to standard and requirement on transportation of consignment of highly hazardous chemicals such as Sodium Cyanide. Furthermore, community awareness enhancement is not adequate and areas where such chemicals passes. More concern was on the attitude of community to run and rooting products in accidents scenes such that it will be a big disaster with the current state of affair when there happens an accident involving a truck with consignment of sodium cyanide (have similar white crystals like sugar). The government was urged to step up more precautions and protection as well as greater enforcement of its legislations on chemicals management. There were comments for that the government should take up serious measures on protecting its people from chemicals problems. This has been raised due to concerns raised by communities in Namtumbo district, Ruvuma on the impacts that may emanate from Uranium mining activities done in the area. Furthermore, most protective gears for chemicals are very hard to find though inputs are found and sold easily. In addition to that, participants urged for more efforts to be done on chemical issues and awareness by starting on translating the training manual into Kiswahili so as to be easily used by most Tanzanians as well as large mass production in order to reach more people dealing with chemicals. Moreover, poverty had been driving people to use hazardous chemicals without protective gears due to the fact that they can not afford safer alternatives and protective gears. There was a comment that there are data for chemicals that enter the country legally but for chemicals which enter illegally there are no such data and this brings a lot of problems in monitoring them, knowing their effects and about their proper disposal. Implementation of consumer and industrial chemicals has started about three years ago and so to put all chemicals into database may take long, but have shown some encouraging signs on its implementation. There was also a concern that schools and learning institutions laboratories uses a lot of chemicals hence more awareness enhancement need to be conducted on proper management of chemicals and their use in education sector. Likewise, a concern was raised on chemical pollution on streams caused by car/vehicle washing in turban areas which could be tackled by local government officers who issues them business licenses but hindered by the regulators focusing on revenue collection. It was asked if milk is the general antidote for the people that are prone to chemical exposure and the response was that not all chemicals have antidote. First aid is to used grounded charcoal and send casualties to hospital for further treatment.
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There was a concern that most municipalities tend to designate a dumpsite which include all types of wastes while there is a growing tendency of children scavenging on the dumpsites which poses health and environmental hazards to scavengers and nearby communities. It was urged that the government to start introducing sanitary landfills in order to manage wastes from hospitals and other types of waste for proper management to minimize health and environmental hazards. It was commented that policy needs to be influenced in harmonized way and this could be done by starting engaging in it. Different approaches can be used in order to achieve this objective but it will take time. Policy makers do not know everything hence there is a need to conduct awareness to all levels in order chemical to be taken into consideration in government plans. There is a need to use different advocacy skills on influencing government decisions. We can exploit available cheap media opportunities for awareness raising activities (e.g. StarTV through Jarida Mridhawa Program).
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Chapter 5: Conclusions and Recommendations 5.1. Conclusions From the experiences of conducting the training, it can be concluded as follows:
• Most of the technical staff that handles and uses chemicals do not know the safety issues and needs for the use of protective gears;
• Most chemicals are used without following use guidelines and hence poses threat to bystanders;
• There is the need to conduct awareness on chemical issue to policy makers for chemical consideration to be included in government plans;
• There is high misuse of chemicals and illegal chemicals trading with poor enforcement of the available legislations;
5.2. Recommendations It can be recommended as follows:
• Awareness enhancement on chemicals management and use to the public is vital in order to minimise health and environmental hazards from chemicals;
• More training on chemicals safety should be extended to policy makers for effective mainstreaming chemical issues in government plans and new policies as well as consideration in government plans;
• There is great need for translating the training manual into Kiswahili language as well as mass production for easy access and utilisation by most extension officers and general public in Tanzanians.
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Annexes
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Annex 1: Training Participants
TANZANIA SAICM PILOT PROJECT TRAINING AND PROMOTION OF BAT/BEP APPLICATION ON CHEMICALS
MANAGEMENT IN WORKPLACES MBEZI GAREN HOTEL 25TH APRIL, 2009
1 Fransis M. Tindwa RAIA Box 1145, Songea. 0784 - 837604 [email protected] 2 Paul M. Kugopya MDC Box 85, Mafia 0753 - 989866 [email protected]
3 Rashid Champuma KIMWAM Box 888, Mtwara 0784 - 450413 [email protected] 4 Vony Bright Madini Box 81, Chunya 0782 - 824260 - 5 Phinius Kasasi Kilimo Box 400, Babati 0784 - 589268 -
6 Christian B. Ngorozi Kilimo DSM Box 7, Bagamoyo 0763 -326060 christopher 7 Mwadhini O. Myanza IRTECO Box 6820, Moshi 0754 - 583242 [email protected] 8 Ozem Chapita KAESO Box
294,Sumbawanga 0786 208237 [email protected]
9 Hamisi A Mashauri Kilimo – Lindi Box 328 Lindi 0754 770685 [email protected] 10 Joseph Riziki ENVIROCARE DSM Box 942 UDSM 0752 897411 11 Sammy Mwakyusa DED – Namtumbo Box 55 Namtumbo 0715 201787 12 Mkirya Joseph LCWF LIWALE Box 78 Liwale 0717 011295 [email protected] 13 Manfred Bitala HORT –TENGERU Box 1255 Arusha 0783 502870 [email protected] 14 Maund N. Safe CITY COUNCIL – TANGA Box 178 Tanga 0784 588742 [email protected] 15 Joseph B.G Kiyungu KILIMO Box 27 Mpwapwa 0784 393784
16 Atimamu Abdallah MBEYA CEMENT Box 529 Mbeya 0754 895836 [email protected] 17 Tina Mwasha TANZANIA CHAMBER OF
MINERAL & ENERGY Box 13369 DSM 0754 035625 [email protected]
18 Salasius S. Mutalemwa MADINI Box 327 Songea 0755 548722 [email protected] 19 Jaffer K. Mwakibete TWIGA CHEMICAL Box 20786 DSM 0734 379162 [email protected] 20 Lesian Mollel VIJANA VISION TANZANIA Box 28007 Kisarawe
DSM 0714 474023 [email protected]
21 Mosha G. K MUFINDI ENVIRONMENT Box 215 Mafinga 0784 772213 [email protected]
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TRUST 22 B.N. Mliga MUFINDI WOOD PLANT Box 215 Mafinga 026 2772217 [email protected] 23 J. Losai JET Box 9191 DSM 0713 357713 [email protected]
24 Aziza Swedi MINISTRY OF ENERGY & MINERALS
Box 2000 DSM 0755 731070
25 Frida Godwin TAEEs Box 35454 DSM 0713 599301 [email protected] 26 Prof. JHK Katima AGENDA Box 77266 DSM 0787 717102 [email protected] 27 Haki Rehani AGENDA Box 77266 DSM 0754373129 [email protected] 28 Cecilia Mwakasege AGENDA Box 77266 DSM 0713 197789 [email protected] 29 Anita Rugaika AGENDA Box 77266 DSM 0713 630767
30 Bunga Abdallah AGENDA Box 77266 DSM 0784 309431 [email protected]
31 Nadhifa Ramadhan AGENDA Box 77266 DSM 0713 359003 [email protected]
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TANZANIA SAICM PILOT PROJECT TRAINING AND PROMOTION OF BAT/BEP APPLICATION ON CHEMICALS
MANAGEMENT IN WORKPLACES VETACONFERENCE – MWANZA, 2ND APRIL, 2009
S/NO
NAME ORGANIZATION ADDRESS TELEPHONE E-MAIL
1 Dr. Thomas J. Assey Musoma District Council Box 921 Musoma 028 2620528 [email protected] 2 Mangi C. Makolobela Ministry of Energy and
Minerals Zonal Office Shinyanga
Box 834 Shinyanga 0784 780424 028 2763282
3 Sophareth M. Maotola Zonal Office – Singida (MEM)
Box 925 Sungida 0755 521828
4 Emmanuel Mahona Kilimo/Mifugo (W) Box 3 Nzega 0755 776366 5 Lucas Wambura LANESO Box 10016 Mwanza 0784 366866 [email protected] 6 Dr. Enock Masanja UDSM Box 35131 DSM 0784 787578 [email protected] 7 Prof. JHY Katima UDSM Box 35131 DSM 0787 717102 [email protected] 8 Ahmad Kassim LITAMO Mwanza Box 2746 MZA 0756 36408 9 P. Mtango GCLA Mwanza Box 502 MZA 0754 882864 [email protected]
10 Golden Hainga Small Scale Miner - Geita Box 26 Geita 0784 684499 [email protected]
11 Eliamini I. Mkenga GCLA – Mwanza Box 502 MZA 0754 276066 [email protected] 12 Rukia Mgumia Tabora NGO’s Cluster Box 113 Tabora 0737 018384 [email protected] 13 Philip P. Ngereja Madini Tabora Box 1345 Tabora 0754 263524 [email protected] 14 Benedict W. Kwangu LANESO Box 10016 MZA 0713 242522 [email protected] 15 Tibezuka Fundisha Foundation One World
Mwanza Box 10546 MZA 0784 481864 [email protected]
16 Yusto P. Muchuruza KADETFU Box 466 Bukoba 0754 740267 [email protected] 17 Charles E. Mpambwe VETA Mwanza Box 1983 MZA 0787 451110 [email protected] 18 Avelinius Rwegasira Foundation Help - Musoma Box 854 Musoma 0787 945414 [email protected] 19 Jackson Kahabi Kilimo/Mifugo – Kigoma MC Box 44 Kigoma 0762 935248 20 Tabitha B. Luwanja VETA Mwanza Box 1983MZA 0755 036768 [email protected]
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21 Adam Ndokgi VEFDA - Misungwi Box 2516 0755 877666 [email protected] 22 Paul S. Rwegasira SHIKUKUMAJA Mwanza Box 11518 MZA 0787 288323
0752 808876 [email protected]
23 Kassian G. Kimela ELI Tanzania – Magu-Mwanza
Box 11559 0754 597721 [email protected]
24 Haji Rehani AGENDA Box 77266 DSM 0754373129/ 0715 373129
25 Anita Rugaika AGENDA Box 77266 DSM 0713 630767 [email protected] 26 Bunga Abdallah AGENDA Box 77266 DSM 0784 309431 [email protected]
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Annex 2: Photographs of the Trainings
AGENDA chairman professor Jamidu Katima, third from left in front raw together with participants of Dar es Salaam Training.
Participants engaged in questions and answers during Dar es Salaam Training
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Prof. Jamidu Katima stressing issues during Dar es Salaam Training
Participants and facilitator discussing during Dar es salaam Training
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AGENDA chairman prof.Jamidu katima 2nd from left together with CREFT Chairman Dr.Enock Masanja 3rd from right in front raw with participants in
Mwanza Training.
Prof. Jamidu Katima delivering presentation during Mwanza Training.
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Dr. Enock Masanja elaborating an issue during the training
Cross section of the Training venue during one of Mwanza Training sessions
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Annex 3: Training Manual
The United Republic of Tanzania
March 2009
Pilot Project: Sound Management of Chemicals
TRAINING AND PROMOTION OF BEST AVAILABLE TECHNIQUES (BATS) AND BEST ENVIRONMENTAL PRACTICES
(BEPS) APPLICATIONS AND
TRAINING OF TECHNICAL PERSONNEL IN CHEMICALS MANAGEMENT WHO WILL SERVE AS TRAINERS AT THEIR
WORKPLACE
Training Manual
Tanzania SAICM Pilot Project
The 2006-2009 pilot project in support of National SAICM implementation to
“Strengthen Governance, Civil Society Participation and Partnerships within
an Integrated National Chemicals and Waste Management Programme” in
Tanzania has been supported by the United Nations Institute for Training and
Research (UNITAR) with the financial support of the Swiss Agency for
Development and Cooperation.
1
Table of Contents Table of Contents....................................................................................................................................................................... 1 1. INTRODUCTION ............................................................................................................................................................. 3
1.1 SOUND MANAGEMENT OF CHEMICALS: THE BASICS ............................................................... 3 2. INTRODUCTION TO CHEMICALS MANAGEMENT ...................................................................................................... 5
2.1 WHAT DO WE KNOW ABOUT CHEMICALS? ............................................................................. 5
2.1.1 Getting to Know Basic Chemistry ........................................................................................ 5
2.1.2 Name, Surname and “Nickname” af Chemicals: How Do We Refer To Them? .................................. 6
2.1.3 What Do Chemicals Look Like? ......................................................................................... 6
2.2 PAINFUL, DEADLY ENCOUNTERS WITH POISONS .................................................................. 14
2.2.1 Workers and Hazardous Substances: A Perilous Relationship ................................................... 14
2.2.2 Environment and Hazardous Substances: More than Just a Difficult Relationship ............................ 16
2.3 PREVENTION, THE BEST ANTIDOTE TO CHEMICAL EXPOSURE ................................................ 19
2.3.1 Assessing Hazards, Risks and Safety: Safer Handling, What Else? ............................................. 19
2.3.2 Precautionary Principle ................................................................................................. 21
2.3.3 Alternatives: Substitution Principle .................................................................................... 21
2.4 GREEENING OUR CHEMICAL WORLD ................................................................................. 21
2.4.1 What are the Limits of the Current Chemistry? ...................................................................... 21
2.4.2 Green Chemistry is the Key! Can the Door Be Unlocked?......................................................... 22 3. SAFE USE OF CHEMICALS IN THE WORKPLACE .................................................................................................... 24
3.1 PREVENTION IS THE CORNERSTONE: ENHANCING A SAFETY AND PREVENTION CULTURE ........... 24
3.1.1 Preparing a Framework for “Intervention” ............................................................................ 25
3.1.2 Where to Get Information? ............................................................................................. 26
3.2 BEING A WORKPLACE DETECTIVE: IDENTIFICATION OF EXPOSURE RISKS AND CHEMICALS ......... 29
3.2.1 Identification of “Hot Spots”: Where are the Problems and Risks? ............................................... 30
3.2.2 Mapping Out the Hazardous Substances and Materials ........................................................... 31
3.2.3 Identification of Exposure Characteristics ............................................................................ 31
3.3 IS YOUR JOB PUTTING YOU AT RISK? QUALITATIVE RISK ASSESSMENT .................................... 33
3.4 GET PRIORITIES RIGHT! PLAN OF INTERVENTION ................................................................. 34
3.4.1 Controlling the Hazard: Principles for Operational Control ......................................................... 35
3.4.2 Control Measures For The Storage, Disposal, Waste And Treatment ........................................... 37
3.4.3 Control Measures for the Transport of Chemicals .................................................................. 39
3.5 SAFE CHEMICALS – SAFE PRODUCTS GUIDELINES TO ENFORCE THE “SUBSTITUTION PRINCIPLE” 40
3.5.1 Identification of the Problem ............................................................................................ 41
3.5.2 Information about Processes and Substances ...................................................................... 41
3.5.3 Establishment of Substitution Criteria ................................................................................. 42
3.5.4 Research/Studies and the Evaluation of Alternatives .............................................................. 43
3.5.5 Pilot Experience .......................................................................................................... 43
3.5.6 Implementation of the Substitution .................................................................................... 44
3.5.7 Revision and Risk Evaluation .......................................................................................... 44 3.6 KEEP AN EYE ON WHAT IS HAPPENING! HEALTH AND ENVIRONMENTAL SURVEILLANCE AND
FOLLOW-UP .................................................................................................................. 44
3.6.1 Surveillance and Follow-Up: Evaluation, Efficiency and Revision ................................................ 44
3.7 WATCH OUT! RISK NEVER SLEEPS: EMERGENCY AND FIRST-AID PROCEDURES ......................... 44
3.7.1 The Emergency Plan .................................................................................................... 45 4. INTRODUCTION to BAT/BEP ....................................................................................................................................... 46
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4.1 DEFINITIONS ................................................................................................................. 46
4.2 CONSIDERATION OF ALTERNATIVES IN THE APPLICATION OF BEST AVAILABLE TECHNIQUES ....... 47
4.2.1 An Approach to Consideration of Alternatives ....................................................................... 47
4.2.2 Other Important Considerations ....................................................................................... 48 4.2.3 Best Available Techniques And Best Environmental Practices: Guidance, Principles And Cross-Cutting
Considerations .......................................................................................................... 48
4.2.4 Chemicals listed in Annex C: Formation mechanisms .............................................................. 50
4.3 WASTE MANAGEMENT CONSIDERATIONS ........................................................................... 51
4.3.1 Introduction ............................................................................................................... 51
4.3.2 Definitions ................................................................................................................. 51
4.3.3 The Importance of Developing National Waste Management Strategies ........................................ 53
4.3.4 Some Principles to be Applied ......................................................................................... 53
4.3.5 The Importance of Public Education .................................................................................. 53
4.3.6 Influencing Production and Products .................................................................................. 53
4.3.7 Product Warranties ...................................................................................................... 54
4.3.8 Encourage Companies to Use Environmental Management Systems ........................................... 54
4.3.9 Producer Responsibility ................................................................................................. 54
4.4 SOURCE REDUCTION AS A PRIORITY ................................................................................. 54
4.4.1 Collection.................................................................................................................. 54
4.4.2 Recycling .................................................................................................................. 55
4.4.3 Final Disposal ............................................................................................................ 55
4.4.4 Landfill ..................................................................................................................... 55
4.4.5 Incineration ............................................................................................................... 56
4.5 CO-BENEFITS OF BEST AVAILABLE TECHNIQUES FOR CHEMICALS LISTED IN ANNEX C................ 56
4.5.1 General Considerations ................................................................................................. 56
4.5.2 Information, Awareness and Training ................................................................................. 57
4.5.3 Flue Gas Cleaning Processes ......................................................................................... 57 4.6 WASTEWATER TREATMENT PROCESSES ..................................................................................................... 57 4.7 MANAGEMENT OF FLUE GAS AND OTHER RESIDUES ................................................................................. 58
4.7.1 Flue Gas Treatment Techniques (Air Pollution Control Devices) ................................................. 58
4.7.2 Comparison Of PCDD/PCDF Control Techniques .................................................................. 58
4.7.3 Rapid Quenching Systems ............................................................................................. 59
4.7.4 Afterburners .............................................................................................................. 59
4.7.5 Dust Separation .......................................................................................................... 59
4.7.6 Scrubbing Processes .................................................................................................... 61
4.7.7 Sorption Processes ...................................................................................................... 62
4.7.8 Catalytic Oxidation of PCDD/PCDF ................................................................................... 63
4.7.9 Treatment of Flue Gas Treatment Residues ......................................................................... 63
4.7.10 Thermal Treatment of Flue Gas Treatment Residues .............................................................. 65
4.7.11 Treatment of Spent Dry Adsorption Resins .......................................................................... 65
4.7.12 Treatment of Wastewaters ............................................................................................. 65
4.8 TRAINING OF DECISION MAKERS AND TECHNICAL PERSONNEL .............................................. 66
4.9 TESTING, MONITORING AND REPORTING ............................................................................ 66
4.9.1 Testing and Monitoring .................................................................................................. 66
4.9.2 Sampling and Analysis of PCDD/PCDF and Dioxin-like PCB ..................................................... 66
4.9.3 Limit of Detection and Limit of Quantification ........................................................................ 67
4.9.4 Gas Reference Conditions ............................................................................................. 68
4.9.5 Bioassay Methods ....................................................................................................... 68
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1. INTRODUCTION
1.1 SOUND MANAGEMENT OF CHEMICALS: THE BASICS Chemicals have become an indispensable part of our life, sustaining many of our activities, preventing and controlling diseases, and increasing agriculture productivity. Synthetic chemicals used in farms help feed us. Chemicals provide synthetic fibbers for clothing and molecules to manufacture medicines. They provide the basic materials to the manufacturing of cars, phones and computers, as well as many building materials, rugs and other furnishings. The benefits are immense. However, one cannot ignore that chemicals may also damage human health and poison the environment. The nature, variety and quantity of chemicals used in countries vary widely according to factors such as the country’s economy, and the structure of its industrial and agricultural sectors. More than 43 millions of chemical substances are used on a global scale.1 Production of chemical substances worldwide is set to rise from one million tonnes in 1930 to 400 million tonnes nowadays.2 Chemicals have contributed to the improvement of living conditions, and there is no denying that they yield benefits without which modern society could not do (e.g. in the production of food and pharmaceuticals). The global chemical industry also contributes to economic prosperity in terms oftrade and jobs. Its annual sales are estimated at more than US$1,600 billion. The industry employs over 10 million people worldwide.3 However, chemicals can also cause irreversible damage to human health and the environment since many have potentially toxic effects. Exposure risk arises during production, storage, handling, transport, use and disposal of chemicals, as well as from accidental leakage or illegal dumping. Thus, the whole life cycle of a chemical substance needs to be considered when assessing its dangers and benefits. In particular, both the manufacture and use of chemicals takes a heavy toll on workers. Millions of them are exposed to chemicals (occupational exposure) on a daily basis, not only in the chemical industry but in sectors where they are used, including agriculture, the building and construction sector, the woodworking industry, automobile, textile and electronics manufacturing.4
Chemical hazards are currently a major cause of occupational mortality in the world. According to the International Labour Organization (ILO), hazardous substances kill about 438,000 workers annually, and 10% of all skin cancers are estimated to be attributable to workplace exposure to hazardous substances.5 Additionally, the World Health Organization indicates that approximately 125 million workers worldwide are exposed to asbestos in the workplace, which results in at least 90,000 deaths every year; the figure is rising annually.6
1 CAS Database Registry: http://www.cas.org/expertise/cascontent/registry/regsys.html (last accessed 14 April 2008) 2 Copenhagen Chemicals Charter, Chemicals Under The Spotlight, International conference, 27-28
October 2000, Copenhagen http://www.eeb.org/publication/2000/CCC_from_BEUC_corrected_EL_clean.pdf (last accessed 14 April 2008) 3 International Council of Chemical Associations (ICCA) www.icca-chem.org (last accessed 19
December 2007) 4 Including the disassembly of mobile telephones, computers and other electronic equipment, which
are often sent from industrialized to developing countries for this purpose. Shipbreaking is another example of the transfer of disassembly to developing countries (e.g. India), with potentially lethal consequences for the health of those engaged in this type of work. www.ilo.org/public/english/protection/safework/wdcongrs /intrep.pdf (last accessed 19 December 2007) 5 International Labour Organization. ILO (2005). “Facts on Safety at Work”
http://www.ilo.org/wcmsp5/groups/public/---dgreports/--- dcomm/documents/publication/wcms_067574.pdf, (last accessed 14 April 2008) 6 “Asbestos Exposure Responsible for 90,000 Deaths Annually”. Asbestos News http://www.asbestosnews.com/news/asbesos-deaths-annually.html, (last accessed 14 April 2008)
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The ILO further estimates that there are around 270 million occupational accidents and 160 million work-related diseases each year among a global workforce of 2.8 billion people.7 However, no data are available so far on the percentage of occupational diseases related to chemicals exposure at global level. The worker handling chemicals is not the only one at risk. Individuals may also be exposed to chemical risks at home. The environment as well is affected, as chemicals may pollute the air we breathe, the water we drink, and the food we eat. They may have reached forests and lakes, destroying wildlife and altering the ecosystems. As a result of economic activity, many chemicals are released into the environment. They are not only generated by the chemical industry (quantitatively, power generation, and metals and mining industries are larger sources of pollution), but also by other sectors, for example agriculture, car manufacturing, construction, energy production, extraction of fossil resources and minerals, metallurgy, pharmaceuticals, textile or transport, among others. The environment has been at the receiving end of a wide range of hazardous substances, which has caused unprecedented environmental degradation. The challenge has now to be addressed as it is a struggle for the future of the planet, an issue of survival for other species and quality of life for humans. One of the root causes of environmental degradation by chemical substances is the lack of knowledge about the inherent hazardous properties of most chemicals found on the market and their sound and safe use. It is an appalling fact that over 99 per cent of the total volume of marketed substances has never undergone in-depth assessment of their risks to human health and the environment.8 The direct consequence of this lack of data is that many hazardous chemicals are not classified as such, and are therefore sold without appropriate labels or safety data sheets. Thus, many chemicals are used in the workplace while their potential effects on the health of workers exposed to them and on the environment are barely known, or known too late. Chemical risks at work derive both from the intrinsic hazardous properties of chemicals and from workers’ levels of exposure to these substances, reflecting the way in which they are used in the workplace. When it comes to safe use of chemicals at work, the situation varies according to countries, sectors of activity and company size. In general, the situation in developing countries, is such that often chemicals are used at industrial and agricultural sites with highly toxic active ingredients, which, although they may have been banned in industrialized countries, are still marketed in the developing world. Protective equipment is often not available, and information and training are mostly lacking. Due to less stringent regulations and, as a consequence, deliberate corporate strategies to relocate production to countries with lower standards, workers in these countries are increasingly becoming victims of social, environmental, and health and safety dumping. The growth of chemical industries, both in developing and developed countries, is set to go on increasing this 21st century. The environmentally sound management of toxic chemicals requires proper management of chemicals from manufacture to disposal (often referred to as cradle-to-grave or life-cycle management). This means developing a chemistry as little harmful as possible, based on the application of a series of principles that help reduce or eliminate the generation of hazardous substances in the design, manufacturing and use of chemicals:9 for example, using renewable raw materials, manufacturing non-toxic and biodegradable products, and avoiding waste. Clean production and green/sustainable chemistry need to be factored in the discussion as they pave the way to sustainability. These are new concepts that have to gain importance in research, negotiation, and the production process if sustainable development is to be attained. Basic elements for sound and sustainable management of chemicals are:10
a) adequate legislation; b) information gathering and dissemination; c) capacity for risk assessment and interpretation;
7 International Labour Organization. ILO. 2005. “Facts on Safety at Work”
http://www.ilo.org/wcmsp5/groups/public/---dgreports/--- dcomm/documents/publication/wcms_067574.pdf 8 European Commission (February 2001). “Strategy for a future Chemicals Policy”. White Paper.
COM(2001) final. 9 Anastas, P. T.; Warner, J. C. Green Chemistry (1998): Theory and Practice, Oxford University Press:
New York, p.30. 10
Based on Agenda 21: Chapter 19 - Environmentally Sound Management of Toxic Chemicals,
Including Prevention of Illegal International Traffic in Toxic and dangerous products
5
d) design of a risk management policy; e) capacity for implementation and enforcement; f) capacity for rehabilitation of contaminated sites and healing of poisoned persons; g) effective education programmes; and h) capacity to respond to emergencies.
Occupational health and environment are two sides of the same coin, since the measures we adopt to protect workers health will protect the environment and vice versa. The basic principle of prevention consists in substitution or reduction to the minimum of the hazardous chemical agents in the workplace. Prevention and management of hazards, and consequently chemical safety, are essential to contain and reduce related health and environmental risks.
2. INTRODUCTION TO CHEMICALS MANAGEMENT
Most frequently used chemicals: are some chemicals better or safer than others?
2.1 WHAT DO WE KNOW ABOUT CHEMICALS?
This unit will mainly address the following questions: 1. What are hazardous substances? 2. What do we know about them? 3. Do we have enough knowledge of their effects?
2.1.1 Getting to Know Basic Chemistry11
Chemicals substances are everywhere. All matter (i.e. liquids, solids and gases) is made of elements. An element is the simplest form of matter that exists. At present, there are 106 different elements - including oxygen, nitrogen, carbon - and many other substances composed of atoms. A single chemical element, standing alone, is a pure substance. When there is a combination of two or more elements, it is called a compound (for example, water (H2O)). At another level, a mixture is the name used to refer to a substance that contains more than one chemical element or compound, the separate constituencies of which, still retain their own properties. There are two different types of mixtures:
• Homogenous mixtures, known as solutions, which involve two or more substances (the solutes) dissolving into another substance (the solvent) (for example, salt or sugar dissolving in water, or gold into mercury); and
• Heterogeneous mixtures, known as suspensions, which are mixtures with definite, circumscribed composition (for example, granite, although a salad is probably the most typical example of this kind of mixture).
11
Chapter based on IPCS (International programme on chemical safety): Users’ manual for the IPCS
health and safety guides (1996), http://www.inchem.org/documents/hsg/hsg/hsgguide.htm (last accessed 14 April 2008)
Module aims: The module aims at:
• Providing basic information on hazardous chemicals, their toxicity, including properties and characteristics, and their effects on human and environmental health, particularly for workers;
• Introducing the concepts and principles of green chemistry; Learning outcomes: At the end of the session, the trainee will be familiar with:
• the terminology related to sound management of chemicals; • the types of effects on human health and the environment, including routes of entry of chemicals into the body;
and
• the concept of green chemistry.
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2.1.2 Name, Surname and “Nickname” af Chemicals: How Do We Refer To Them?
There are different ways to refer to and name a chemical. It can appear as the chemical formula, or it can be brought up by a common name that normally refers to the elements that make up the chemical compound (for example, hydrogen sulphide contains elements of hydrogen and sulphur). It can also be called by its trade name. Producers and manufacturers often choose to give “trade” or commercial names to chemical compounds or mixtures to make them easier to remember. There are different international identifications methods:
• The CAS registry number: each chemical is given a unique number by the Chemical Abstract Service (CAS), a division of the American Chemical Society. As of April 2008, there were 34,793,507 organic and inorganic substances, and 59,792,349 sequences in the CAS registry.12
• The RTECS number: is allocated by the Registry of Toxic Effects of Chemical Substances. It is a database of toxicity information on the health effects of the chemicals compiled from the open scientific literature.
However, not all toxicity information is free or available. • Another classification or numbering system involves the use of UN numbers or UN IDs that are used in the framework of international transport. They are four-digit numbers that identify dangerous goods, hazardous substances and articles (such as explosives, gases, flammable liquids, toxic substances, etc.).13
There are other nomenclature and referencing systems for classifying chemicals, including the IUPAC which has developed the International Chemical Identifier (InChI), and the EC-No and EC#, the latter ones being allocated by the Commission of the European Communities for commercially available chemical substances within the European Union mainly.
2.1.3 What Do Chemicals Look Like?
PHYSICAL FORMS OR “STATES” Chemicals are present in different physical forms, with the main ones being:
• Solid. This form is the least likely to cause chemical poisoning. However, certain chemical solids can cause poisoning if they get onto your skin, or into food;
• Dust. Dust is made of tiny particles of solids. Exposure can be either from materials that normally exist in dust form (for example, bags of cement), or from work processes that create dust (for example, handling glass fibres that produce toxic dust);
• Liquid. Many hazardous substances, such as acids and solvents, are liquids when they are at normal temperature;
• Vapour. This is the gas phase of a material that is found as a liquid under normal conditions. Tiny droplets of liquid which are suspended in the air are called mists; and
• Gases. Some chemical substances exist as a gas when they are at a normal temperature. However, some chemicals in liquid or solid form become gases when they are heated.
Other physical forms are aerosols, fumes, smokes, and fogs. Chemicals can change forms or “states” depending on temperature and pressure. For instance, water is liquid between 0-100 degrees Celsius (°C). Above 100°C it is in a gaseous state (steam) and below 0°C it is ice, a solid state. As a general rule, when the temperature of a solid is increased, it turns into a liquid (i.e. it melts). If the liquid is further heated, it boils and evaporates, generating smoke or fumes and turning into vapour or gas. If the surrounding pressure upon gases is increased without changes in temperature, they move from a gaseous state to a liquid one. Substances can change from one physical form to another, depending upon temperature and pressure. It is crucial to be aware of the possible movement of chemicals between physical forms due to surrounding and external changes, since
12
CAS Database Registry: http://www.cas.org/cgi-bin/cas/regreport.pl (last accessed 14 April 2008) 13
United Nations Economic Commission for Europe (UNECE)
http://www.unece.org/trans/danger/publi/unrec/12_e.html (last accessed 14 April 2008)
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some physical forms have a much greater negative impact than others. A substance, which might not represent a risk14
in a solid state, for example, can become hazardous to a worker in a liquid or gaseous form. PHYSICAL PROCESSES
They refer to the properties that chemicals have and which allows them to change from one form to another without involving a change in chemical composition. This happens through the following processes:
• The boiling point, which is the temperature at which a substance changes from liquid to gaseous state; • The melting point, which is the temperature at which a substance changes from a solid to a liquid state; • The flash point (open or closed cup), which describes the temperature at which a substance gives off enough
vapour to form a mixture with air that can be ignited –causing it to burn- by a spark or flame; • The auto-ignition temperature, which is the lowest temperature at which a substance burns without a spark or
flame. To contrast these two types of properties, the flash point for gasoline (petrol) is <-40°C, whereas for diesel it is at >62°C; their respective auto-ignition temperatures are at 246°C and 210°C.
The key physical properties are: • Solubility in water designates the amount (by weight) of the substance that can dissolve in one litre of water to
form a solution (homogenous mixture). This property is particularly relevant to possible water pollution and the potential impacts on aquatic organisms. In other words, high solubility compounds are normally a greater threat to aquatic organisms than low solubility compounds because they dissipate more quickly.
• Insolubility often refers to poorly soluble compounds, rather than to non-soluble compounds. In a stricter sense, there are very few cases where absolutely no material dissolves.
Other properties to mention are vapour pressure, relative vapour density, flammability, octanol/water partition coefficient, among others. PHYSICAL HAZARDS
The physico-chemical hazards encountered in the workplace level generally arise from explosive, flammable, extremely flammable, highly flammable or oxidizing15 substances. Often, of course, such substances will also present health hazards due to their toxicity.
• Toxicology is the science of adverse effects of chemical substances on living organisms. Even substances that are essential to our bodies, such as iron, can be toxic at high doses. Without enough iron, we would develop anaemia, but too much iron causes liver abnormalities.16
14
It is important to distinguish risk from hazard. For a detailed explanation, see “Unit 3: Prevention,
the best antidote to chemical exposure / Assessing hazards, risks and safety: safer handling, what else?” 15
Strong oxidizing agents are often very reactive chemicals, and, in contact with combustible
material such as paper, sawdust, fabrics or powdered metals, may form unstable mixtures, which constitute a risk of fire or explosion. A variety of substances can act as oxidizing agents. Oxygen on its own is a reasonably strong oxidizing agent, but other materials, such as fluorine, metal nitrates, potassium permanganate, hydrogen peroxide, sodium hypochlorite (bleach), or sodium dichromate are very effective.
Box 1. Types of toxic vectors There are three types of toxic vectors: chemical, biological, and physical.
• Chemical vectors include inorganic substances such as lead, hydrofluoric acid, and chlorine gas; organic compounds such as methyl alcohol; most medications; and poisons from living organisms;
• Biological vectors include those bacteria and viruses that are able to induce disease in living organisms; and
• Physical vectors include elements that seldom come to mind as being "toxic": direct blows, concussions, sound and vibration, heat and cold, non-ionizing electromagnetic radiation such as infrared or visible light, and ionizing radiation such as X-rays.
This course will focus on chemical toxicity. Source: Health and Protection Agency. Glossary. “Toxic Agent” http://www.hpa.org.uk/webw/HPAweb&Page&HPAwebAutoListName/Page/1153846673536?p=11538 46673536 (last
accessed 14 March 2009
8
• Ecotoxicology is part of toxicology, and was defined by Truhaut in 1969, as "the branch of toxicology concerned with the study of toxic effects, caused by natural or synthetic pollutants, to the constituents of ecosystems, animal (including human), vegetable and microbial, in an integral context”. Throughout the Manual, the term toxicology refers also to ecotoxicology.17
EXPOSURE TO CHEMICALS
For a chemical to exert an effect, there has first to be exposure. If there is no contact between a living organism and a chemical, no matter how toxic the chemical, the organism cannot possibly be harmed. Occupational exposure is a concern of highest priority to workers or farmers as they may face significant exposure to chemicals in their daily jobs. Workers are at the frontline of occupational exposure during the different phases of production, storage, handling, transport, use and disposal of chemicals. In addition, exposure may also occur in different and multiple ways (air, soil, water for drinking or irrigation in agriculture, etc.) through contaminated environments. Contamination can arise when waste are released into the environment, for example after industrial accidents or during industrial and agricultural processes. It is thus becoming increasingly obvious that human health, environmental contamination and chemical exposure are closely linked. Although some chemicals are less harmful than others, their combined effects should be taken into account to assess the level of exposure and the potential consequences on human health and living organisms. The dose or concentration is another aspect to consider. For instance, a highly toxic substance can be extremely harmful even if only very small amounts are present in the body. Conversely, a substance of low toxicity will normally not produce any toxic effect unless the amount present in the body is significant. There is a progression in severity of effects as the dose increases: it is the dose effect relationship. In addition to a chemical’s dose, its toxicity also depends on how long exposure lasts, also known as the duration of exposure. Single exposure is referred to as acute exposure, while repeated exposure over a longer time is called chronic exposure. Toxicological studies aim at assessing the adverse effects related to the different doses. To this end, they seek to establish the relationship between a determined dose and its effects on a variety of living organisms. The next section will introduce the major toxic effects that chemicals have on human health and the environment. The exposure pathway18 is an important notion that refers to the route a substance takes from its source (where the substance is first released) to its end point (where the substance ends: in the environment, on/inside the body), and how people come into contact with (or get exposed to) it.
16
International Occupational Safety and Health Information Centre (CIS), Chemical Safety Training
Modules, What is toxicology?, ILO, http://www.ilo.org/public/english/protection/safework/cis/products/safetytm/toxic.htm (last accessed 14 April 2008) 17
Truhaut, R, (1977), "Eco-Toxicology - Objectives, Principles and Perspectives", Ecotoxicology and Environmental Safety, vol. 1, no. 2, pp. 151-173. 18
Agency for Toxic Substances and Disease Registry (ATSDR): Definition of exposure pathway, http://www.atsdr.cdc.gov/glossary.html#G-D- (last accessed 14 April 2008)
TOXICITY Type of
substance, and its chemical and
physical properties
EXPOSURE � Type of exposure (how?) � Duration (how long?) � Dose (how much?) � Multiple xposure
Characteristics of the
biological body
EFFECTS of the
substance
Box 2. Exposure to chemicals: dose-effect relationship
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An exposure pathway is defined by five elements: • A source of contamination (such as factories which were closed down); • An environmental medium and transport mechanism (such as movement through groundwater); • A point of exposure (such as a private well); • A route of exposure (eating, drinking, breathing, or touching); and • A receptor population (people potentially or actually exposed).
When all five elements are present, the exposure pathway is termed “completed exposure pathway”.
WHAT ARE THE TOXIC EFFECTS OF CHEMICALS ON HUMAN HEALTH AND THE ENVIRONMENT? Hazardous chemicals are found in the tissues of nearly every person on Earth. Exposure to chemicals has resulted in several cancers and in a range of reproductive problems, including birth defects, development disorders and other diseases. The increasing number of cases and the constant exposure of individuals to a cocktail of chemicals have raised concern, particularly among workers. The terminology referring to the toxic effects of chemicals is complex and deserves particular attention. The terms “acute” and “chronic”, previously used to refer to duration of exposure, can also describe how long it takes for the effect of exposure to a certain chemical to appear, which is also very important data. Below are listed some of the most toxic effects chemicals can have on humans, as well as on biological organisms.
• Concentrated solutions of strong acids (sulphuric acid for example), or alkalis (such as caustic soda), can cause chemical burns to the skin. A chemical that destroys or damages (burns) living tissue on contact is corrosive. A splash of a corrosive liquid in the eye, for example, can result in permanent damage to eyesight.
• When a chemical produces local annoyance, pain or inflammation of the skin, eyes, nose or lung tissue, it is called an irritant. For instance, a common substance like hypochlorite, also known as bleach, has a corrosive and irritant effect when applied to the skin.
• A chemical causing difficulties to breathe by interfering with oxygenation of body tissues, is an asphyxiant. There are two types of asphyxiation: simple asphyxiation, whereby oxygen in the air is replaced by a gas to a level at which it cannot sustain life (lack of oxygen); and chemical asphyxiation, whereby a direct chemical action interferes with the body's ability to transport and use oxygen. Examples of chemical asphyxiants include carbon monoxide and cyanides.
Box 2 Classification of toxic effects of chemicals: definitions
• Acute effect – The term acute means “of rapid onset and short duration” and, with reference to chemicals, usually means a short exposure with an immediate effect (24 hours or less). While an acute exposure can result in an acute effect, it can also result in a chronic disease, e.g. permanent brain damage can result from acute exposure to trialkyl tin compounds or from severe carbon monoxide poisoning;
• Chronic effect – The term chronic means “of slow onset and long duration” and usually refers to repeated exposure with a long delay between the first exposure and the appearance of adverse health effects;
• Acute and chronic effects – A substance may have both an acute and a chronic effect. For example, a single exposure to high levels of carbon disulfide can result in unconsciousness (acute effect), but repeated daily exposure for years at much lower concentrations may result in damage to the central and peripheral nervous system, as well as to the heart (chronic effects). Another example, percloroethylene, known as the “universal solvent” for dry cleaning and other uses, can result in acute effects such as irritation and chronic ones such as cancer;
• Reversible (temporary) effect – An effect that disappears if exposure to that chemical ceases. Contact dermatitis, headaches and nausea from exposure to solvents are examples of reversible effects;
• Irreversible (permanent) effect – An effect that will have a lasting, damaging effect on the body, even if exposure to the chemical causing that effect ceases. Cancer caused by exposure to a chemical is an example of an irreversible effect;
• Local effect – The harmful effect of a chemical at the point of contact or entry to the
• body, e.g. burns to the skin; and
• Systemic effect – Occurs after the chemical has been absorbed and distributed from the entry point to other parts of the body. It can be caused by a number of chemicals, including lead, beryllium, benzene, cadmium and mercury compounds.
Source: IPCS (International programme on chemical safety) (1996). “Users’ manual for the IPCS health and safety
guides” http://www.inchem.org/documents/hsg/hsg/hsgguide.htm (last accessed 14 March 2009)
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There are a number of reactions and effects caused by exposure to chemicals, which are highly damaging and irreversible. When these effects occur, the organism is so severely affected, that it is not possible to restore it into the original health state in which it was before exposure, thus resulting in a permanent change to the organism. For example, chlorpyrifos, which is an insecticide on the market today, is used to kill insect pests by disrupting their nervous system; it is said to have an advantage over other products in that it is effective against a wide range of plant eating insect pests. However, it has proved to cause immune system abnormalities to individuals, as well as to animals other than the targeted insect pests. Such a chemical can have a sensitizing or immunotoxical effect causing allergic reactions. A person who reacts to a chemical will experience a heightened reaction to it, even at a very low dose, whereas the chemical will not be harmful for the majority of individuals at the same dose. Any subsequent exposure to that substance – whether through skin contact or inhalation - represents a risk to the health of a person who has been sensitized to it. Chemicals can also have a carcinogenic effect, meaning they cause cancer. Cancer is characterized by the manner in which abnormal cells in the body multiply and spread out of control. The key feature of cancer is the malignant or deadly way in which its cells crowd out sound/normal cells and interfere with the normal functioning of the body. For example, benzene, which is still used as a petrol additive or as an intermediate compound to manufacture other chemicals, has been classified by the International Agency for Research and Cancer (IARC) as carcinogen. For the record, one of benzene’s early uses in the 19th and early-20th centuries was as an after-shave lotion because of its pleasant smell. Additional effects of chemicals include a mutagen effect, which causes permanent damages to the DNA (deoxyribonucleic acid) in a cell. DNA is a molecule that carries the genetic information controlling the growth and functioning of cells. DNA damage in the human egg or sperm may lead to reduced fertility, spontaneous abortion (miscarriage), birth defects and genetic diseases. As many mutations cause cancer, mutagens are typically also carcinogens. Because some chemicals can adversely affect the reproductive capacity of women and men, and the un-born generations, they are said toxic to reproduction. They affect all phases of the reproductive cycle, as adverse effects on the developing organism can result from exposure before conception (either parent), during pregnancy, or between birth and the time of sexual maturation. Toluene belongs to that category; though, this product is largely used, especially as a common solvent to dissolve paints, paint thinners, chemical reactants, rubber, printing ink, adhesives and glues, lacquers, leather tanners, and disinfectants. Endocrine disrupters are chemicals that alter functions of the hormonal system, consequently causing adverse health effects in women and men, and their descendents. The possible health effects include breast and prostate cancer, reduction of sperm quality, and modified hormone levels. The children of exposed women can suffer from precocious puberty, vaginal cancer, deformation of reproductive organs, among other serious problems. There is growing scientific consensus that numerous industrial and agricultural chemicals have the ability to interfere with endocrine systems and hormonal activities of all animals including fish. One of the best-known effects is the feminizing of male fish. Some examples of substances known or suspected to be endocrine disrupting chemicals (EDCs) are pesticides as atrazine, 2,4-D, DDE, DDT, diazinon, diuron, endosulfan, fenthrothion, glyphosate, lindane, or industrial chemicals or breakdown products such as bisphenol A, dioxins, nonylphenol, PCBs, some phthalates.19 These effects may appear at extremelly low doses, generally below legally established limits of exposure. Another example involves bisphenol A, which is used to make plastic bottles and many other plastic products. Apart from its impact on workers, it has also proven to cause sex reversals in animals like the broad-snouted caiman - an alligator native to South America - and has also caused reproductive malformations in quail and chicken embryos. This substance is both toxic to reproduction and an endocrine disrupter. Some chemicals can have adverse effects on the structure and function of, both the central nervous systems (brain and spinal cord) and peripheral nervous system, causing muscular weakness, a loss of sensation and motor control, tremors, cognitive alterations, and a dysfunction of the autonomic nervous system. These types of chemical are known as neurotoxics. TPB is an acronym which refers to substances that are:
• “T”oxic for mammals and aquatic organisms; • “P”ersistent, given that they remain in the environment for long periods of time, degrading very slowly; and
19
Briefing note on Fish and Endocrine Disrupters, WWF, (1998)
http://www.ngo.grida.no/wwfneap/Publication/briefings/Fish.pdf (last accessed 19 December 2007)
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• “B”io-accumulative as they tend to accumulate in the body tissues of living organisms. For example, pesticides like aldrin, dieldrin and mirex.
COCKTAIL OF CHEMICALS: MULTIPLE EXPOSURE AND COMBUNED EFFECTS
Workers seldom use a single chemical in their daily jobs. Most times, they manipulate or are surrounded by two or more chemicals, to which they might be exposed via dermal contact (through the skin), inhalation (through the respiratory tract, including the lungs) or ingestion (through the mouth). In the same way, in their normal environment individuals are seldom exposed to a single substance. When two or more chemicals are in presence, they may interact with each other, which can alter the resulting toxicity. However, the resulting effect of chemical interactions can take different forms. Basically, the four types of combined effects chemicals that can have are: • Independent: when the chemicals taken individually produce different effects or have different modes of action, and do
not interfere with each other; • Additive: when the combined effect is equal to the sum of the effects of each agent taken alone. For instance,
organophosphate pesticides, such as dialiphos, naled and parathion are usually additive. Numerically it could be represented as 1+1=2;
• Synergistic: when the toxic effect resulting from the interaction is greater than the sum of individual effects. An example of increased risk is asbestos fibres combined with cigarette smoking: the risk of developing lung cancer after exposure to asbestos fibres is forty times greater for a smoker than for a non smoker. Numerically it could be represented as 1+1=4; and
• Antagonistic: when the respective effects of two or more substances neutralize one another (e.g. the way an antidote reacts to a poison). However, this type of interaction does not happen very frequently. For example, if dimercaprol binds with various elements such as arsenic, mercury and lead, the toxic effect will be less than what could be expected for dimercaprol alone. Numerically it could be represented as 3-2=1. There is not much information available that can help predict the likely effects of the potential interactions between hazardous chemicals. To be safe, or at least safer, chemical cocktails should be avoided or reduced to the lowest possible level.
DIFFERING REACTIONS: HYPER-SUSCEPTIBLE GROUPS
Each individual responds in a specific way to a chemical. Exposure to the same dose over a similar time period will thus induce different responses among different people. This principle also applies to all life on Earth. In the workplace, workers exposed to similar concentrations of the same chemical, at the same worksite, will not necessarily exhibit the same symptoms. There may be various reasons to that, including:
• Gender: women, because of a greater relative proportion of body fat, may be more susceptible than men to harmful effects of solvents which accumulate in fat tissues, for instance;
• Age: children and the elderly are generally more susceptible to chemical hazards; • Race: certain races may be genetically more vulnerable to certain chemical exposures; • Lifestyle factors and nutritional situations may also have a considerable effect on the action of some compounds;
and/or • Individual variations: different individuals with similar characteristics such as gender, age, etc. may have different
sensitivities. HOW IS CHEMICAL TOXICITY DETERMINED? There are two main sources of information on health effects resulting from exposure to chemicals. The more frequently used source consists of toxicity studies on laboratory animals. The second source consists of studies on human populations. Laboratory animals are those that undergo tests to measure the toxicity of a chemical before people and animals are widely exposed to it. Different animal studies can be undertaken. Acute toxicity test (short-term) gives, for example, the LD50 (lethal dose) and LC50 (lethal concentration) indices of toxicity, which are two widely used indicators for toxicity. LD50 (lethal dose) refers to the amount of the substance that kills 50% of the test population of experimental animals when administered as a single dose. The LD50 is usually expressed as the mass of substance administered per unit of mass of the
�Avoid mixing several chemicals. The combination may result in very dangerous effects.
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subject, such as grams of substance per kilogram of body mass. LC50 (lethal concentration), used for inhalation experiments, is the concentration of the chemical in air that kills 50% of the test animals in a given time (usually four hours). In general, the smaller the value, the more toxic the chemical. The opposite is also true: the larger the value, the lower the toxicity. It is also important to know that the actual LC50 value may be different for a given chemical depending on the route of exposure (dermal, oral, or respiratory). For example, if the LC50 value for a dermal route of exposure rates a chemical as extremely toxic, then the skin should be protected when handling it, using clothing, gloves, etc. made of an appropriate chemical-resistant material. Alternatively, if the LC50 value for a respiratory route of exposure that indicates the chemical is relatively harmless, then respiratory protective equipment may not be necessary (as long as the oxygen concentration in the air is in the normal range - around 18%). To compare the toxic potency or intensity of different chemicals, researchers must measure a common parameter. One way is to carry out lethality tests (the LD50 tests) by measuring how much of a chemical is required to cause death. They are very crude indices of toxicity, which give a very rough or gross figure, and are undertaken in order to compare the lethal toxicity of different chemicals. These tests do not give adequate data on carcinogenicity, teratogenicity or reprotoxicity. Many national and international bodies are now trying to modify or replace the LD50 and LC50 tests by simpler methods, such as the fixed-dose procedure, as fewer animals are involved. This requires only a small number of animals, and analysts can evaluate a chemical’s toxicity without animals dying as the ultimate result. The lowest dose that causes a toxic effect (TDLO), or the Lethal Dose Low (LDLo) are other sources of toxicity information. There are other animal studies undertaken on mutagenicity, reproductive tests, to name but a few examples. Conclusions related to chemicals toxicity are not all based on laboratory tests. Human evidence is also a very important source of information, especially in the case of hazards and effects in the workplace (occupational health), where most information come from reviewing specific cases and situations. Epidemiological studies are another important source of information, basing investigations on the health of a group of people to establish whether they are affected by the chemical to which they are exposed at work or via the environment. Although epidemiological investigations provide the most reliable proof of the adverse effect of a given chemical, it also has obvious disadvantages. Few chemicals have been submitted to epidemiological investigations because these analyses are very expensive compared to other tests. In addition, validation of the results requires a large number of exposed workers, and above all, it does not really act as a prevention measure: many people would have already been exposed and suffered illness or death before the investigations could happen. Another important concept is threshold dose or threshold concentration, which refers to the minimum dose required to produce detectable responses in a given group of population, for example workers. The no-observed-effect-level (NOEL) refers to the greatest dose of a chemical, which causes no detectable health effect. And the lowest-observed-effect-level (LOEL) refers to the lowest dose of a substance which causes a detectable health effect. IS THERE A TOLERABLE TOXICITY LIMIT? The question of trying to establish a threshold based on the toxicity of the substance is used as the basis to estimate other indicators, as for example, the tolerable daily intake (TDI), which is the daily intake of a chemical contaminant over a lifetime without appreciable health risk. However, it is impossible to examine every situation that might lead to toxic effects, and therefore potential effects may be missed. Whether there is a threshold dose, below which there is no toxic effect or an acceptable exposure dose, is very controversial because of the nature of the indicators. To be able to handle and benefit from the properties of a chemical safely, i.e. in a way and at doses which ensure that overall exposure of people and/or other organisms is kept below defined and tolerable limits, it is fundamental to know how poisonous or toxic it is. However, the notion of “tolerable” limit is not a fixed standard. The perception of what is “tolerable” is clearly influenced by economic, environmental, social and political factors. In particular, it is closely linked to the probability of occurrence of
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several factors - including suffering, injuries or disease - and social acceptance of associated risks in comparison to expected benefits arising from the direct use of a chemical or as part of a productive process. It is important to be familiar with the systems of classification of toxicology, as they are the basis for determining occupational limit values. However, the limit values might vary from one country to another.20 In deciding what constitutes a tolerable exposure, it seems necessary to establish principles or guidelines for action. For example, it may be prudent and necessary to demand the elimination of certain substances from the workplace if they can significantly damage human health or the environment. Safe use of chemicals implies: • Availability of information: It is important that toxicological information through testing methods be made available, as the
toxicity and effects on human health and the environment of many substances that are already commercialized are still unknown. It is important to remember that absence of evidence of risk is not the same thing as evidence of absence of risk. With precaution as a guiding principle, it is logical to demand “zero tolerance” for substances whose effects are not yet known. This is valid for new substances as well as existing ones which are already on the market.
• Promoting a culture of prevention: Understanding toxicological information is very important for workers’ safety as
users. It is important to be familiar with the systems of classification of toxicology, as they constitute the basis for determining occupational limit values, and therefore building a precautionary approach to the use of chemicals in the workplace.
However, in addition to a lack of toxicological information for many substances, the toxicological results sometimes lead to different interpretations from one legal source to another. For example, formaldehyde, which is used as solvent and adhesive, is classified by the International Agency for Research on Cancer (IARC) in Group 1, which means “the agent (mixture), is carcinogenic to humans”, while the European Union considers it to be part of Category 3 in its classification, which includes substances with possible carcinogenic effects to humans, but for which insufficient information is available to make a satisfactory assessment. Therefore, prevention must always be the leading strategy. In decisions relating to chemical safety, the toxicity of a substance is less important than the risk associated with its use. It is fundamental to adopt prevention and control policies of hazards in the workplace. As part of that effort, the promotion of a safety culture should take into account the common belief that all accidents can be prevented. In the context of Safe Use of Chemicals, elimination is the main objective. Yet, whenever possible - which is often the case -prevention measures need to be implemented. Prevention measures should focus first on the cause of emission:
! The “black-list” of substances for which elimination is a priority includes carcinogenics, mutagens, reprotoxic
agents, endocrine disrupters, sensitizers, neurotoxics, and toxic, persistent and bio-accumulative substances (TPB).
For these chemicals, public interest groups advocate No tolerance! Exposure should be zero.
Box 4. The case of aldrin This was a pesticide largely used in the 1950s, to kill soil insects such as termites and grasshoppers in order to protect crops such as corn and potatoes. However, it has proven to be a persistent organic pollutant (POP) with carcinogenic and mutagenic effects. As early as the 1970s, it was severely restricted and banned in several countries, and in 2004 the parties to the global Stockholm Convention on Persistent Organic Pollutants agreed to eliminate its production, use and release. Source: IPCS International Programme on Chemical Safety, Health and Safety (1989). “Aldrin and Dieldrin Health and Safety Guide”. Guide No. 21, http://www.inchem.org/documents/hsg/hsg/hsg021.htm (last accessed 17 December 2007) and Stockholm Convention on Persistent Organic Pollutants http://www.pops.int/
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1. Priority 1 - Eliminate risks: ensure less risky situations, through changes in the productive process or substitution of dangerous substances;
2. Priority 2 - Reduce and control risks by adopting measures at the source of the exposure such as isolation, aspiration, ventilation systems, and other actions; and
3. Priority 3 – Workers’ protection, in case the risks are not fully eliminated, or properly reduced and controlled (as per priorities 1 and2): the worker will be provided with individual protective equipment.
It is worth noting that some cases may require a combination of the three prevention measures above-mentioned. When all these prevention measures cannot be taken, and the risk is not fully eliminated or at a minimally acceptable degree, technical evaluations in the form of tests to workers and the workplace environment are undertaken to compare the actual exposure in the workplace with threshold limit values (TLV). Where TLV are exceeded, corrective measures should be demanded. TLV are thus good tools for practical action. However, exposure below the TLV does not fully guarantee safety, and prevention measures still need to be implemented. The preferred strategy should be first and foremost that of anticipating and preventing the release rather than relying on an after-the fact approach based on remediation and treatment. • Calling for a proper regulation of chemicals: Often decisions are made by national authorities based only on scientific
data or on the interests of specific economic groups. Stakeholders are not involved, while some of them, like workers, farmers are at the frontline of chemical exposure, and should thus have a real say on regulation of chemicals.
Given the severe risks associated with chemical contamination, channels need to be created to guarantee the participation of workers, trade unions, farmers and public interest groups, in decision making processes, as a democratic principle.
2.2 PAINFUL, DEADLY ENCOUNTERS WITH POISONS
This unit will address the following questions:
1. What are the effects of hazardous chemicals on human health? How does the body process them? 2. What are the effects of hazardous chemicals on the environment? How does the environment process them?
Workers and Hazardous Substances: A Perilous Relationship
ROUTES OF EXPOSURE
Chemicals can enter the human body and other living organisms through a number of different pathways, known as “routes of exposure”; each pathway may react differently to the toxicity of a chemical. The type of route of exposure is thus critically important in determining how harmful a chemical can be. The four major routes of exposure are: penetration through the skin or dermal absorption, through the respiratory tract and especially the lungs or by inhalation, through the digestive tract or by ingestion, and through the eyes. The most common forms of occupational exposure are the inhalation of gases, vapours or airborne particles resulting in penetration through the lungs, and dermal contact, especially with liquids, which can be easily absorbed through the skin. The ingestion of poisons is common where general hygiene conditions are poor. • Inhalation: respiratory tract, lungs: The lung is a common route of exposure. Unlike the skin, lung tissue is not a very
protective barrier against chemical exposure. In industry, inhalation is the most significant route of exposure. The substances irritate the mucous membrane of the upper respiratory tract and respiratory passages within the lungs. Thus, the occurrence of irritation may indicate the presence of toxic chemicals. However, certain gases or vapours do not induce any irritation and, when unnoticed, penetrate deeply into the body through the lungs where they may cause injuries, or even reach the bloodstream. The entry of dust particles into the body depends on their size and solubility. The bigger they are, the more difficult it is for them to penetrate. ! Exercise extreme caution with chemicals in the form of vapour, fumes, dust or gas, as they can
easily enter the body through breathing.
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• Dermal absorption: skin contact - Chemicals that pass through the skin are nearly always in a liquid form. Dusts,
gases or vapours do not generally pass through the skin unless they are first dissolved in moisture at the surface of the skin. Chemicals that can dissolve easily in fats (lipids) are much more likely to penetrate the skin than chemicals that are soluble in water. However, gaseous and solid chemicals can also pass through the skin: for example, highly toxic gases such as sarin and parathion, penetrate the skin without causing overt damage. If the skin is damaged by cuts or abrasions, or diseased, chemicals (including in a solid form) may penetrate easily and even more quickly into the body.
• Ingestion: digestive tract, mouth: Ingestion is another way in which chemical substances can enter the body. Eating
at the workstation, where food and drink may be contaminated by vapours in the air, or smoking with contaminated hands, should be strictly prohibited. Besides, chemical substances can be ingested when inhaling particles through the throat, since they can be swallowed and pass both into the digestive system and the lungs.
• Absorption through the eyes: Any chemical, in the form of a liquid, dust, vapour, gas, aerosol or mist can enter the
eyes. It is common to incur eye splashes or eye contamination due to exposure to chemicals in the workplace. Small amounts of chemicals can enter the eye by dissolving in the liquid surrounding the eye. The eyes are richly supplied with blood vessels, into which many chemicals can pass after penetrating the outer tissues. The eye may be damaged in the process, depending on whether the chemical is corrosive or not. The different mucous membranes in the body – in the mouth, gastrointestinal tract, nose, vagina, etc. – can also be easy ways for the chemicals to enter the body.
HOW ARE CHEMICALS PROCESSED WITHIN THE BODY? When a chemical enters the human body or any living organism, it goes through different processes. It is transported into different parts of the body where it can be metabolized (transformed), accumulated (stored) and/or excreted (expelled). • Metabolizing is the process by which the body renders an alien chemical more easily extractable and/or less toxic.
For most chemicals, the liver is the main site of transformation, but other organs such as the kidneys are also capable of metabolizing chemicals, sometimes into a resulting product that is also toxic.
• Excretion is the process by which unwanted chemicals are removed from the body, for example, by exiting through
urine. However, these substances may cause damage to internal organs prior to excretion. Chemicals that undergo a slow metabolism or excretion are often stored in various tissues inside the body. Sustained exposure may increase the amount of chemical present in tissues. Chemicals that are stored in this way are said to accumulate. ADVERSE EFFECTS OF CHEMICALS ON HUMANS
The toxic effect of hazardous substances is not the same in all organs. “A local effect refers to an adverse health effect that takes place at the point or area of contact. The site may be skin, mucous membranes, the respiratory tract, gastrointestinal system, eyes, etc.
• Systemic effect refers to an adverse health effect that takes place at a location distant from the body’s initial point of contact and presupposes absorption has taken place. Substances with systemic effects often have “target organs” in which they accumulate and exert their toxic effect.”20 The central nervous system is the target organ of toxicity most frequently involved in systemic effects. The blood circulation system, liver, kidneys, lungs and skin follow in frequency of systemic effects. Muscle and bones are target organs for a few substances, causing for example degenerative osteoarthritis, osteoporosis;
20
Chem Safe: Local vs Systemic Health Effects
http://learn.caim.yale.edu/chemsafe/references/localvs.html
! Watch out while eating and drinking at your workstation! You may be introducing hazardous
chemicals into your digestive system, because the substance may be coating the food or eating utensils.
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• Skin is the largest organ in the human body. It provides a protective cover to the body but can fail to do so if the toxic load is overwhelming. A number of substances can penetrate healthy intact skins and pass into the blood stream. Phenol is a substance that can ultimately result in death after exposure and penetration through the skin. The vast majority of work-related skin diseases are contact eczemas, irritation and inflammation. This condition can be either a non-allergic or allergic reaction to chemical substances. Examples of common contact sensitizers are several colorants and dyes, metals such as nickel and its salts, chromium and cobalt salts, organomercuric compounds, the monomers of a number of acrylates and methacrylates, rubber additives and pesticides. In practice chemical skin injury is also influenced by environmental factors such as humidity and heat;
• Lungs are the major routes through which toxic substances found in the workplace enter the body. It is also the
first organ to be affected by dusts, metal fumes, solvent vapours and corrosive gases. Allergic reactions may be caused by substances such as cotton dust, TDI (toluene disocyanate, used in the manufacture of polyurethane plastics), and MIC (methylisocyanate, used in the production of carbaryl insecticide). Exposure to silica (quartz) or asbestos dust cause pneumoconiosis or lung cancer.21 Other substances, such as formaldehyde, sulphur dioxide, nitrogen oxides and acid mists may cause irritation and reduce the breathing capacity;
• The nervous system is sensitive to the hazardous effects of organic solvents. Some metals can affect the
nervous system, especially heavy metals such as lead, mercury and manganese. Organophosphate insecticides such as malathion and parathion interfere severely with the transmission of information in the nervous system, leading to muscular weakness, paralysis or sometimes death. Because it is the nervous system, almost any of the many functions it controls can be inhibited by neurotoxicants - speech, sight, memory, muscle strength and coordination for example;
• The circulatory system is a target for solvents. Blood cells are mainly produced in the bone marrow. For
example, when benzene affects the bone marrow, the first signs are mutations in the blood cells called lymphocytes. Lead and its compounds are other classic examples of chemicals toxic to the blood system. Chronic lead poisoning may result in reduced ability of the blood to distribute oxygen through the body, a condition known as anaemia;
• The liver is the largest of all internal organs and has several important functions. It is the body’s “purification plant”
which breaks down substances unwanted in the blood. As the liver shows a considerable reserve capacity, symptoms of liver disorder appear only in serious diseases. Solvents such as carbon tetrachloride, chloroform and vinyl chloride, as well as alcohol, are hazardous to the liver;
• The kidneys are part of the body’s urinary system. Their main function is to excrete the waste products
transported by the blood from various organs and ensuring that body fluids contain an adequate blend of various vital salts. They also maintain the acidity of the blood at a constant level. Solvents may irritate and impair kidneys’ function. Carbon tetrachloride is the most hazardous to the kidneys. Turpentine in large quantities can also prove harmful: “painter's kidney” is a well-known condition related to occupational exposure. Lead and cadmium are also common kidney damaging substances; and
• The immune system is a highly sophisticated defense system that protects the body from invading organisms,
tumour cells and external agents. Immunotoxicants can have three different effects on the immune system: they can suppress the immune system; make it hypersensitive, which causes allergies; or they can cause the immune system to attack its host, which is known as autoimmunity.
As indicated in the previous section, exposure to hazardous substances can also affect the male and female reproductive systems as well as have a genetic impact, raising the possibility of transmission to descendents.
Environment and Hazardous Substances: More than Just a Difficult Relationship
ORIGIN OF CHEMICAL POLLUTION OF THE ENVIRONMENT22
Hazardous manufactured chemicals are released from the workplace into the environment in the form of liquids, dust, fumes or gas. They can be planned (part of the production process) or unplanned releases (industrial accidents and leakages).
21
Respiratory diseases from exposure to asbestos include asbestosis, lung cancer and mesothelioma. 22
Ramon Mestres (2006). Hacia una producción química sostenible. University of Valencia
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The planned release of chemical substances into the environment can be in the form of: • Waste: the leftovers of dangerous products, their containers and any material contaminated used in the productive
process (cloths, gloves, sawdust, etc.) that are either placed in dumps, treated in specialized plants or burned in incinerators. Waste can be also in the form of: � Emissions released into the environment through chimneys, systems of extraction or ventilation and
windows; and � Spillage through drainages and pipes.
• Manufactured goods: During their intended use, manufactured goods may release chemicals into the
environment. At the same time, many chemical substances free themselves to the environment as finished products while used by the consumers. These include products like paint, plastics, cosmetics, electrical appliances and electronics, as well as exhaust fumes from motor vehicles.
These chemicals, once released, will eventually interact with air, soil and water. As a result of economic activity, many chemicals are released into the environment. They are not only generated by the chemical industry, but also by other sectors which contribute significantly, for example agriculture, car manufacturing, construction, energy production, extraction of fossil resources and minerals, metallurgy, pharmaceuticals, textile or transport, among others. Box 5. Origin of chemical contamination
Source: Ramon Mestres (2006). Hacia una producción química sostenible. University of Valencia
ADVERSE EFFECTS ON THE ENVIRONMENT
Some chemical pollutants affect the air, surface water, groundwater, soil or sediments, more than others. Different species will react to the same chemical in different ways and to a different degree. However, aquatic life has been proven to be the most vulnerable medium, where most effects first appear. However, what is highly toxic to aquatic life may not be toxic to birds. Similarly, some substances have a greater impact on other living organisms than on humans. Rather than focusing on defining and analysing the specific characteristics of air, soil and water contamination, the list below presents briefly different types of exposure of human beings and other living organisms to polluted environments: • By breathing polluted air. The World Health Organization estimates that 4.6 million people die each year from causes directly attributable to air pollution. Many of these deaths are attributable to indoor air pollution.23 In addition, polluted air makes the process of photosynthesis from plants more difficult;
23
WHO Member State (2002). Estimated deaths & DALYs attributable to selected environmental risk
factors http://www.who.int/entity/quantifying_ehimpacts/countryprofilesebd.xls (last accessed 19 December 2007)
ENVIRONMENT: Media (air, soil, water) and Living Organisms (animals, plants)
Energy and Transport
Chemical industry
Activities that use synthetic products
Metallurgy / Industrial metals
Exploration, Production and Refining
Renewable Resources
Metals and Mining
Fossil Resources (coal, gas, oil) Mineral Resources Beneath the Earth’s surface
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Animals and plants are exposed to chemicals through their functions in the food chain. Each successive step up the food chain causes a stepwise concentration of pollutants, for example in the case of heavy metals (e.g. mercury) or persistent organic pollutants (e.g. DDT, aldrin). This mechanism is known as biomagnification or bioaccumulation. For example, a substance found at a certain concentration in plankton will be at a higher concentration in small fish that eat the plankton, higher still in big fish that eat small fish, and higher still in bears or seals that eat big fish. GLOBAL ENVIRONMENTAL IMPACTS OF CHEMICALS
The following pollution mechanisms and situations are among the most far reaching. They are both interlinked with one another and unleashed to other mechanisms. Chemicals released as smoke and dust from factory chimneys will eventually fall to the earth’s surface as dust or in the rain. For example, the effects of sulphur and nitrogen oxides released in industrial areas have contributed to acid rain. These substances are emitted into the atmosphere, where they undergo chemical transformations, and are absorbed by water droplets in clouds. The droplets then fall on earth as rain, snow, mist, dry dust, hail, or sleet, even far from the countries where they were emitted. This phenomenon is called acid rain because it increases the acidity of the soil, and thus affects the chemical balance of lakes and streams, with a significant impact on the entire ecosystem. The Earth’s atmosphere has different layers. One of them is the ozone layer, which contains relatively high concentrations of ozone (O3), a molecule that is continuously produced and destroyed through natural processes. The ozone layer plays an extremely important role in absorbing the biologically harmful part of the ultraviolet rays that come from the sun. However,
Box 6. A tragic story: the 1984 Bhopal Disaster On the night of 2 December 1984, over 35 tons of toxic gases leaked from a pesticide plant in Bhopal owned by the US-based multinational Union Carbide Corporation (UCC)'s Indian affiliate Union Carbide India Limited (UCIL). In the next 2-3 days more than 7,000 people died and many more were injured. Over the last 21 years, at least 15,000 more people have died from illnesses related to gas exposure. Today more than 100,000 people continue to suffer chronic and debilitating illnesses for which treatment is largely ineffective. Source: Amnesty International USA. “DOW Chemical Company (DOW), Union Carbide Corporation and the Bhopal Communities in India” http://www.amnestyusa.org/Business-and-Human-Rights/Dow- Chemical/page.do?id=1101668&n1=3&n2=26&n3=1241 (last accessed 14 March 2009)
Box 7. A tragic story in Africa, today More than 50,000 tonnes of obsolete pesticides have been stockpiled in Africa contaminating tens of thousands of tonnes of soil. While more than 11 million cases of pesticide poisoning occur annually in Africa, few African countries have specialized centres to deal with it. However, the new multi-stakeholder Africa Stockpiles Programme (www.africastockpiles.org) is taking action to clean up obsolete pesticides across Africa and to help prevent reaccumulations. In addition, the extension of agriculture and corporate marketing have contributed to increased use of agricultural chemicals. In many places, small farmers have abandoned traditional and more environmentally-friendly practices under pressure to engage in the market, to produce improved crops and to increase yields. In Africa, despite the poor levels of comparable data over the last five decades, trends indicate an increase in the concentration of nitrates and phosphates at river mouths. Source: Monosson, Emily. UNEP (2007) “Chemicals use in Africa: opportunities and risks”. Encyclopaedia of Earth http://www.eoearth.org/article/Chemical_use_in_Africa:_opportunities_and_risks (last accessed 18 March 2009)
Box 8. Ecosystems An ecosystem is a natural unit consisting of all plants, animals and microorganisms functioning in a defined area, together with all the non-living physical features of the environment. Sometimes when chemical accidents occur, major attention is focused on the largest animals, yet all species, as well as humans, have a key role to play in the functioning of the ecosystem. Source: World Institute For Conservation & Environment (Wice). “Nature Worldwide: Ecosystems, The Ecosystem concept” http://www.ecosystems.ws/the_concept.htm
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the release of chlorofluorocarbons (CFCs) which were widely used as refrigerants, propellants, plastic from blowers and cleaning agents for electronic circuitry has caused a big reduction in the ozone concentration, known as ozone depletion. Awareness of the problem was reflected in the signature/ratification of the Montreal Protocol in 1987; the measures taken under this agreement have enabled significant improvements in the situation, but there is a still a long way to go. Climate change, also called global warming in mainstream media, receives a lot of attention and news, as one of the major challenges humanity will have to face during this century, with impacts set to be critical: a rise in sea level, increased desertification, and melting of glaciers, among others. Initially, climate change is a natural cyclical phenomenon; yet it has been seriously and adversely altered by human activities, most specifically these involving anthropogenic emissions (i.e. caused by human activities) of the so-called greenhouse gases (GHG). The use of fossil fuels for transport and power generation (vital to both the economy and households) are the main contributors to GHG emissions. Other factors, including land use, deforestation, or the above-mentioned ozone depletion also contribute to climate change. As this brief review shows, the environment is on the receiving end of a wide range of hazardous substances. Therefore the promotion of different and sustainable chemistry is needed, as it is a struggle for the future of the planet, the quality of life for humankind and the survival of other species. PROCESSING OF CHEMICALS IN THE ENVIRONMENT
There are numerous differing views regarding the capacity ecosystems have to confront and react towards hazardous chemical substances. Therefore, the question is, how are they processed in the environment? Depending on a number of complex factors, four strategies in particular can help answer that question. The environment has a given capacity to biodegrade toxic substances, enabling them to be broken down and to decompose. However, some substances are resistant to decomposition processes. Specific ecosystems can adapt or deteriorate which, after several changes, might lead to varying levels of loss of diversity, including loss of variety and complexity. Extinction of a species or group of species could be the last and most catastrophic step that would contribute to reduced biodiversity. A species is declared “extinct” when the last individual that belongs to it dies, although the capacity to breed and recover may have been lost long before that point.
PREVENTION, THE BEST ANTIDOTE TO CHEMICAL EXPOSURE
This unit will address the following questions:
1. How do we assess hazards and risks? 2. How do we ensure safe handling?
Assessing Hazards, Risks and Safety: Safer Handling, What Else?
A historical review of chemicals would highlight a set of positive applications and benefits such as medicine, solutions for plague control, detergents, cosmetics, food additives and preservatives, as well as processes in the textile and electronic industries or in the construction sector for example. These benefits arose from the development of chemistry as a scientific discipline, and from the production of chemicals and synthetic materials on an industrial scale. However, according to ILO, the recent average number of deaths attributable to occupational exposure to hazardous substances is estimated at approximately 440,000 a year (or 20 per cent of all work-related fatalities). 25 Additionally, hazardous substances may also have harmful impacts on the environment, as indicated in the previous unit. Environmentally sound management of toxic chemicals encompasses safe manufacture, storage, transport, use and disposal of hazardous chemicals. In other words, it is necessary to develop a proper form of management for chemicals that takes into account the whole life cycle, from manufacture to disposal - a cradle-to-grave management.
�There are no safe chemicals!
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But, how to achieve this? In assessing hazards and risks, key questions to address would be:
• Can all these negative effects on workers, communities and the environment be avoided? • Has enough been done yet? • What should be the role of prevention?
Whenever individuals or the environment become exposed to hazardous substances, remediation/decontamination measures should be deployed in order to minimize the toxic effects. However, prevention should be the first step to avoid contamination and exposure of individuals and the environment to toxic products, or, at least, to keep it under maximum “tolerable” levels. Additionally, for most chemicals, there often is no “proof” or “near proof” of adverse effect; yet in the meantime, an even greater number of workers might be exposed. This is why prevention is so crucial to chemical risk management. DEFINITIONS
A definition of key concepts and terms is necessary: • Hazard: It is the source of danger. It can be defined as the set of inherent properties of a chemical, mixture of
chemicals or processes that has the potential to adversely affect the environment or the organisms it contains, during production, usage or disposal.
• Risk: It is important to distinguish risk from hazard. Hazard refers to the intrinsic properties of a chemical, whereas risk refers to the chance or probability that the chemical will cause an adverse health or environmental effect.
If there is a high risk that a certain chemical will cause cancer to exposed workers, then it is very likely that some of those workers will develop cancer. If the risk is low, then it is less likely that the workers will develop cancer. However, even if the risk of some health effect is low, the chemical in question is still a hazard. Depending on the circumstances, a “low risk” may be acceptable to the people exposed. Determining the “acceptable risk” is part of the process for setting safety standards. “Setting safety standards” is not a scientific but a political issue. Therefore, it is important that workers have a say in their definition.
• Risk assessment involves identifying the origin of the hazard (the chemical of concern, for instance, and its adverse effects, target populations and conditions of exposure), characterizing the risk, assessing exposure (by modelling, measuring or monitoring), and estimating the risk. Thus, it consists of identification and quantification of the risk resulting from a specific use or occurrence of a chemical, and takes into account the potential harmful effects on individuals of using the chemical in the manner and amount proposed, as well as all possible routes of exposure.
• Risk management covers the whole range of actions taken to prevent, minimize or otherwise control specific risks
posed by a certain chemical or situation. This also refers to the search for substitutes for problematic chemicals, or for new and different processes to avoid the use of chemicals.
In this regard, the notion of safety is even more difficult to define than risk or hazard. The safety of a chemical, in the context of human health, is the extent to which a chemical may be used in the amount necessary for the intended purpose, with a minimum risk of adverse health effects. It can also be defined as a "socially acceptable" level of risk. But it is usually unclear which part of society is judging the risk. Workers that are exposed to the risk are likely to be more concerned about the safety of a chemical than others are. Therefore, it is very important to question statements such as "this chemical is safe" or "there is a high level of safety when using this chemical". Safety is a subjective concept, which needs to be properly defined in practice.
�It is always better to anticipate, rather than to rely on an after-the-fact approach.
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Precautionary Principle
As part of the prevention culture, the precautionary principle is a key driving notion. The precautionary principle is a moral and political principle which states that if an action or policy might cause severe or irreversible harm to the public, in the absence of a scientific consensus that harm would not ensue, the burden of proof falls on those who would advocate taking the action.24
Alternatives: Substitution Principle Substitution is one of the most important preventive techniques, given that it seeks to eliminate a certain risk at its source, through the implementation of significant changes in the productive process. These changes can be grouped in three levels:
• Substitution of an auxiliary substance or primary resource for an another without affecting the productive process, Substitution of equipment and procedures without affecting the production process, and/or
• Substitution of an auxiliary substance or primary resource in an equipment, with changes in the production process.
GREEENING OUR CHEMICAL WORLD The unit will address the following questions:
• Is it possible to develop a different chemistry? • What is “green” chemistry?
It is often argued that the consequences of hazardous chemicals on public health and the environment should be understood as a necessary part of the development of so-called modern societies, which bear “socially accepted” side effects. Yet, is the current mainstream chemistry known thus far the only possible way forward? Is there no possibility to move towards more sustainable, clean production models? Rather than the existence of chemistry itself, as it has been largely practiced over the past decades, the question relates to the types of chemicals, their roles, as well as the principles and criteria that should provide the basis for deciding which chemicals should be produced and to what ends. Chemistry is the basis of life: we breathe O2 (oxygen), we drink H2O (water), we expel CO2 (carbon dioxide), and when we die we become CH4 (methane) or if cremated turn into PCDD and PCDF (dioxins and furans). The development of chemistry should thus be compatible with the development of life and the protection of the environment.
What are the Limits of the Current Chemistry?
Two problems can be identified in today’s chemistry, among others: Occupational exposure and human health risks, and environmental pollution. The relationship between social, occupational and environmental risks is increasingly recognized and integrated in the decisions regarding the production and use of chemicals.
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Raffensberger C, Tickner J (eds.) (1999). Protecting Public Health and the Environment:
Implementing the Precautionary Principle. Island Press, Washington, DC
�“It is a truth very certain that when it is not in our power to determine what is true, we ought
to follow what is most probable.” René Descartes (1596-1650).
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At the same time, other significant circumstances affect even the viability of the chemical industry in a relatively near future. The dependency of current chemistry on fossil fuels requires close attention: an overwhelming volume of products and synthetic materials are made from organic compounds based on fossil materials, primarily petroleum. Therefore, the variation of prices and production of petroleum is set to affect the chemical industry. It is therefore legitimate to wonder whether we are moving from a peak oil scenario to a peak chemicals scenario.25
It is important and necessary to identify alternative sources of organic renewable materials to ensure that the chemical industry remains the supplier of products and materials for the human wellbeing. The production and use of chemicals have not only expanded quantitatively, but also geographically. Africa, but also Latin America and Asia are becoming dumping grounds for chemical wastes, while chemical industries are also relocating increasingly into these countries, where there is less fiscal and regulatory oversight and pressure. It is expected that there will be a significant shift in the production of chemicals from OECD countries to non-OECD countries. It is estimated that the developing world will increase its share from 23 per cent of global demand for chemicals and 21 of production in 1995 to 33 and 31 per cent, respectively, by 2020.26
It is essential to strengthen chemicals regulations nationally and internationally. It is also necessary to promote development and to base production on cleaner and safer technologies. The strengthening of chemicals regulation and the promotion of cleaner and safer technologies will be the best preventive measure to anticipate and avoid occupational and environmental exposure to hazardous substances as well as possible accidents.
Green Chemistry is the Key! Can the Door Be Unlocked?
Taking into account that all toxic chemicals are dangerous, and that there is no possibility to eliminate risk completely, but at least to reduce it as much as is feasible, it seems logical to develop a chemistry which is as little harmful as possible. Substitution of products and processes is a very valuable and necessary component in daily practices and production, and should be promoted. However, adopting a chemical-by-chemical/individual substance substitution approach is too slow, due to the large number of chemicals already on the market. It needs to be accompanied by the promotion of a new conception of chemistry, a sustainable chemistry or green chemistry. Green chemistry is based on the application of a series of principles by which the use or generation of hazardous substances is reduced or eliminated in the design, manufacture and application of chemical products, 29 by using renewable raw materials, manufacturing products that are non-toxic and biodegradable, and avoiding waste. Moving forward to a different chemistry based on imitation of nature, or biomimesis, must be part of that “green” future. The proposal of a sustainable chemistry goes hand-in-hand with the need to develop sustainable products, based on clean production. Imagine, then, a chemical that:
• Does not accumulate in the environment or in our bodies, • Does not present toxicity - neither to human beings nor to the environment, • Is based on renewable resources, • Minimizes the use of energy and resources, • Whose products can be reused, recycled or composted at the end of their lives, and • That produces necessary and useful products and safe jobs.
25
Based on Mestres (2006), Hacia una producción química sostenible. University of Valencia 26
Monosson, E. (2007). “Chemicals use in Africa”. Encyclopaedia of Earth
http://www.eoearth.org/article/Chemical_use_in_Africa (last accessed 19 December 2007)
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Is that a fantasy? Or can it be the reality of our future. Apart from formulating objective and general strategies, it seems necessary to answer the fundamental question of whether it is technically feasible to develop and implement green chemistry and to establish clean production systems. Numerous chemical products are already being developed by major companies according to these principles. As they also represent significant new economic opportunities, consumers and clients should urge companies to adopt widely green chemistry. Yet, it is important to guarantee that the products of green chemistry do not have adverse effects on workers’ health. It is true that many technical questions remain unsolved. Nonetheless, it is difficult to find answers when the resources allocated to research and development as well as impact assessment are not sufficient.
Box 9. Green Chemistry research Based on 12 principles, the Green Chemistry approach was developed by Doctors Paul Anastas and John Warner: 1. Prevention: It is better to prevent waste than to treat or clean up waste after it has been created; 2. Atom Economy: Synthetic methods should be designed to maximize the incorporation of all materials used in the
process into the final product; 3. Less Hazardous Chemical Syntheses: Wherever practicable, synthetic methods should be designed to use and
generate substances that possess little or no toxicity to human health and the environment; 4. Designing Safer Chemicals: Chemical products should be designed to effect their desired function while
minimizing their toxicity; 5. Safer Solvents and Auxiliaries: The use of auxiliary substances (e.g., solvents, separation agents, etc.) should
be avoided wherever possible and innocuous when used; 6. Design for Energy Efficiency: Energy requirements of chemical processes should be recognized for their
environmental and economic impacts and should be minimized. If possible, synthetic methods should be conducted at ambient temperature and pressure;
7. Use of Renewable Feedstocks: A raw material or feedstock should be renewable rather than depleting whenever technically and economically practicable;
8. Reduced Derivatives: Unnecessary derivatization (use of blocking groups, protection/deprotection, temporary modification of physical/chemical processes) should be minimized or avoided if possible, because such steps require additional reagents and can generate waste;
9. Catalysis: Catalytic reagents (as selective as possible) are superior to stoichiometric reagents; 10. Design for Degradation: Chemical products should be designed so that at the end of their useful lives they break
down into innocuous degradation products and do not persist in the environment; 11. Real-time analysis for Pollution Prevention: Analytical methodologies need to be further developed to enable
real-time, in-process monitoring and control prior to the formation of hazardous substances; and 12. Inherently Safer Chemistry for Accident Prevention: Substances and the form of a substance used in a
chemical process should be chosen to minimize the potential for chemical accidents, including releases, explosions, and fires.
Source: Anastas, P. T.; Warner, J. C. (1998) Green Chemistry: Theory and Practice, Oxford University Press: New York, p.30.
Box 10. Clean Production Cleaner Production is the continuous application of an integrated preventive environmental strategy to processes, products, and services with a view to increasing overall efficiency, and reducing risks to humans and the environment. Cleaner Production can be applied to the processes used in any industry, to products themselves and to various services provided in society (UNEP, 2001). • For production processes, Cleaner Production results from one or a combination of raw materials, water and
energy; eliminating toxic and dangerous raw materials; and reducing the quantity and toxicity of all emissions and wastes at source during the production process;
• For products, Cleaner Production aims to reduce the environmental, health and safety impacts of products over their entire life cycles, from raw materials extraction, through manufacturing and use, to the “ultimate” disposal of the product; and
• For services, Cleaner Production implies incorporating environmental concerns into designing and delivering services.
Source: UNEP. Production and Consumption Branch. “Cleaner production: key elements” http://www.uneptie.org/pc/cp/understanding_cp/home.htm#definition (last accessed 12 March 2009
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The political will to invest in innovation and research, to adopt regulatory frameworks that prioritize clean production and green chemistry incentives, and to promote capacity development for appropriate action are some of the doors that need to be unlocked. Green chemistry is the key to the door to a sustainable path forward.
3. SAFE USE OF CHEMICALS IN THE WORKPLACE
Safer management of chemicals at work: will it require major changes? Module objectives: The module aims at:
• Providing guidelines on how to identify problems and situations of chemical risk in the workplace; • Advising on prioritizing problems to be addressed through preventive action; • Advising on the preventive measures to be put in place, and the notion of “substitution principle”; • Identifying steps to ensure workers’ participation.
Learning outcomes: At the end of the session, the trainee will be familiar with:
• Sources of information about chemicals used at work; • The different states in which hazardous substances can be found throughout the production process (as primary
resources, auxiliary products, sub products, or final products), including in the case of non-intentional releases; • Interpreting the information on labels and Safety Data Sheets; • Identifying potential risks related to chemical substances in the workplace; evaluating better their consequences
for human health and the environment; • Steps to elaborate more consistent, complete and effective plans of intervention; • The notion of “substitution principle”.
PREVENTION IS THE CORNERSTONE: ENHANCING A SAFETY AND PREVENTION CULTURE
This unit will mainly address the following questions:
1. How to design a framework for intervention in the workplace? 2. Where to get useful information on chemicals to this end? 3. What are management’s and the manufacturer/supplier’s responsibilities regarding workers’ right-to-know?
The groups most exposed to chemical contamination are, logically, the people who are closer to the source. The first examples that come to mind are industry and agriculture workers. However, workers in the service sector such as hairdressers are significantly exposed as well. Thus, it is not a coincidence if the harmful health effects of many chemical products have been first discovered among workers. To prevent chemical risks, it is necessary to:
• identify the substances present in the workplace; • be aware of their risks for health and the environment; • understand both employers’ and employees’ perception of risk; • identify alternatives that bear lesser risk; and • evaluate the advantages and inconveniences that these alternatives may present from a legal, environmental,
occupational and economic perspective, before implementing them. All workplaces should implement effective safety procedures against chemical hazards, agreed jointly between employers and workers. In some countries, these agreements will be negotiated as collective bargaining agreements or health and safety agreements between management and workers. Sometimes these agreements are additional to the minimum
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obligations imposed on employers by workplace health and safety laws. However, agreements that are not part of a collective bargaining agreement experience implementation problems, as they lack legal power. Occupational health and environmental protections are two sides of the same coin. This section presents a number of steps to follow to prevent occupational and environmental risks in the workplace, related to the exposure to chemical products and substances. The final objective is to provide advice to workers’ representatives, business and industry, as well as other social actors involved in preventing adverse health and safety effects in the workplace. The main objectives are the:
• Identification of chemical risk situations and problems in the workplace; • Evaluation of the problems, in terms of priority and importance, to determine the type of preventive action; • Promotion of concrete prevention practices; • Enhancement of workers’ participation.
Source: Based on ISTAS. “Chemical risk prevention in the workplace. Guide for intervention” http://www.istas.net/web/abreenlace.asp?idenlace=1367
Preparing a Framework for “Intervention”
SITUATION ANALYSIS
Experience has shown that the level of awareness and degree of perception of the people involved are key to the success of any intervention in the workplace. Those in charge of drafting the plan of intervention must be aware of this before starting any preventive measures against chemical risk, and, if necessary, they must create the conditions that will enhance the overall awareness and degree of perception of these risks in the workplace.
PREPARE INTERVENTION
IDENTIFICATION OF EXPOSURE RISK AND CHEMICALS
Risk situations Dangerous substances Characteristics of exposure
RISK ASSESSMENT
PLAN OF INTERVENTION
Risk elimination Technical evaluation Risk control
+ PROTECTION AND EMERGENCY ACTION
FOLLOW-UP: Evaluation, efficiency and revision
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In this case, they should first identify and take into account workers’ and, importantly, management’s perceptions and attitudes about chemical risk in the workplace. If it appears that there is little concern in the workplace about chemical risk, the first actions should focus on information and sensitization through:
• Providing proof of chemical risk in the workplace; • Raising awareness on the effects of these chemical products on health and the environment; and • Identifying options to avoid and reduce risk through responsible attitudes (good practices, use of alternative
substances, among others). EVALUATION OR RAPID ASSESSMENT OF THE WORKFORCE AND MANAGEMENT’S PERCEPTIONS OF RISK
As indicated previously, the level of awareness and the degree of perception towards chemical hazards is critical to the success of any chemical risk elimination or risk reduction intervention. AWARENESS RAISING AND SENSITIZATION
Workers and employers’ sensitization to risks caused by chemical products is key for effectively preventing these risks. For the person in charge of designing the plan of intervention, it is very important to raise awareness. This training should enhance the knowledge and skills required for the sound and sustainable management of chemicals, both in the workplace and in the living environment.
Where to Get Information?
One of the biggest challenges for workers’ and trade union health and safety representatives is to obtain adequate information about chemicals used at work. There are different sources of information, which they should all explore, as a single source will often not tell everything they need to know. The most important sources of information are the labels on containers and the hazard data sheets. Other relevant sources include:
• The Union or Health and Safety Representative; • The manufacturer or supplier of the chemical, through Material Safety Data Sheets (MSDS), labels and/or direct
inquiries; • The Employer; • Higher Learning and Research Institutions; • A registrar of Chemicals (TPRI, GCLA etc); • International Trade Secretariats, e.g. IUF, ICTU; • International Chemical Secretariats, e.g. ChemSec; • Intergovernmental Organizations, Agencies and Programmes, e.g. ILO, UNEP, WHO, IFCS, UNITAR; • Secretariats of Conventions and Agreements, e.g. Stockholm, Rotterdam, Basel, Bamako, Cartagena; • Non–Governmental Organizations, e.g. IPEN, PAN Africa, WWF, PAN AP; • International Campaigns, e.g. Fair Flowers Fair Plants (FFP) programme; • Survey of the workplace and interviews/consultations of workers; • National legislation(s): see “right-to-know”.
The latter two sources are of particular relevance: • Survey of the workplace and interviews/consultations of workers: this is an important source of information,
which results from a site-visit to the different workplaces and areas and an exercise of consultation with workers. This will also provide a reference against which to compare the information given by the company.
A detailed overview of the places and sites that show a higher level of absenteeism is usually indicative of higher rates of occupational accidents and incidents and points out where the major problems may be.
�Try to get information from as many of these sources as you can, to get a full picture of
chemicals’ hazards!
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• National legislation(s): Many countries now have some kind of legislation governing communication of hazard or “right-to-know”. Under these laws, employers, manufacturers, suppliers and importers of chemicals must provide clear, detailed information about the particular chemical substance or product in question: its possible health effects, including the results of animal tests and surveys of exposed workers, and means of protecting workers from any harmful effect.
� Right to Information and Management’s responsibility: These laws make it the employer’s legal responsibility to
provide workers with as much information and training as possible on all chemical substances used. Some unions have negotiated agreements that require the union be given full information on all chemicals used in the workplace. Unfortunately, many employers do not have this information and may not know where to get it. In this case, the health and safety representative should insist that the employer obtain information from the manufacturer or the supplier of the chemical and make it available to the workers.
� Right to information and Manufacturer and Supplier’s responsibilities: If the employer cannot obtain the necessary information, a worker or the union may write directly to the manufacturer of the chemical to request the information.
Manufacturers and suppliers, in particular, are required to provide information through: LABELS
The label is the basic tool to keep the user informed on the classification of a product’s hazard and the most important safety precautions. Labels must be attached to the container, and correspond to the exact chemical that can be found in the container. It is highly recommended that chemicals be kept in their original containers. However, when a hazardous chemical has been transferred from its original shipping container, the secondary and all subsequent containers should carry the appropriate warning labels. Labels should be affixed to all containers from the production of the chemical to its disposal. International, regional, and national classification and labelling systems are already established and tested in practice:
• The United Nations Recommendations on the Transport of Dangerous Goods is widely recognized and used among the UN member states;
• The classification and labelling system of the European Union which is used beyond the EU countries; and • Several functioning national systems, such as those of Canada and USA, may also be used as models for national
systems. A proper label must clearly show the trade name; the name and the address, including telephone number, of the manufacturer, the importer or the distributor; the chemical name of the substance (in the case of a preparation, the chemical names of the hazardous components); the quantity of the contents of the package or container. Most important, it contains signs and symbols of danger, international numbers (CAS or ICSC numbers), risk phrases (Rphrases) and safety phrases (S-phrases), which are widely used in many countries from all over the world. THE GLOBALLY HARMONIZED SYSTEM OF CLASSIFICATION AND LABELLING OF CHEMICALS (GHS) It is important to mention the Globally Harmonized System of Classification and Labelling of Chemicals (GHS), which is an internationally recognized system set to replace the various classification and labelling standards used in different countries. The GHS establishes consistent criteria for classification and labelling of chemicals on a global scale. It covers all hazardous chemicals, including substances and mixtures. Compliance with the GHS is voluntary for each country. However, it is likely that countries that do not adopt the GHS will be at a disadvantage when doing business internationally. There is no definite international implementation schedule for the GHS. The United Nations are targeting its broad international adoption by 2008. Yet, different countries will require different periods to update current regulations or implement new ones.
�In accordance with the objectives and principles of the ILO Occupational Health and safety
Convention, 1981 (n. 155), and Recommendation, 1981 (n.164), Employers should make chemical safety data sheets or similar relevant information of the chemicals used at work available to workers and their representatives.
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SAFETY DATA SHEETS Safety data sheet (or SDS) is the name given to the Material Safety Data Sheet of the Globally Harmonized System of Classification and Labelling of Chemicals (GHS). Safety Data Sheets should contain identification information about the substance (composition, physical, chemical and toxicological hazards), information on specific protection and prevention measures throughout the whole process (production, storage, transport, etc.), measures to undertake in case of an accident (spillage, fire-fighting measures, etc.), as well as contact details of the supplier. Chemical safety data sheets should be available within the enterprise for every chemical substance that has been classified as hazardous. They should also be available for preparations (products) containing any hazardous substance as a component. Chemical safety data sheets are published under several names, such as:
• International chemical safety card (ICSC); • Chemical safety card; • Chemical info-sheet; • Material safety data sheet (MSDS); • Hazard data sheets (HDSs); • Chemical safety data sheets (CSDSs); • Product safety data sheet; • Health and safety data; and • Safety data sheet (SDS).
Validated data sheets on pure substances are available, for example, from the International Programme on Chemical Safety (IPCS, www.intox.org) or from national institutions such as the Canadian Centre for Occupational Safety and Health (www.ccohs.ca). These can be used by manufacturers as basic sources of information.
Box 11. Information on GHS labels The required information in the GHS labels includes:
� Symbols (hazard pictograms): Convey health, physical and environmental hazard information assigned to a GHS hazard class and category. Pictograms include the harmonized hazard symbols plus other graphic elements, such as borders, background patterns or colours to convey specific information. The symbols are similar to current EU symbols, with a few exceptions;
� Signal Words: "Danger" or "Warning" used to emphasize hazards and indicate their relative level of severity, assigned to a GHS hazard class and category. Some lower level hazard categories do not use signal words. Only one signal word corresponding to the class of the most severe hazard should be used on a label; and
� Hazard Statements: Standard phrases assigned to a hazard class and category that describe the nature of the hazard. An appropriate statement for each GHS hazard should be included on the label for products possessing more than one hazard.
Additional label elements included in the GHS are:
� Precautionary statements: measures to minimize or prevent adverse effects; � Product identifier: name or number used for a hazardous product on a label or in the SDS; supplier
identification: the name, address and telephone number should be provided on the label; and � Supplemental information.
Source: UNECE. “Globally Harmonized System of Classification and Labelling of Chemicals (GHS)” http://www.unece.org/trans/danger/publi/ghs/ghs_welcome_e.html (last accessed 14 March 3009)
�Every chemical container in the workplace, no matter how small, should have an appropriate,
understandable label.
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Examples of labels
BEING A WORKPLACE DETECTIVE: IDENTIFICATION OF EXPOSURE RISKS AND CHEMICALS
This unit will mainly address the following questions:
• How to identify “hot spots” for chemical risks and problems in the workplace? • How to accurately map out hazardous substances and materials? • How to characterize exposure to these hazards?
Text books and literature do not give all the answers about workplace risks: barely one in every 100 chemicals used at work has been systematically tested. Finding out if there is a potential risk in the workplace requires collective vigilance. That means each worker should do his/her own “detective” work. Unions have been instrumental in identifying a number of workplace illnesses, such as cancers.
�The best of information is the workforce itself, as workers know their jobs, their workmates and the
real hazards.
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Source: UNECE. “Globally Harmonized System of Classification and Labelling of Chemicals (GHS)” http://www.unece.org/trans/danger/publi/ghs/ghs_rev01/01files_e.html (last accessed 12 March 2009)
Identification of “Hot Spots”: Where are the Problems and Risks?
Workers’ exposure to chemical risk and toxic products can take place in different sections and departments on the production line. It can affect a single work post or a large number of positions. Environmental risk exposure can originate from generating solid polluted wastes, spilling or pouring dangerous substances with water through waste pipes, draining or during accidental discharges or emission of dangerous substances into the air, whether through windows, systems of ventilation or chimneys. Identification of risk situations can:
• Be limited to the place of work or can refer to a concrete working area (department, number of different tasks for the production process, etc.); and
• Be extended to the whole organization or business to identify all possible risk situations.
Box 12. Safety Data Sheets contents according to the Globally Harmonised System of classification The information in the SDS should be presented using the following 16 headings in the order given below: 1. Identification: identifies the substance or mixture and provides the name of the supplier, recommended uses and the
contact details for the supplier including an emergency contact; 2. Hazard identification: describes the hazards of the substance or mixture and the appropriate warning information -
signal word, hazard statement(s) and precautionary statement(s)- associated with these hazards; 3. Composition/information on ingredients: identifies the ingredient(s) in the product. This includes the impurities and
stabilizing additives that are themselves classified and contribute to the classification of the substance as a whole. This section may also be used to provide information on complex substances;
4. First-aid measures: This section describes the initial care that can be given by any untrained individual, without the use of sophisticated equipment and without a wide selection of medications available. If medical attention is required, the instructions should state so, as well as the level of urgency. It may be useful to provide information on the immediate effects, by route of exposure, and indicate the immediate treatment, followed by possible delayed effects with specific medical surveillance required;
5. Fire-fighting measures: covers the requirements for fighting a fire caused by the substance or mixture, or arising in its vicinity;
6. Accidental release measures: recommends the appropriate response to spills, leaks, or releases in order to prevent or minimize the adverse effects on persons, property and the environment. Distinguish between responses for large and small spills where the spill volume is a significant factor in the hazard. The procedures for containment and recovery may indicate that different practices are required;
7. Handling and storage: provides guidance on safe handling practices that minimize the potential hazards to people, property and the environment from the substance or mixture. Emphasizes precautions that are appropriate to the intended use and to the unique properties of the substance or mixture;
8. Exposure controls/personal protection: for the purposes of this document “exposure control” means the full range of specific protection and prevention measures to be taken during use in order to
minimize worker and environmental exposure; 9. Physical and chemical properties: describes the empirical data of the substance or mixture (if possible) in this
section; 10. Stability and reactivity: describes the reactivity hazards of the substance or mixture in this section. Provides specific
test data for the substance or mixture as a whole, where available. However, the information may also be based on general data for the class or family of chemical if such data adequately represent the anticipated hazard of the substance or mixture;
11. Toxicological information: used primarily by medical professionals, occupational health and safety professionals and toxicologists, it provides a concise but complete and comprehensible description of the various toxicological (health) effects. The available data used to identify those effects should also be provided;
12. Ecological information: provides information to evaluate the environmental impact of the substance or mixture if it were released into the environment. This information can assist in handling spills, and evaluating waste treatment practices and should clearly indicate species, media, units, test duration and test conditions;
13. Disposal considerations: provides information for proper disposal, recycling or reclamation of the substance or mixture and/or its container, in order to assist in the determination of safe and environmentally preferred waste
management options, consistent with the requirements of the national competent authority
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To identify “hot spots”, workers need to look at the company’s operations in a different way. Rather than focusing on the end-product, they need to look in details at the storage, handling, and use of chemicals throughout the production process. To this end, they can walk through the entire process and develop a flowchart that represent the complete production process, or the different tasks and sections that take place at work. This enables the identification of different places where chemical exposure may occur. Depending on the type of company (sector, size, number of workers, etc.) there are several places and tasks that involve chemicals and result in the generation of chemical waste, dangerous spills, air emissions, etc. In addition, actions and tasks that are carried out in the workplace frequently require the use of several different chemical products, each of which can contain several substances, resulting in “multiple exposure”.
Mapping Out the Hazardous Substances and Materials
It is recommended to draft and update a comprehensive list of all the products that are used regularly in the workplace. These may be in the form of solid or liquid waste, gas emissions or poured liquids made up of a mix of products, as indicated in section one. This step involves:
• Systematically identifying all chemical substances that are stored and used in the factory; and • Creating a structured database than can be used to identify and make improvements on a continuous basis.
This list can be elaborated using the information provided by workers, as well as from the labels on the packages and containers and the safety data sheets (SDS). (Read more in Where to get information?). This should provide information about their composition, their physico-chemical properties and their toxicity to human health and the environment. In drafting this list, workers and their representatives should be aware that hazardous substances can be:
• Found in different natural states: solid, liquid or gaseous; • Involved in the production processes as primary resources, auxiliary products, intermediate products, sub products
and/or non-intentional releases, or even, the final product; and • Used or generated regularly or sporadically as a result of cleaning tasks, maintenance tests, etc.
The inventory should include the following information:
• The products used at different stages of the production process; • Their compositions, especially the active ingredients they contain; • The dangers for the environment; • The potential health risks; and • Gender specific health risks.
Identification of Exposure Characteristics
After identifying where the problems are, what the dangerous substances are, and what damage they entail, it is necessary to further define the magnitude and severity of risk in each situation. The hazard potential of a substance (toxicological and ecotoxicological hazard) depends on its physico-chemical properties. To determine the risks associated with its use, the circumstances and conditions of use that make the risk possible, i.e., the risk factors, must be known. Eventually, regardless of the conditions of usage and the prevention measures taken some chemicals should still be banned. These substances belong to black list of chemicals, and their elimination is a priority. The risk factors, i.e. the conditions of use and handling, include:
• Work organization and rhythm of work. Experience shows that these are the two conditions that most determine chemical risk, as overexposure and unnecessary exposure are the cause of many accidents;
• Physical activity accelerates the breathing rhythm and therefore enables a larger amount of toxics to penetrate into the organism (inhalation is the major route of entry);
�Magnitude and Severity of a Risk = Hazard + Exposure
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• Working hours: Prolonging the number of working hours increases the duration of exposure to contaminants; • Micro-clime: Working conditions such as temperature, humidity and ventilation can increase exposure. High
temperature fosters the evaporation of volatile substances. High humidity can foster the presence of hydrosoluble substances in the air;
• Specific individual conditions: Younger or older workers, pregnant or breastfeeding women, workers with weak or sensitive health, etc are likely to be more sensitive;
• Lack of information among workers about the products they use or lack of adequate training about chemical risk; and
• Whether there are or not effective measures to control occupational and environmental exposure. The best way to identify each risk situation is to undertake regular visits and inspections through the different stages and posts of production, as well as to talk regularly to affected workers. This information will be summarized in a flow chart indicating the types of risk and their causes at each stage of the production process, detailing the post and level in the production process concerned.
Box 13. The “dirty five” group! The common chemical groups that causes major health risks are:
• DUSTS, FUMES AND GASES - Dust may be just a nuisance, but it can present serious risks. The potential danger depends on the type of material in the dust, and on the amount and the size of the particles. Asbestos falls into this category. Exposure to metal fumes can cause damage to the body. “Metal fume fever” is a known health effect of inhaling metal fumes, especially if they contain zinc. It usually appears on the day following that of exposure. Gases do not necessarily have a warning odour at a dangerous concentration level. The odour may be detected only at very high concentrations in the air. Gases may have an irritating effect, or they may enter the blood circulation and cause internal damage. Sulphur oxides, nitrogen oxides, chlorine and ammonia are toxic gases widely used in industry.
• SOLVENTS - Most solvents are liquid organic chemicals. They are used because of their ability to dissolve other substances, particularly fat and grease, which are insoluble in water. Many of them evaporate rapidly at ambient temperatures. They are often flammable. Many solvents have a narcotic effect and may cause dizziness, headache, reduced comprehension or tiredness. Some solvents are very hazardous to the liver, kidneys, bone marrow or nervous system. Benzene, carbon tetrachloride and carbon disulphide belong to the category of solvents that should be substituted with less dangerous ones.
• METALS - Metals can enter the body in the form of dust and fumes (in grinding or welding) or even through the skin. Lead is used in various industries: battery, glass and mining sectors, for example. Mercury is present in many pesticides and pickling baths. Nickel is present mixed with other metals in various alloys. Chromium compounds are widely used in industry, and may cause birth defects if mothers are exposed to them during pregnancy.
• ACIDS AND BASES - Strong acids and bases are mostly used as water solutions. They are corrosive to human tissue. Working with acids or bases can give rise to mists that have the same corrosive properties as the solutions Serious damage can result when treating metal pieces in an acid bath (with phosphoric acid for example).
• PESTICIDES - Pesticides are intended to destroy or control pests of all kind. They are used in industry, for example, to impregnate wood, and in agriculture to control insects, weed, fungi, and rats. There are many different types of pesticide compounds or mixtures. Insecticides are divided into the following broad groups, among them organophosphorous compounds (often acutely poisonous to both insects and humans), organochlorine compounds and carbamates (insecticides and fungicides).
Source: ILO. “Training Modules on Chemical Safety: Introduction to Safety in the use of chemicals” http://www.ilo.org/public/english/protection/safework/cis/products/safetytm/introduc.htm (last accessed 2 March 2009)
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What to do?
IS YOUR JOB PUTTING YOU AT RISK? QUALITATIVE RISK ASSESSMENT
This unit will mainly address the following issues:
1. What are the potential risks in the workplace? 2. What is a qualitative risk assessment?
Risk assessment aims at obtaining the necessary information to make an appropriate decision on whether and how preventive measures should be adopted. Technical assessments are not always necessary to evaluate, act, eliminate or control a risk. Actually, on many occasions, the risk is so obvious and its solution so evident that any prior formal evaluation is simply a waste of time and money. In this section it is not expected that a technical evaluation of the risks will be carried out, nor taking samples and developing measurements of the contaminants or other technical actions. On the contrary, it is proposed that the importance of the identified risks along with the need to act on them be evaluated from available documentation and the information collected during the visits and the talks/interviews undertaken with workers. This method is called qualitative assessment. It will be useful to analyse the information collected until then, based on:
• Hazardous properties of substances (toxicity, etc.); • Exposure characteristics: level, type, duration; • Conditions of use and factors of risk; • Record of inconveniences or illnesses related to exposure to chemical products; • Existence of wastes, emissions or non control of spillage; and • Workers’ opinions on the risk.
Among the different qualitative models available to evaluate risk, it is proposed to use the Column Model, which is considered as one of the easiest and the handiest. Based on the R-phrases (see annex 1-B), the Column Model permits to
IDENTIFICATION OF RISK SITUATIONS: A good way to proceed is to organize the collection of information according to the following steps:
1. Divide the physical space or productive process into smaller units and sections of analysis. Sort them into a diagram or map
2. Identify the processes and tasks where chemicals are used or simply present. 3. Identify the processes or tasks that generate emissions, spills or waste by-products of chemical
substances. 4. Collect the information on a sheet including all the products present in the production process, whether they
are dangerous or not, and all the resulting products and wastes.
IDENTIFICATION OF HAZARDOUS SUBSTANCES: 1. Organize information collection keeping in mind the particular problem to solve: to avoid the possible harm
that chemical substances present in the workplace can cause. 2. Remember that chemical substances can be present in the workplace, either because they are produced or
used there, or are waste products that result from nonintentional releases. 3. To know the existing risks in each situation or task, all products must be listed, relevant information must be
collected and structured, and should include: � The name of the product or mix; � The active ingredients that compose it; � Human security and safety risks; and
� Environmental risks. IDENTIFICATION OF CHARACTERISTICS OF EXPOSURE:
1. Collect and organize information in a way that clearly identifies the production process: tasks, associated risks, etc.
2. Make a brief description of each risk, taking into account the information on the products and substances, and the information about related reasons and factors of risk.
3. Try to establish a relationship between risks and their causes.
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classify each substance according to different levels of risk. In case of doubt, the immediate higher level of classification should be systematically selected. Box 14. The Column Model In case of doubt, the immediate higher level of classification should be systematically selected. Risks: level/type
Acute health hazards (single affection)
Chronic health hazards (repeated affection)
Environmental Hazards
Fire and explosion hazards
Exposure potential
Hazards caused by procedure
Very high R26, R27, R28, R32
R45, R49 R50, R51, R53, R54, R55, R56, R57, R58, R59
R2, R3,R12, R17
Gases; � Liquids which evaporate at room temperature; � Dust producing solids; � Aerosols.
Open processing; � Possibility of direct skin contact; � Application on large area.
High R23, R24, R25, R29, R31, R32, R42, R43
R33, R40, R60, R61, R68
R1, R4, R5, R6, R7, R8, R9, R11, R15, R16, R18, R19, R30, R44
Liquids which evaporate between 30 and 50°C
Medium R20, R21, R22, R34, R41, R64,
R63 R52, R53 R10 Liquids which evaporate between 50 and 150°C
Closed processing but exposure possibilities e.g. when filling sampling or cleaning
Low R36, R37, R38, R65, R66, R67
Others (no R-Phrase associate, but hazardous
Hardly flammable substances/ preparations (55-100°C)
Liquids which evaporate at more than 150°C
Negligible Harmless substances by experience (e.g. sugar, water, paraffin and similar)
Inflammable or very hardly flammable substances/ preparations (100°C)
Liquids which evaporate at more than 200°C
Tightly closed equipment; � Closed equipment, with exhaust facilities at points of emission.
Source: Based on the classification provided by Berufsgenossenschaftliches Institut für Arbeitssicherheit (BIA) www.hvbg.de/bia What to do?
1. Check the hazard potential of the existing chemical substances 2. Carry out regular inspections with standard checklists for particular chemicals and chemical processes; 3. Investigate workers’ complaints; 4. Use accident and sickness records; 5. Survey regularly workers’ health; 6. Monitor environmental and biological parameters; 7. Investigate the causes of accidents and their prevention; and 8. Develop a workplace chemical register.
GET PRIORITIES RIGHT! PLAN OF INTERVENTION
This unit will mainly address the following questions:
• What are the principles for operational control of chemical hazards? • What control measures should be implemented for safe storage, disposal, and treatment of chemical waste? • What control measures are needed to guarantee safe transport of chemicals?
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Controlling the Hazard: Principles for Operational Control
The general objective in the control of hazards relating to chemicals in the workplace is to eliminate risks or reduce the potential hazard to the lowest possible level in relation to their contact with workers or the environment, as well as to minimize the possibility of a fire or an explosion.
1. Ideally, the best means of preventing diseases, injuries, fires and explosions caused by chemicals would be to rid the working environment of such chemicals, eliminating risks through application of the precautionary principle. No severely hazardous chemical should be authorized in the workplace, regardless of whether or not a substitute exists;
2. When strict prevention is not possible, the risk may be reduced or eliminated through substitution. However, no substitute is 100% safe.
3. When prevention and substitution are not feasible, risks should be reduced via control mechanisms that include the following options:
� Engineering controls – enclosing, isolation, silencer, etc.; � Management controls – warnings, e.g. do not smoke while spraying; � Personal Protective Equipment (PPE) – e.g. gloves, goggles, coveralls, apron, masks, etc; and � Personal and environmental hygiene.
SUBSTITUTION OF HAZARDOUS CHEMICALS OR PROCESSES WITH LESS HAZARDOUS ONES
Extremely hazardous chemicals should be removed from the workplace even where substitutes are not available. Elimination of hazardous substances can take place in two different ways, through: • Substitution for other substances that are less hazardous; or • Modification of the production process. However, care must be taken to obtain all available information on proposed alternative chemicals. Indeed, substitutes may turn out to be just as hazardous as or even more hazardous than the materials they replace. As noted in the graphic, below, there are a number of direct and indirect benefits associated with actions that are taken to reduce and eliminate hazardous substances. Box 15. Benefits associated with reducing or eliminating hazardous substances in the workplace Direct Benefits Indirect Benefits
• Reduce occupational health risks; • Reduce damage (illnesses,
accidents) and absenteeism; • Reduce environmental risks; • Improve security;
• Reduce costs related to risks.
• Improve the image of the enterprise/company; • Improve labour relations; • Motivate the creation of some
posts/sections/departments within the enterprise such as occupational and health departments, environmental department, etc.;
• Improve on productivity and profitability of the company through decrease in medical expenses, absenteeism, presenteeism, etc.
Presenteeism is defined as lost productivity that occurs when employees come to work but perform below par due to any kind of illness or emotional problems (anxiety, stress), based on Paul Hemp, Presenteeism: At Work--But Out of It – Harvard Business Review HBR. Source: Based on ISTAS. “Chemical risk prevention in the workplace. Guide for intervention” http://www.istas.net/web/abreenlace.asp?idenlace=1367
ENGINEERING CONTROLS AND VENTILATION
If a chemical hazard cannot be eliminated from the workplace by resorting to substitution, then the next best solution is to physically enclose or isolate the hazard to prevent it from coming into contact with either workers or the environment. This is known as total enclosure or containment of a process. However, with this option, the source of the hazard should be monitored first; if this is not possible then the pathway should be monitored, before the worker is. For example, open tanks from where chemical vapours can escape into the workplace air can be replaced with closed tanks with inlet and outlet ports for filling and emptying. Ventilation systems are a means of removing contaminated air from the workplace. However, attention should be paid to the filters used, as it can easily happen that chemical vapours are released into the environment, polluting the water and soil which workers and other come into contact with in many other ways. Proper calibration of spray equipment is another example of engineering control.
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MANAGEMENT CONTROLS
Management control measures to control occupational and environmental exposure should only be considered when there is no possibility to eliminate the risk. Different management control mechanism can be applied to reduce exposure to chemicals:
• Restricted entries: Only those directly involved with a chemical process should be exposed to any chemical hazard. Maintenance workers, electricians, cleaners or any other workers should do their work when the chemical hazard is not present.
• Special attention to high-risk groups: The risk to high-risk groups, e.g. maintenance workers, pregnant and nursing women, spray teams, young and health sensitive workers, is often ignored or seriously underestimated when planning chemical control measures. These workers may be more highly exposed because of the nature of their duties, biological and physiological factors or state of health. Specific provisions for the protection of high-risk workers must be included in any chemical safety procedure.
• Job rotation: In certain circumstances, the reduction in the duration or the frequency of exposure of workers is achieved by job rotation. However, it is simply not acceptable to expose more workers less often to significantly high levels as an alternative to reducing exposure levels.
• Observing re-entry intervals in sprayed places: Management should make sure it has all information on recommended re-entry intervals for all chemical and these are displayed at entry points of all sprayed places. Management must educate workers on the importance of observing re-entry intervals.
USE OF PERSONAL PROTECTIVE EQUIPMENT AND PERSONAL HYGIENE
Whereas engineering controls place a barrier around a hazardous process or chemical, personal protective equipment is often used to create a "barrier" around a worker, thus preventing his/her exposure to chemicals. The use of personal protective equipment (PPE) should only come as additional protection after the methods outlined above (substitution and engineering controls) have first been considered and implemented. Personal protective equipment is rated as the least effective method of protection and is often uncomfortable or difficult to work with. Personal protective equipment against chemicals includes:
• Face shields, goggles and safety glasses; • Gloves; • Rubber boots; • Plastic or rubber overalls and aprons; • Hard hats; • Respirators; and • Dust masks.
A personal protective equipment programme requires the following steps and resources:
• The correct equipment - e.g. a respirator designed to protect against dust is useless if the hazardous chemical is present as a gas; moreover many solvents can rapidly penetrate natural rubber gloves;
• A thorough training programme for workers who are required to use the equipment, with follow-up training at regular intervals;
• Tests to ensure that equipment fits correctly; such tests are particularly important for face masks and respirators; • A regular equipment maintenance and storage programme. This includes regular cleaning of equipment,
inspection to ensure that it is operating correctly and regular replacement of items such as gloves or disposable parts such as respirator filters (which should be replaced at regular time intervals rather than only when they have become clogged); and
• A personal set of equipment for each worker, and a secure and clean place in which to store it.
In some situations, the use of personal protective equipment cannot be avoided. This applies particularly to eye goggles, face shields, boots and hard hats. Because these items are designed to protect the worker against accidents and unexpected exposures, they must be worn at all times. Personal hygiene is very important to protect the body against anything harmful remaining on it for long periods, especially since it can be absorbed through the skin. Examples of actions that can be taken are: to keep fingernails clean and short,
�Personal protective equipment should be appropriate to the hazard. Great care should be taken to
fit the equipment to the worker. Equipment should not be perceived as a nuisance or a trouble to develop tasks, otherwise it will not be used.
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not to carry contaminated items such as dirty rags or tools in the pockets of personal clothing, and to remove and wash separately any contaminated item of personal protective clothing daily. At the same time, it is equally important to avoid inhaling or ingesting small, even minute, quantities of chemicals because of their harmful effects on health. This concern reinforces the importance of drinking, eating or smoking away from possible exposure areas.
TECHNICAL EVALUATION: OCCUPATIONAL AND ENVIRONMENTAL SURVEILLANCE
Since elimination of chemical risks is a long-term task, technical evaluations on the occupational and environmental risks should be undertaken. To develop this evaluation the assistance of experts (doctors and others) is necessary to carry out medical examinations on workers (blood tests, urine tests, etc). The same applies to environmental tests. There are two types of technical evaluation: environmental monitoring (ecotoxicological monitoring) to measure the level of contaminants in the environment (air, water, soil, fauna and flora) and biological monitoring of individual workers to test for degree of exposure, whether dermal, respiratory, via ingestion, etc. The results of these samples should be compared with the threshold limit value (TLV) and Time Weighted Average (TWA) - average exposure on the basis of a 8h/day, 40h/week work schedule - to see whether or not a worker’s exposure is under or above what is recommended, and to act accordingly. As noted in an earlier section, TLVs are good tools for practical action in case the result exceeds recommended levels. However, while being under the TLV is important, it is not a full guarantee of safety. Even when the results of environmental monitoring controls are under 50% of the reference threshold limit value (called as Level of Action), preventive measures such as the revision of the proper functioning of the systems implemented, realization of new controls, job rotation, among others, may still be required to avoid possible contamination.
Control Measures For The Storage, Disposal, Waste And Treatment
CONTROL MEASURES FOR THE STORAGE OF HAZARDOUS CHEMICALS
Safety Data Sheets from the manufacturers or suppliers of chemicals should give specific instructions on the storage of each chemical. These instructions must be strictly respected, as storage requirements vary according to the nature of the chemical. Incorrect storage can have disastrous results, e.g. fire, explosion or release of toxic chemicals. Several factors need to be taken into account in reviewing the Safety Data Sheets:
• Certain chemicals require must not be stored together (need for isolation), given the possibility that vapours or leaks may, if they intermingle, lead to an explosion.
Box 16. Use of PPE Pesticide spraying For some jobs, such as pesticide spraying by hand, no other means of protection is possible. In this case, protective clothing, gloves and respirator masks must be worn. Wood dust Wood dust consists of tiny particles of wood produced during processing and handling of wood, chipboard, hardboard etc. It can be harmful to health and can explode with disastrous results. Exposure has been associated with the following health problems: skin disorders; obstruction in the nose; a type of asthma; and a rare type of nasal cancer. It is a sub product, the result of an industrial process, and cannot be substituted. Thus, the only way of reducing risk from wood dust is to:
• Provide personal protective equipment, such as eye protection, overalls and gloves.
• Make sure it is suitable and kept in good order. Launder overalls and aprons regularly.
• Make good washing facilities available, with hot and cold water, soap and towels and encourage a high standard of personal hygiene.
• Provide vacuum cleaning equipment to remove dust from clothing, where this is a problem. Prevent the use of compressed airlines.
Make sure workers are adequately instructed, trained and supervised. This is essential if they are to understand the precautions necessary, and their duties and responsibilities in applying them. Source: Based on the UK Health and Safety Executive Committee http://www.hse.gov.uk/woodworking/dust.htm
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• The chemicals must be kept away from food, drink and animal feed, and stored at a temperature below their flash points. The storage temperature must obviously be below the auto-ignition temperature. Chemicals with flash points below 34°C are especially dangerous.
• SDSs often specify a "well-ventilated" storeroom for particular chemicals, and it is essential to comply with this requirement. More specific guidance on the amount of ventilation required can be obtained from the manufacturers of the chemicals, and the actual levels of ventilation in the workplace can be checked by an industrial hygienist or ventilation engineer.
• Chemicals may react with the material from which containers are made. It is thus important to have information about the type of container used, which should be specified on the SDS. This is especially important if chemicals may be transferred from one container to another. There may be additional requirements, such as pressure relief valves, which are relevant to the storage of particular chemicals.
• The type of flooring should also be specified, as it must be resistant to, and not potentially reactive with, the chemical being stored.
• The low walls or embankments (referred to as dykes or bunding) that are constructed around the storage area should be sufficiently high to contain any leaks that may occur from storage containers, as well as any water or foam that may be sprayed in the event of a fire.
• Alarms also are recommended in areas where potentially dangerous chemicals are stored in order to give early warning of releases of those chemicals.
DISPOSAL CONTROL MEASURES: WASTE AND TREATMENT OF CHEMICALS
Given that enormous volumes of waste are generated in the production and use of chemicals, waste disposal is a key issue in health and environmental protection. As with protection of the workplace, a hierarchy of controls should be applied when dealing with chemical waste, as follows:
• Reduction of waste at the source; • Segregation of waste; • Recovery and recycling; • Waste exchange; • Incineration; • Immobilization of intractable wastes; • Landfill storage; • Discharge into sewer; and • Other forms of temporary or final storage.
The volume and toxicity of hazardous waste can be reduced by modifying a process or by improving process controls. CONTROL MEASURES FOR SPILLAGE
Many spills can be prevented by thorough planning of work, provision of suitable equipment, regular preventive maintenance and good training of workers. Any spillage that do happen should be thoroughly investigated and remedial action taken to prevent their recurrence. Employers should ensure that they have the necessary plans and equipment to deal with spillages, that the workforce and their representatives have been consulted about all such planning, and that the necessary training is carried out regularly. When a spillage occurs, suitable precautions must first be taken to protect workers from the dangers of the chemical (fumes, burns, etc.) before steps are taken to deal with the spillage itself. Some general measures that may apply include the following:
• Use self-contained breathing apparatus and full protective clothing, when applicable; • Remove ignition sources; • Do not smoke; • Evacuate the area, if necessary at one’s own initiative, as every single worker has the right to remove
himself/herself from imminent danger; • Collect leaking liquid in sealable containers; • Prevent liquid from spreading or contaminating other areas, vegetation, waterways and cargo, with a barrier of the
most suitable available material, e.g. soil or sand; • In some cases (e.g. hydrazine), a foam can be applied to slow down vaporization; • Absorb spills in sand, soil, moist sawdust or other inert material and transfer them to a suitable container; then
remove to a safe place, and dispose of them in accordance with local regulations; • Sweep up solid products, and transfer to a suitable container; and
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• Depending on the chemical, do not allow run-off into sewers: it may cause an explosion, kill wildlife or affect water supplies.
Control Measures for the Transport of Chemicals
Transport is necessary for products to reach consumers. The transport and storage of dangerous chemicals and goods has increased, as commerce has expanded, due to technical and production advances. The export of used toys, motor vehicles and electronics equipment can be a route through which hazardous chemicals are transported from developed to developing countries. These products may contain highly hazardous chemicals such as lead, cadmium and phthalates. The hazardous properties of products or chemicals should be clearly stated so that people at all stages of the transport chain are aware of them. This information should always track the goods so that people can recognize the risks, avoid accidental mishandling, and have the right kind of the personal protection at their disposal in case of leakage. Empty containers and packages of dangerous goods can present the same hazards as the chemical substance or product that they contained. It is therefore important to also treat them as dangerous goods. Major accidents cause extensive damage, but so can smaller ones. It is forgotten easily that small amounts of oil, gasoline, battery acids and refrigerator fluids are released into the environment daily. Even small but frequent wastes from ships, households, cars or agriculture increase the contamination of the environment.
Box 17. Different waste treatments
• Recycling: The best-known form of recycling is the recovery of useful fractions for reuse. These processes are usually carried out by specialist recovery operators off-site and involve recovery of materials such as oils and solvents, as well as other valuable materials, such as silver in photographic waste.
• Waste exchanges: A considerable amount of waste is suitable for exchange. The aim of the exchange is to put potential users of waste materials in touch with industries that produce the waste, and vice versa. Waste exchanges reduce the volume of wastes requiring landfill or incineration.
• Incineration: This process involves burning wastes in special high-temperature (1,200°C) incinerators. Incineration effectively destroys many organic wastes. Additionally, the energy in solvent and fuel waste can be exploited in the process. However, inorganic chemicals such as plastics are likely to cause pollution problems when incinerated, as dangerous dioxins and furans may be formed if some organic materials are incinerated improperly, e.g., at very low temperatures.
• Encapsulation: The waste is sealed within a stable, inert material to prevent contact with the environment and prevent movement (migration). If the encapsulating jacket were broken, the waste could leach away. Encapsulation is better suited to those wastes that, while posing a handling hazard, are relatively inert once buried (e.g. asbestos).
• Landfill: Landfills are used for most residual solids or pastes because they are of smaller volume and less likely to migrate through the soil. A number of solid hazardous wastes require the higher degree of safety afforded by secure landfill, whereby waste is poured into small cells lined with an impermeable clay or synthetic material, and subsequently buried under a layer of soil. However, there are potential problems of infiltration by rainwater and it is not always easy to ensure permanent maintenance of the cell if the company relocates its operations or closes its business.
• Disposal of less hazardous waste to the sewer: This is generally not recommended. Improper disposal to the sewer can
disrupt the biological treatment of sewage and represent a hazard at sewer outfalls. In addition, toxic chemicals (e.g. heavy metals) may accumulate in the sewage sludge and create hazards when they are disposed of.
• Storage of intractable wastes: A large volume of hazardous waste is currently stored -usually in steel drums on industrial sites, awaiting the development of satisfactory disposal methods - because it is too toxic to be legally disposed into air, water or landfill sites. Most drums are stored in the open, and many contain corrosive materials. There is an added risk of hazard from fires, structural damage and vandalism of such toxic waste stores. It is likely that some of these drums will corrode and leak. In some countries, such stores must be registered with authorities who, in turn, have a duty to inspect them.
Source: United Nations Environment Programme (UNEP) / International Labour Organization (ILO) / World Health Organization (WHO). “Users’ Manual for the International Programme On Chemical Safety (IPCS)”., Health And Safety Guides http://www.inchem.org/documents/hsg/hsg/hsgguide.htm (last accessed 2 March 2009)
�Dangerous goods can be transported without causing unnecessary hazards if handled properly
and with care.
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Recommendations and instructions for the handling, storage and transport of dangerous goods must be clear and unambiguous to avoid harmful or dangerous circumstances. Under normal conditions, transport of dangerous goods does not pose a greater danger than the transport of any other goods, provided the transport chain respects the existing recommendations and laws, and are aware of the type of hazards that the cargo bears. There is always a risk of spillage during the transport of hazardous goods. When incompatible substances mix with each other there is a possibility of a chemical reaction, which can produce enough heat to cause fire or explosion and can release dangerous gases. For example, toxic nitrous oxides are formed when ammonium nitrate (in fertilizers) decomposes in a fire. Another example involves the toxic gases that fume off when a spillage of concentrated sulphuric acid is absorbed in sawdust. Spillages are possible in the following situations:
• Goods not properly packaged; • Handling without reference to the contents: loading, unloading, etc. in the event of missing or incomplete labelling; • Fire, either when the load or the vehicle is burning; • Collision or capsize; and • Defects in tightness or incomplete closing of valves and connections.
The United Nations published a book collecting the work of the Committee of Experts: UN Recommendations on the Transport of Dangerous Goods. This has been largely incorporated into the Globally Harmonised System of classification and labelling which covers the processes of production, storage and transport. What to do? To plan action taking into account the aforementioned, you can use a guide as a chart like annex 2 card 5 which will help you to structure the following information and data to:
� Identify clearly the risk situation and establish the priority to act on it; � Order priorities from higher to lower level risk; � Establish objectives, such as to eliminate risk, to inform workers, or to establish control measures; � Get information about the measures and procedures of action that are more adequate. Consult technical officers
and workers; � Analyse information and select the actions; and � Submit the flowchart of actions to the working centre with an estimated budget for their consideration.
SAFE CHEMICALS – SAFE PRODUCTS GUIDELINES TO ENFORCE THE “SUBSTITUTION PRINCIPLE”
This unit will mainly address the following questions:
• How can the “substitution principle” successfully be implemented? • How to identify safer substitutes for chemicals? • How to evaluate the economic, environmental and social viability of potential substitutes?
One of the most efficient and effective way to reduce chemical hazards is the application of the “substitution principle”. This can be achieved either by substituting:
• The substance, for an another without affecting the productive process; • Equipment and procedures without affecting the productive process; or by • An auxiliary substance or primary resource that modifies the productive process.
For any of the three cases of substitution of substances or processes, necessary steps are as follows:
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Source: Based on ISTAS. “Guide for the substitution of dangerous substances in the workplace. Practical guidelines for intervention” http://www.istas.net/web/abreenlace.asp?idenlace=2428
Identification of the Problem
The first steps involve identifying the problem. It is important to remember, though, that identification of the problem is not the only action required in dealing with the risk to eliminate. It is also crucial to know the circumstances and factors that help assess how necessary it is to implement substitution. For that process, it is necessary to determine how substitution would be achieved, and why it is needed.
Information about Processes and Substances
As part of these first steps, in compiling information it will be needed to put together a “basic card” of the workplace and the activity, to know what hazards and risks exist in the workplace, and which ones are being targeted for elimination. It is suggested to compile basic information with regard to the identification of the substance or product based on a number of questions on the tasks normally developed in the workplace. Workers also need as well to know the functions of the chemicals, so that they can answer questions such as “why is it used” and “how is it used in the process”. Sometimes, chemicals are used but workers might not know why. In the course of the exercise, workers might find that there is a lot of information needed that is not available. The labels and the safety data sheet (SDS) should provide basic information to identify adequately the substances and products used. Where SDSs are not directly available, in principle the employer has to provide them to the workers. Alternatively, a search
IDENTIFICATION OF THE PROBLEM
INFORMATION ABOUT PROCESSES AND SUBSTANCES
ESTABLISHMENT OF SUBSTITUTION CRITERIA
RESEARCH/STUDY OF ALTERNATIVES
EVALUATION OF ALTERNATIVES
PILOT EXPERIENCE
IMPLEMENTATION OF THE SUBSTITUTION
REVISION AND RISK EVALUATION
Follow-up and control phase
If it works If it does not work
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can be conducted for guides and leaflets on the equipment and products used at work. In pursing the information, workers may find that the equipment and products are often not used properly. Questions to raise, among others:
• “What tasks do I perform? • Why do I carry them out in such a way? • Which risks do they entail? • Could I do it differently? • Why do I use this product? • Which effects it has? • Could I use another product? • Could I use different tools?”
Establishment of Substitution Criteria
Substitution criteria are established in two different ways, by identifying:
• Those chemical substances that are priorities for substitution among all the chemicals that are being used; and • The alternative substance which would be most appropriate.
It is important to bear in mind a key principle in approaching substitution:
Taking into account this definition, establishing objective criteria to search for alternatives is critical. The following table presents actions and strategies that should be followed as part of the substitution process. Criteria for the election of alternative products Information available The first criteria to decide for one or another product or substance should be the
information accessible: composition, intrinsic hazard, use and applications, safety card, etc. Essential information on a potential alternative substance must be at least as complete, in terms of type and amount, as information on the substance to be substituted.
Avoidance of halogenated substances All components that incorporate bromine, fluorine or chlorine have characteristics involving high persistence in the environment, and a high degree of toxicity in human beings
Preference of mechanic, physic or biological options instead of chemical substances
The alternatives based on mechanical, physical or biological options normally present much lower levels of risk than those related to chemical substances
Avoidance of most hazardous substances and products
All chemical substances present intrinsic hazards. When selecting substitutes, those substances that cause major harm for human health and the environment have to be always avoided. The absence of information on potential harmful effects does not mean the substance is safe.
Preference for easy and compatible products The action of any chemical substance or product is based on an “active principle” which determines its properties: cleans, disinfects, protects, etc. Normally this “active principle” characterizes the substance, or, in limited situations it characterizes a
�In accordance with the objectives and principles of the Occupational Safety and Health
Convention, 1981 (n. 155), and Recommendation,1981 (n.164), employers should make available to workers and their representatives chemical safety data sheets or similar relevant information of the chemicals used at work.
�When searching for an alternative, do not think of the process of substitution as if it were
completely free of danger. Instead, it should be viewed as fulfilling an objective focused on eliminating a risk previously established. Be careful: make sure that the alternative presented does not just shift an equivalent or higher risk to another part of the process. This would only perpetuate the problem, and perhaps even make it more difficult to remedy.
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combination of different substances. In all cases, it helps get information that is relevant to individual, specific substances or products.
Source: Based on ISTAS. “Guide for the substitution of dangerous substances in the workplace. Practical guidelines for intervention” http://www.istas.net/web/abreenlace.asp?idenlace=2428
Research/Studies and the Evaluation of Alternatives
At this stage, an initial, informed and objective evaluation needs to be developed, which will eventually help take sound decisions in a quick and independent manner. The elements to take into account in the evaluation are the following:
• Impacts on human and environmental health; • Technical viability; • Economic and costs viability; • Social impacts.
In pursuing that objective, summarizing in a matrix all the information collected on the alternative substance and the substance to replace can be useful for comparison purposes. The following table provides a good structure for carrying out this comparative analysis. Informative matrix on the effects of selected chemicals Exposure routes Acute effects Chronic effects Environment
Irritant To be specified To be specified
Contact (skin)
Ingestion (digestive tract)
Inhalation (respiratory tract)
Skin Eyes Respiratory system
Carcinogenic Reproductive system Nervous system Liver/kidneys Respiratory system Endocrine disrupter
Persistent Bioaccumulative Toxicity Water polluter Air polluter Soil polluter Damages ozone layer Volatile components Toxic waste
Substance CAS N.
*Perchloroethyl ene (PER) 127-18-4
√ √ √ √ √ √ Possible carcinogenic Affects nervous system and kidneys
Eco-toxic, water pollutant, volatile compound
** Trementine essence (turpentine) 8006-64-2
√ √ √ √ √ √ Water pollutant, volatile compound
** D-limoneno 5989-27-5
√ √ √ √ √ √ Water pollutant, volatile compound
* Substance to be substituted ** Possible alternatives Source: Based on ISTAS. “Guide for the substitution of dangerous substances in the workplace. Practical guidelines for intervention” http://www.istas.net/web/abreenlace.asp?idenlace=2428
It is also important to underline some working methodologies such as “Alternatives Assessment Framework” that is designed to evaluate and identify environmentally and socially preferable alternatives. “Alternatives” encompass production processes, chemicals, materials, products, economic systems (such as transportation systems), and functions, as well as eliminating the need for a current activity or the function of a product.
Pilot Experience
Before introducing an alternative, it is highly advisable to develop a pilot project that uses this specific substance at some point in the production process for the purpose of testing it. At this stage, how the alternative is presented will be extremely important. The attitude and perception of directly affected workers and other people are key to obtain as much information and feedback as possible from the pilot experience, and to ensure that the experience works properly and successfully. The results of the pilot experience must be properly evaluated and taken into account in order to assess the viability of the proposed alternative on an industrial scale.
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Implementation of the Substitution
Once the previous steps have been successfully covered, the alternative of substitution considered is more likely to be viable.
Revision and Risk Evaluation
The introduction of a safer substance in replacement of another one does not guarantee the total elimination of risk. For this reason, it is necessary to carry out regular evaluations that consider the new existing risks, as well as to set-up any necessary preventive measures to initiate effectively a process of substitution. Workers have an important role in the promotion of substitutes.
KEEP AN EYE ON WHAT IS HAPPENING! HEALTH AND ENVIRONMENTAL SURVEILLANCE AND FOLLOW-UP
This unit will address the issue of surveillance and follow-up.
Surveillance and Follow-Up: Evaluation, Efficiency and Revision
There must be a follow-up of the measures of prevention and control of chemical risk, included in the national legal framework, to make sure that there is effective and efficient implementation. Once chemicals risks have been evaluated and the prevention plan has been elaborated, a variety of potential exposure parameters must be selected for further monitoring purposes. This is necessary to determine whether the risk has been completely eliminated, or because of peculiarities and specificities of the workers exposed (e.g. pregnant women, the need to use personal protective equipment (PPE), etc.). Undertaking health surveillance of various areas of risks which, in principle, have been controlled and eliminated, is necessary to make sure that the objective of risk elimination has been achieved. In addition, periodic evaluation of potential health and environmental impacts must be undertaken, and become necessary as a result of:
• Modifications of the production mass, materials or process; • Record of new cases of occupational diseases or impacts on the environment; • Accidents or incidents; • Figures on occupational or environmental health which illustrate risk; • Changes in the knowledge of risk; • Legislative changes; or • New methods or technologies to control risk; • Staff turnover or new management staff; and • Change in microclimate or buildings.
What to do? Identify the situations of risk and where risk is located;
• Specify measures to adopt actions proposed and agreed with the working centre; • Indicate starting and closing dates for specific actions; • Undertake a follow-up process; and • Where results are not satisfactory, study measures and actions to improve it.
WATCH OUT! RISK NEVER SLEEPS: EMERGENCY AND FIRST-AID PROCEDURES
Good safety organization, ventilation and engineering controls, adequate provision of information on the health hazards of chemicals, and training of workers can help reduce and control chemical exposure in the workplace. Nevertheless, as
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poisonings may still occur, workers must be trained and properly equipped so that emergency situations can be handled satisfactorily. Chemicals that are stored together may accidentally mix during an emergency, forming a new substance with thoroughly different characteristics. The plant chemist or industrial hygienist should be able to provide workers and trade unions representatives with advice about the appropriate storage of chemicals, in order to keep non-compatible chemical substances away from each other.
The Emergency Plan
It is essential to have an emergency plan in every workplace. The plan should lay down the following procedures and information:
• The evacuation of workers, including a system of accounting for the workers once outside the building; • Methods of notifying outside assistance such as medical, rescue, fire or environmental protection specialists, as
necessary; • The role of various plant officials during an emergency; • The role of selected workers; and • The location and procedures for the use and maintenance of all emergency equipment in the plant.
Everyone in the plant should be kept informed of the emergency plan and be able to understand it in detail. The plan should describe clear and unobstructed emergency exits, a functioning and frequently tested alarm system, and training in evacuation for all workers. It should also detail procedures for the immediate evacuation of disabled workers who may need assistance in reaching emergency exits. There should be emergency assembly points outside the plant so that each worker can be accounted for after evacuation. These predetermined meeting areas should be safe in case of escalation of the situation. The emergency plan should outline the structure of the first-aid organization within the plant, as well as procedures to obtain more specialized medical care when and as necessary. The role of all plant personnel (including workers, supervisors and managers) during an emergency situation should be described. The location of all emergency and first-aid equipment, including emergency showers, eye-wash stations, first-aid kits and stretchers, should also be mapped out. The plan should address the organization of the internal capability to fight small fires within the plant. As with first aid, the role of all plant personnel in a fire emergency must be described, even if it only details the procedures for rapid evacuation. The location of all fire-fighting equipment such as sand buckets, hoses and extinguishers, as well as automatic fire-fighting systems, should be described with specific guidance as to who should fight a chemical fire, when and how. A chemical leak or spill can have disastrous consequences when the situation is not tackled rapidly. The emergency plan should specify the staff who will be involved in controlling the leak or managing the spill. Again, any specific material or equipment must be described. Emergency plans should be developed in conjunction with local medical, fire, law enforcement and civil defence authorities, as well as neighbouring plants, to ensure better coordination among these actors and a more effective implementation.
� 1. Every workplace should have an emergency plan. 2. The plan should cover emergency exits and an alarm system for evacuation. 3. The plan should outline the duties and responsibilities for first aid and fire fighting within the
organization.
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4. INTRODUCTION to BAT/BEP
4.1 DEFINITIONS (i) "Best available techniques" means the most effective and advanced stage in the development of activities
and their methods of operation which indicate the practical suitability of particular techniques for providing in principle the basis for release limitations designed to prevent and, where that is not practicable, generally to reduce releases of toxic chemicals e.g. those listed in Part I of Annex C of the Stockholm Convention and their impact on the environment as a whole.
(ii) “Techniques” includes both the technology used and the way in which the installation is designed, built, maintained, operated and decommissioned;
(iii) “Available” techniques means those techniques that are accessible to the operator and that are developed on a scale that allows implementation in the relevant industrial sector, under economically and technically viable conditions, taking into consideration the costs and advantages.
(iv) “Best” means most effective in achieving a high general level of protection of the environment as a whole.
(v) "Best environmental practices" means the application of the most appropriate combination of environmental control measures and strategies.
The concept of best available techniques does not prescribe any specific technique or technology, but takes into account the technical characteristics of the installation concerned, its geographical location and the local environmental conditions. Appropriate control techniques to reduce releases of the toxic chemicals particularly listed in Part I of the Stockholm Convention are in general the same. In determining best available techniques, special consideration should be given generally or in specific cases, to the following factors:
a) General considerations:
(vi) The nature, effects and mass of the releases concerned: techniques may vary depending on source size;
(vii) The commissioning dates for new or existing installations;
(viii) The time needed to introduce the best available technique;
(ix) The consumption and nature of raw materials used in the process and its energy efficiency;
(x) The need to prevent or reduce to a minimum the overall impact of the releases to the environment and the risks to it;
(xi) The need to prevent accidents and to minimize their consequences for the environment;
(xii) The need to ensure occupational health and safety at workplaces;
(xiii) Comparable processes, facilities or methods of operation which have been tried with success on an industrial scale;
(xiv) Technological advances and changes in scientific knowledge and understanding.
b) General release reduction measures:
When considering proposals to construct new facilities or significantly modify existing facilities using processes that release chemicals listed in this Annex, priority consideration should be given to alternative processes, techniques or practices that have similar usefulness but which avoid the formation and release of such chemicals. In cases where such facilities will be constructed or significantly modified, the following reduction measures could also be considered in determining best available techniques:
(i) Use of improved methods for flue-gas cleaning such as thermal or catalytic oxidation, dust precipitation, or adsorption;
(ii) Treatment of residuals, wastewater, wastes and sewage sludge by, for example, thermal treatment or rendering them inert or chemical processes that detoxify them;
(iii) Process changes that lead to the reduction or elimination of releases, such as moving to closed systems;
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(iv) Modification of process designs to improve combustion and prevent formation of toxic chemicals, through the control of parameters such as incineration temperature or residence time.
4.2 CONSIDERATION OF ALTERNATIVES IN THE APPLICATION OF BEST AVAILABLE TECHNIQUES
The Stockholm Convention addresses the “consideration of alternatives” with specific reference to best available techniques as follows:
“When considering proposals to construct new facilities or significantly modify existing facilities using processes that release chemicals listed in Annex C, priority consideration should be given to alternative processes, techniques or practices that have similar usefulness but which avoid the formation and release of such chemicals.”27
4.2.1 An Approach to Consideration of Alternatives
When considering proposals to construct new facilities or significantly modify existing facilities consideration of alternatives that avoid the formation and release of toxic chemicals should be made. In doing this, a comparison of the proposed process, the available alternatives and the applicable legislation using what might be termed a “checklist approach”, keeping in mind the overall sustainable development context and taking fully into account environmental, health, safety and socio-economic factors, should be made.
The following are elements of such an approach:
Review the proposed new facility in the context of sustainable development: Carry out a review of both the originally proposed new facility and of possible alternatives in the context of the country’s plans for sustainable development. The purpose of such a review is to enable decision makers to understand better the proposed facility and its intended usefulness in relation to social, economic and environmental considerations, and its potential contribution to sustainable development.
Identify possible and available alternatives: Identify available alternative processes, techniques or practices that have similar usefulness but which avoid the formation and release of toxic chemicals. Available guidance comprising options for those processes, techniques and practices should be taken into account (for example, guidance from the Basel Convention, the World Health Organization (WHO), the Food and Agriculture Organization of the United Nations (FAO), other intergovernmental bodies and governments).
Undertake a comparative evaluation of both the proposed and identified possible and available alternatives: After possible and available alternatives have been identified, decision makers should undertake comparative evaluations of the various options, namely the originally proposed new facility and all possible alternatives that may be under consideration. In some cases, and for some kinds of facilities, it may be most appropriate for this comparative evaluation to be done by local or district authorities. However, in many cases, it may be more appropriate, from a sustainable development perspective, for the comparative evaluation to be made at some other strategic or policy level.
Priority consideration: A proposed alternative should be given priority consideration over other options, including the originally proposed facility, if, based on the comparative evaluation described in subsection 3 above, available alternative is determined to:
• Avoid the formation and release of toxic chemicals such as those listed in Annex C;
• Have similar usefulness;
• Fit comparatively well within a country’s sustainable development plans, taking into account effective integration of social, economic, environmental, health and safety factors.
27 See Stockholm Convention, Annex C, Part V, section B, subparagraph (b).
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4.2.2 Other Important Considerations
Health, safety and environmental considerations: The overall goal should be to protect human health and the environment from toxic chemicals. In carrying out comparative evaluations of originally proposed facilities and possible and available alternatives health, safety and environmental considerations should be taken into account.
Health, safety and environmental impacts of proposed alternatives should be compared with the corresponding impacts of the originally proposed facility. The outcome of this comparison should constitute an important component in the consideration of “similar usefulness” and in a determination of practicality and feasibility.
Social and economic considerations: Social economic considerations associated with possible control measures should also be considered. However, it is also a starting point for a useful list of social and economic considerations and criteria that can be used by authorities in carrying out comparative evaluations of originally proposed facilities and identifying possible and available alternatives. The following general criteria may be used:
• Technical feasibility;
• Costs, including environmental and health cost;
• Cost efficiency;
• Efficacy (infrastructural capacity, including availability of well-trained staff);
• Risk;
• Availability;
• Accessibility;
• Operator friendliness (ease of use);
• Positive or negative impacts on society, including health (public, environmental and occupational health); agriculture (including aquaculture and forestry); local and traditional techniques and/or knowledge; biodiversity; economic aspects; movement towards sustainable development; and social costs.
In many cases, a proposed new facility may have the potential to contribute to a country’s economic development and poverty reduction plans. Proper implementation of the sound chemicals management should not significantly interfere with this potential. Rather, if properly implemented, the sound chemicals management should contribute positively to sustainable development and poverty reduction.
In some cases, appropriate alternatives require less expenditure on imported capital goods, relying rather on locally available labour sources and building on local knowledge. Such alternatives fit well into a country’s sustainable development plans; and provide usefulness that is as good as or better than the originally proposed facility.
Finally, proper implementation of sound chemicals management can reduce the burdens of disease and health deficits that undermine efforts aimed at sustainable development and poverty reduction.
4.2.3 Best Available Techniques And Best Environmental Practices: Guidance, Principles And Cross-Cutting Considerations
General principles and approaches The following is indicative of some of these general environmental management principles and approaches, that should be considered:
Sustainable development: “Development that meets the needs of the present without compromising the ability of future generations to meet their own needs.”28
Sustainable consumption: “The use of services and related products which respond to basic needs and bring a better quality of life while minimizing the use of natural resources and toxic materials as well as the emissions of waste and pollutants over the life cycle of the service or product so as not to jeopardize the needs of future generations.”29
28 World Commission on Environment and Development. 1987. www.un.org/documents/ga/res/42/ares42-187.htm. 29 UNEP (United Nations Environment Programme). 1994. Oslo Symposium: Sustainable Consumption. Oslo, Norway,
January 1994. www.iisd.org/susprod/principles.htm.
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Development and implementation of environmental management systems: “A structured approach for determining, implementing and reviewing environmental policy through the use of a system which includes organizational structure, responsibilities, practices, procedures, processes and resources.”30
Use of science, technology and indigenous knowledge to inform environmental decisions: “Increase the use of scientific knowledge and technology and increase the beneficial use of local and indigenous knowledge in a manner respectful of the holders of that knowledge and consistent with national law;” and “Establish partnerships between scientific, public and private institutions, including by integrating the advice of scientists into decision-making bodies to ensure a greater role for science, technology, development and engineering sectors.”31
Precautionary approach: “In order to protect the environment, the precautionary approach shall be widely applied by States according to their capabilities. Where there are threats of serious or irreversible damage, lack of full scientific certainty shall not be used as a reason for postponing cost-effective measures to prevent environmental degradation.”32
Internalizing environmental costs and polluter pays: “National authorities should endeavour to promote the internalization of environmental costs and the use of economic instruments, taking into account the approach that the polluter should, in principle, bear the cost of pollution, with due regard to the public interest and without distorting international trade and investment.”33
Pollution prevention: “The use of processes, practices, materials, products or energy that avoid or minimize the creation of pollutants and waste, and reduce overall risk to human health or the environment.”34
Integrated pollution prevention and control: “This principle aims to achieve integrated prevention and control of pollution arising from large-scale industrial activities. It lays down measures designed to prevent or, where that is not practicable, to reduce emissions in the air, water and land from these activities, including measures concerning waste, in order to achieve a high level of protection of the environment taken as a whole.”35
Co-benefits of controlling other pollutants: For instance, pollution prevention and control of other contaminants may also contribute to the reduction and elimination of chemicals listed in Annex C.
Cleaner production: “The continuous application of an integrated preventive environmental strategy to processes, products and services to increase overall efficiency and reduce risks to humans and the environment. Cleaner production can be applied to the processes used in any industry, to products themselves and to various services provided in society.”36
Life cycle analysis: “A system-oriented approach estimating the environmental inventories (i.e. waste generation, emissions and discharges) and energy and resource usage associated with a product, process or operation throughout all stages of the life cycle.”37
Life cycle management: “An integrated concept for managing the total life cycle of goods and services towards more sustainable production and consumption, building on the existing procedural and analytical environmental assessment tools and integrating economic, social and environmental aspects.”38
Virtual elimination: “The ultimate reduction of the quantity or concentration of the toxic substance in an emission, effluent, or waste released to the environment below a specified level of quantification. The ‘level of quantification’
30
UNEP (United Nations Environment Programme). 2002. Environmental Impact Assessment Training Resource Manual.
Page 558. www.iaia.org/Non_Members/EIA/ManualContents/Vol1_EIA_Manual.pdf. 31 UN DESA (United Nations Department of Economic and Social Affairs) 2002 Plan of Implementation of the World
Summit on Sustainable Development, page 50.
http://www.un.org/esa/sustdev/documents/WSSD_POI_PD/English/WSSD_PlanImpl.pdf 32 UNEP (United Nations Environment Programme). 1992. Rio Declaration on Environment and Development. Principle
15. Rio de Janeiro, Brazil, 1992. www.unep.org/Documents/Default.asp?DocumentID=78&ArticleID=1163. 33 Preamble to Stockholm Convention and Principle 16 of the Rio Declaration on Environment and Development. 34 Environment Canada. 1995. Pollution Prevention – A Federal Strategy for Action.
www.ec.gc.ca/cppic/aboutp2/en/glossary.cfm. 35 European Commission. 1996. Integrated Pollution Prevention and Control Directive. 96/61/EC.
europa.eu.int/smartapi/cgi/sga_doc?smartapi!celexapi!prod!CELEXnumdoc&lg=EN&numdoc=31996L0061&model=gu
ichet. 36 UNEPTIE. www.uneptie.org/pc/cp/understanding_cp/home.htm. 37 European Environment Agency. glossary.eea.eu.int/EEAGlossary. 38 UNEPTIE. www.uneptie.org/pc/sustain/reports/lcini/lc-initiative-barcelona-workshop.pdf.
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means, in respect of a substance, the lowest concentration that can be accurately measured using sensitive but routine sampling and analytical methods.”39
Community Right to Know: “In the field of environment, improved access to information and public participation in decision-making enhance the quality and the implementation of decisions, contribute to public awareness of environmental issues, give the public the opportunity to express its concerns and enable public authorities to take due account of such concerns.”40
4.2.4 Chemicals listed in Annex C: Formation mechanisms
Formation of chemicals listed in Annex C: An overview: Polychlorinated dibenzo-p-dioxins (PCDD), polychlorinated dibenzofurans (PCDF), polychlorinated biphenyls (PCB) and hexachlorobenzene (HCB) are unintentionally formed in industrial-chemical processes, such as chemical manufacture, and thermal processes, such as waste incineration. PCDD/PCDF are the only by-product persistent organic pollutants whose mechanism of formation has been studied extensively in combustion-related processes and to a lesser extent in non-combustion-related chemical processes; even so, the mechanisms and exact formation conditions are not fully resolved. It is clear that the predominant mechanism or pathway can vary from process to process so that different factors become controlling and there is no universal controlling factor.
There is far less information as to the formation of PCB and HCB, especially in combustion processes. Since there are similarities in the structure and occurrence of PCDD/PCDF, PCB and HCB, it is usually assumed that, with the exception of oxygen-containing species, those parameters and factors that favour formation of PCDD/PCDF also generate PCB and HCB.
On the other hand, in some industrial processes HCB is formed to a greater extent than PCDD/PCDF or PCB.
Formation of PCDD/PCDF
Thermal processes41: Carbon, oxygen, hydrogen and chlorine, whether in elemental, organic or inorganic form, are needed. At some point in the synthesis process, whether present in a precursor or generated by a chemical reaction, the carbon must assume an aromatic structure.
There are two main pathways by which these compounds can be synthesized: from precursors such as chlorinated phenols or de novo from carbonaceous structures in fly ash, activated carbon, soot or smaller molecule products of incomplete combustion. Under conditions of poor combustion, PCDD/PCDF can be formed in the burning process itself.
The mechanism associated with this synthesis can be homogeneous (molecules react all in the gas phase or all in the solid phase) or heterogeneous (involving reactions between gas phase molecules and surfaces).
PCDD/PCDF can also be destroyed when incinerated at sufficient temperature with adequate residence time and mixing of combustion gases and waste or fuel feed. Good combustion practices include management of the “3 Ts” – time of residence, temperature and turbulence, and sufficient excess oxygen to allow complete oxidation. Use of a fast temperature quench and other known processes are necessary to prevent reformation.
Variables known to impact the thermal formation of PCDD/PCDF include:
• Technology: PCDD/PCDF formation can occur either in poor combustion or in poorly managed post-combustion chambers and air pollution control devices. Combustion techniques vary from the very simple and very poor, such as open burning, to the very complex and greatly improved, such as incineration using best available techniques;
• Temperature: PCDD/PCDF formation in the post-combustion zone or air pollution control devices has been reported to range between 200 °C and 650 °C; the range of greatest formation is generally agreed to be 200 – 450 °C, with a maximum of about 300 °C;
• Metals: Copper, iron, zinc, aluminium, chromium and manganese are known to catalyse PCDD/PCDF formation, chlorination and dechlorination;
39 Environment Canada. 1999. Canadian Environmental Protection Act, 1999. Section 65.
www.ec.gc.ca/CEPARegistry/the_act/. 40
Aarhus Convention on Access to Information, Public Participation in Decision Making and Access to Justice in
Environmental Matters, United Nations Economic Commission for Europe, www.unece.org/env/pp
41 PCDD/PCDF may also be introduced as contaminants in raw materials or wastes and may therefore appear in processes
in which PCDD/PCDF formation does not occur.
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• Sulphur and nitrogen: Sulphur and some nitrogen-containing chemicals inhibit the formation of PCDD/PCDF, but may give rise to other unintended products;
• Chlorine must be present in organic, inorganic or elemental form. Its presence in fly ash or in the elemental form in the gas phase may be especially important;
• PCB are also precursors for the formation of PCDF.
Industrial-chemical processes: As with thermal processes, carbon, hydrogen, oxygen and chlorine are needed. PCDD/PCDF formation in chemical processes is thought to be favoured by one or more of the following conditions:
• Elevated temperatures (> 150 °C);
• Alkaline conditions;
• Metal catalysts;
• Ultraviolet (UV) radiation or other radical starters.
In the manufacture of chlorine-containing chemicals, the propensity for PCDD/PCDF formation has been reported as follows:
Chlorophenols > chlorobenzenes > chlorinated aliphatics > chlorinated inorganics
4.3 WASTE MANAGEMENT CONSIDERATIONS
4.3.1 Introduction
The importance of waste management to the environment and health: Sound waste management is an important element in the protection of human health and the protection of the environment. It also helps to avoid the loss of resources. Careless landfilling may pollute water bodies; burning of waste on landfills or in inappropriate incinerators or open burning can release high levels of chemicals listed in Annex C and other toxic substances such as polycyclic aromatic hydrocarbons, heavy metals and particulate matter. For this reason a holistic approach to improving the waste management system will have positive effects in a number of areas.
Waste management consists of many different areas of intervention. As a first step waste prevention and reduction can help reduce the generation of waste, and its hazard potential, to a minimum. In industrial processes the development and use of low-waste and non-waste technologies have had a positive effect in decreasing the amount of waste requiring treatment. Greater emphasis on producer responsibility may also help to solve or at least reduce waste management problems. (see figure 1)
4.3.2 Definitions
The Basel Convention on the Control of Transboundary Movements of Hazardous Wastes and Their Disposal gives the following definition for wastes in general:
“Wastes are substances or objects which are disposed of or are intended to be disposed of or are required to be disposed of by the provisions of national law.”
The Basel Convention defines “disposal” as operations which may or may not lead to the possibility of “resource recovery, recycling, reclamation, direct re-use or alternative uses.”
Annex I of the Basel Convention lists 45 categories of hazardous wastes subject to transboundary movement requiring control, unless they do not fall into any of the following categories, the characteristics of which are listed in Annex III of the Basel Convention:
• Explosives;
• Flammable liquids;
• Flammable solids;
• Substances or wastes liable to spontaneous combustion;
• Substances or wastes which, in contact with water, emit flammable gases;
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Figure 1: Waste management hierarchy
• Oxidizing substances;
• Organic peroxides;
• Poisonous (acute) substances;
• Infectious substances;
• Corrosives;
• Substances that liberate toxic gases in contact with air or water;
• Toxic (delayed or chronic) substances;
• Ecotoxic substances;
• Substances capable, by any means, after disposal, of yielding another material, e.g. leachate, which possesses any of the characteristics listed above.
Waste Management Hierarchy
PREVENT Avoid waste generation
REDUCE Less raw material input
REUSE Maximize time to end of life
RECYCLE Reprocessing of waste materials
RECOVERY OF ENERGY AND MINERALS Use alternative fuels or materials e.g. in cement kilns
Incineration with recovery of metals and energy
INCINERATION AND NEUTRALISATION Destruction of pollutants and toxics
RESPONSIBLE DISPOSAL Permanent safe landfill
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4.3.3 The Importance of Developing National Waste Management Strategies
Waste management influences all parts of society and of its economy. It concerns local, regional and national authorities; it requires a legal base, a financial mechanism, and a great deal of coordination between citizens and authorities at all levels. Furthermore, good waste management is not feasible without a minimal level of investment. To ensure a coherent waste management system, all the actions at different levels should follow a commonly agreed strategy.
4.3.4 Some Principles to be Applied
• The source reduction principle, “by which the generation of waste should be minimized in terms of its quantity and its potential to cause pollution. This may be achieved by using appropriate plant and process designs”;
• The integrated life cycle principle, “by which substances and products should be designed and managed such that minimum environmental impact is caused during their generation, use, recovery and disposal”.
• “Prevent and minimize waste and maximize reuse, recycling and use of environmentally friendly alternative materials, with the participation of government authorities, and all stakeholders, in order to minimize adverse effects on the environment and improve resource efficiency, with financial, technical and other assistance for developing countries. This would include actions at all levels to:
(a) Develop waste management systems with the highest priority placed on waste prevention and reduction, reuse and recycling, and environmentally sound disposal facilities, including technology to recapture the energy contained in waste, and encourage small-scale waste-recycling initiatives that support urban and rural waste management and provide income-generating opportunities with international support for developing countries;
(b) Promote waste prevention and reduction by encouraging production of reusable consumer goods and biodegradable products and developing the infrastructure required.”
4.3.5 The Importance of Public Education
Successful implementation of a general waste management plan needs the assistance of different actors: consumers, authorities, waste management operators. All these stakeholders have to be informed about coherent waste management and have to be convinced to contribute to its successful implementation. There is a clear need for awareness building at all levels: for example, consumers should be informed about strategies for avoiding waste and the advantages of using recycling opportunities; and information about the health hazards of open burning of waste and promotion of better alternatives are necessary if this way of disposal is to be reduced and eventually stopped.
4.3.6 Influencing Production and Products
All industrial or artisanal products will at some point become waste. Hence, the quality and especially the technical lifetime of products have a crucial impact on the quantities of waste that have to be eliminated.
National authorities are limited in their ability to directly prescribe the general life cycle quality of products and encourage the production of long-life products. There are however several quite efficient indirect ways to influence these aspects of production.
In many countries public procurement is an important part of the overall market. By defining quality standards and minimum requirements, public procurement allows the quality of the products offered to be influenced. “Sustainable procurement is a process whereby organizations meet their needs for goods, services, works and utilities in a way that achieves value for money on a whole life basis in terms of generating benefits to society and the economy, whilst minimizing damage to the environment”
In general it is useful to avoid unnecessary packaging, to promote durable and reusable products, and to utilize materials and product designs that avoid toxicity and other hazard characteristics and that enable end-of-life remanufacture, material recovery and recycling.
Labelling is another powerful instrument: it enables the consumers to select products based on environmental performance, price and quality, thus directing their demand towards goods produced with respect for the principles of sustainable development.
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4.3.7 Product Warranties
Products become wastes at the end of their life. If the use of a product is limited by careless design or production, this may lead to an unnecessarily short technical lifetime. Electronic appliances or tyres of low quality may become waste after a comparatively short period of use, thereby increasing the amount of waste. One possible way of influencing quality is by legally defining a minimum period of warranty for products.
4.3.8 Encourage Companies to Use Environmental Management Systems
The use of environmental management systems (for example those developed by the International Standards Organization and the European Union Eco-Management and Audit Scheme, or EMAS) leads to better knowledge about industrial processes and their influence on the environment. This may also help to reduce the amount of waste and its hazardous characteristics. The responsible management of products and processes from an environmental point of view can stimulate greater awareness throughout a company, improve corporate credibility and reputation, enhance business development opportunities and facilitate dialogue and partnership with key stakeholders.
4.3.9 Producer Responsibility
Producers and other stakeholders have responsibilities that can be established through approaches such as product stewardship. In some cases it may be useful to oblige producers to take back certain end-of-life products and to assure their environmentally sound treatment.
4.4 SOURCE REDUCTION AS A PRIORITY
In general, a society should give careful consideration to the full range of waste management options and considerations before reaching a decision to make a large-scale investment in the construction of any new incinerator, a new sanitary landfill, mechanical or biological treatment, or other similar investments, or to retrofit an existing facility for these purposes.
The first priority among waste management options is source reduction – minimization of the quantity of waste, alongside the reduction of its toxicity and other hazard characteristics. This is a responsibility shared by all sectors of society. One measure of success is the percentage of discards that can be diverted from landfills and incinerators, but this should always be considered in the context of total waste generated.
In some situations, the decision to construct a new large-scale waste treatment facility can undermine efforts at waste reduction and waste-derived resource recovery. Those who invest in these new facilities will often face pressures to assure sufficient incoming waste in order to recover their investments. When this happens, the new facility can sometimes serve as a counterforce and as a disincentive to effective waste reduction efforts. Therefore, any such consideration should take place in the framework of holistic waste management policies.
4.4.1 Collection
Households usually keep waste to be discarded in designated containers. These may be metal or plastic dustbins or plastic and paper bags. In large buildings and apartment blocks, centralized containers are sometimes provided into which occupants place their waste. In most developed countries, it is usual for household waste to be collected from premises on a regular basis since food waste, in particular, decays rapidly. In cities and urban areas, waste is collected for disposal in specially designated vehicles fitted with compaction equipment to increase the payload that can be transported, often over significant distances, to sanitary landfill sites. In large conurbations, studies show that transferring the collected waste to railway containers for transport to a landfill site is economically viable; large barges are also used for transport. In some instances, waste is baled to facilitate mechanical handling.
Even though there exist quite efficient mechanical sorting systems for mixed waste, source separation and collection of recyclable goods is in many cases cheaper and will provide cleaner products for recycling. This is particularly true when, without source separation, paper and cardboard would be mixed up with wet waste from the kitchen, or when vegetable waste, designed to be composted or fermented, is at risk of being mixed with hazardous waste from small industries.
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4.4.2 Recycling
Generally a large proportion of municipal solid waste can be composted, reused or recycled. In several industrial countries more than 50% of municipal solid waste is recycled. Some regions achieve even higher recycling rates. Zero waste concept means designing and managing products and processes to reduce the volume and the toxicity of waste and materials, conserve and recover all resources and not to burn or bury them.
The sound disposal of mixed waste is in most cases more expensive than source reduction through the use of long-life products, repairing goods and efficient recycling. The possibilities of composting, reuse and recycling have to be examined and developed taking into account the composition of the waste, the existing collection and recycling systems and the economic possibilities
As an example, the recycling of paper and cardboard, metals and glass in many cases creates positive revenue or is at least cheaper than the transportation and elimination of these materials together with other wastes. Similarly, collection and recycling of polyethylene terephthalate (PET) bottles or other plastic containers can produce a feedstock for the plastic recycling industry.
In many developing countries, waste-derived resources can provide important raw materials for small-scale resource recovery and remanufacturing activities. These small-scale activities can be encouraged. When this is done, efforts should also be made to promote improvements in the health and safety of this sector, which in many countries is presently an informal sector.
The collection of recyclable goods may be done by source separation followed by collection of the recyclable goods by either public authorities or private companies. In many cases the informal sector has also built up quite efficient structures for the collection of those wastes. The use and even the reinforcement of existing structures may have economic and social advantages, and should therefore be taken into account when developing or adapting waste management.
4.4.3 Final Disposal
Even with good results in prevention of waste and with ambitious goals for recycling, some waste remains for disposal. The quantity of waste, its composition and hazardous characteristics, and the technical and economic possibilities for its disposal, are factors that have to be taken into account in choosing the final disposal method.
If the mixed waste contains a large percentage of vegetable waste, the possibilities for composting or anaerobic digestion should be examined. In some cases the waste consists predominantly of vegetable material, dust and sand, and composting of the waste after sorting out some other fractions (e.g. plastics) may be a viable option. The quality and use of the produced compost has to be evaluated.
Biological treatment or mechanical biological treatment of waste are options when the mixed waste contains, besides biodegradable material, a larger proportion of plastics, metals and other waste fractions. Mechanical biological treatment processes incorporate mechanical sorting and separation of the waste stream to separate the biodegradable materials, which are sent to a biological process, from the non-biodegradable materials. The mechanical process can be configured to further separate the non-biodegradable materials into fractions that can be recycled. The recovery of combustible parts of waste is also possible. This combustible fraction, also called waste-derived fuel, will in most cases be polluted by heavy metals and will contain more chlorine than normal fuels. For this reason, such products of waste management can only be used as fuel in installations with air pollution control equipment and careful disposal of ashes. The products of the biological treatment may be used as composts if the quality is sufficient, or can be landfilled.
4.4.4 Landfill
In many countries household waste has always been disposed of by landfilling. Significant changes in the composition of waste (e.g. more plastics), and the increasing quantities requiring disposal, led to designated areas of land being set aside as local waste disposal sites.
In a landfill, the waste is deposited in layers in prepared cells and compacted to decrease its volume. It is then covered, at least daily, with a suitable soil-like material to deter vermin, flies, birds and other scavengers and to prevent injuries from sharps. Many wastes, especially hazardous wastes, should only be disposed of in specially engineered landfills.
The putrescible fraction of waste undergoes aerobic and anaerobic processes. Landfill gas, a mixture of methane and carbon dioxide, is produced, and other organic compounds are formed. Many of these are soluble in water and become dissolved in any surplus moisture in the landfill site to produce a liquid mixture termed leachate. Leachate can be highly
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polluting, and it is necessary to prevent it from mixing with groundwater and surface water. The treatment of leachate and the safe disposal or even use of landfill gas is components of an environmentally sound waste management policy. In any case it are necessary to prevent leachate migration since it can continue to produce landfill gas away from a landfill site.
Landfill is by far the most commonly practiced waste disposal method in the majority of countries. As a result of serious environmental and health problems experienced with historic and abandoned dump sites and the very high costs associated with clean-up measures at contaminated sites, many countries have introduced the specially engineered landfill concept, whereby the wastes are only consigned to sites selected for their containment properties. They may be natural, or augmented by or provided directly by liners, the overall engineering being such as to ensure as far as possible the isolation of wastes from the environment. Such landfills are considered a final resort option only to be used after every effort has been made to reduce, mitigate or eliminate the hazards posed by such wastes.
4.4.5 Incineration
In some countries with high population density and a lack of suitable areas for landfills, incineration of waste has become the main way for the treatment and disposal of the not recyclable waste over the last 50 years. As there are many combustible components in municipal solid waste, surplus heat can be produced. Pathogenic germs and organochemical constituents in waste can be destroyed almost completely. Because household waste contains a large variety of materials, including those that are not combustible, incinerators need to be rugged and versatile to cope with a highly variable feedstock both in terms of waste composition and calorific value. Traditionally, furnaces are based on either the chain or rocking grate principle or to a lesser extent a rotary kiln. For sewage sludge and for industrial wastes fluidized bed combustion is used. To ensure high combustion efficiency the temperature range at which the furnace is operated and burns waste, the time during which the waste reaches and is maintained at furnace temperature and turbulence within the furnace chamber all need to be strictly controlled. The so-called “3 Ts principle” – temperature, time and turbulence in the presence of sufficient oxygen - are the basic requirements for good combustion.
In order to avoid gaseous or particulate emissions, incinerators have to be equipped with efficient flue gas cleaning systems, which may in many cases include catalytic converters or addition of activated carbon to the flue gas and scrubbers. If water from scrubbers is discharged, it has to be treated. Fly ash from electrostatic precipitators and residues from air pollution equipment almost certainly contain significant amounts of chemicals listed in Annex C of the Convention, so these wastes have to be disposed of in a controlled way.
The need for reliable control of the parameters of combustion, the requirements of high-tech flue gas cleaning systems and the investment necessary for energy recovery (boilers, turbines, electrical generators) may explain why incinerators are highly developed, efficient but also rather expensive technology. Smaller installations exist, but in order to achieve economies of scale, in most cases at least 100,000 tons of waste per year are needed.
Over the last years some new methods for combustion of the non-recyclable components of municipal solid waste have been developed. In some cases the waste is first crushed or milled and then burnt in a specially designed plant. This offers the possibilities to use degasification at lower temperatures or to treat with very low or non oxygen as a first step (known as pyrolysis).and to omit oxygen excess as a first step. The resulting gas is then burnt – eventually after cleaning - at high temperatures in a second step. This high-temperature step allows vitrification of the combustion residues and offers some possibilities for controlled destruction of waste contaminated with chemicals listed in Annex C. Particular care must be taken with this processes that products of incomplete combustion are not released into the environment.
4.5 CO-BENEFITS OF BEST AVAILABLE TECHNIQUES FOR CHEMICALS LISTED IN ANNEX C
4.5.1 General Considerations
The application of best available techniques for chemicals listed in Annex C of the Stockholm Convention will often have various co-benefits. Conversely, measures to protect human health and the environment from other pollutants will also help to reduce and eliminate chemicals listed in Annex C.
These other pollutants include particulate matter, certain metals (such as mercury), nitrogen oxides (NOx), sulphur dioxide (SO2), and volatile organic compounds. Measures include flue gas cleaning processes, wastewater and solid residue treatment and monitoring and reporting.
Examples of some of these linkages and co-benefits are outlined below, with further details on best available techniques and best environmental practices provided in sections of the document dealing with specific source categories.
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4.5.2 Information, Awareness and Training
Information, awareness and training activities associated with environmental and health concerns and protection may have co-benefits for the reduction of chemicals listed in Annex C and other pollutants.
4.5.3 Flue Gas Cleaning Processes
Various flue gas treatment processes will have co-benefits for chemicals listed in Annex C and other pollutants. Examples include:
Containment, collection and ventilation
These measures will reduce residential and occupational human exposure to total particulate matter, particulate matter less than 10 microns (PM10) and particulate matter less than 2.5 microns (PM2.5). Pollutants associated with particulate matter, such as metals and metal compounds (e.g. lead), and gaseous pollutants such as volatile organic compounds, may also be reduced.
Dust separation processes
Measures such as cyclones, electrostatic precipitators and fabric filters will reduce emissions of particulate matter and pollutants associated with particulate matter to the environment.
Scrubbing processes
These measures will reduce emissions of particulate matter using effective mist eliminators and may reduce gaseous pollutants such as acid gases and mercury. Flue gas desulphurization will reduce emissions of SO2.
Sorption processes
Measures such as activated carbon adsorption will reduce emissions of mercury, volatile organic compounds, sulfur dioxide (SO2), hydrogen chloride (HCl), hydrogen fluoride (HF) and polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/PCDF) as applicable.
Catalytic processes
Measures such as selective catalytic reaction for reduction of NOx may also reduce gas phase emission of chemicals listed in Annex C if catalytic oxidation also occurs in the system. Selective catalytic reaction may also oxidize elemental mercury, which is water soluble and can be removed in flue gas desulphurization systems. Catalytic fabric filters may also reduce volatile organic compounds.
4.6 WASTEWATER TREATMENT PROCESSES
Primary wastewater treatment will remove suspended solids. Tertiary treatment such as activated carbon may remove various organics.
Filter cake from wastewater treatment is regarded as hazardous waste and has to be disposed of in an environmentally sound manner (e.g. specially engineered landfill).
Solid residue treatment processes
Measures such as waste residue solidification and thermal treatment will reduce the total content of pollutants and leaching of various pollutants to the environment.
Monitoring and reporting
Facilities may be required to monitor, measure, estimate and report releases to the environment. These could provide public information on various pollutants and incentives for continual improvements in the environmental performance of the facilities.
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Periodic comprehensive measurement scans of a wide range of pollutants, including PCDD/PCDF, hexachlorobenzene (HCB) and polychlorinated biphenyls (PCB), in addition to routine monitoring of common pollutants, could provide useful information on many potential sources of chemicals listed in Annex C and other pollutants.
4.7 MANAGEMENT OF FLUE GAS AND OTHER RESIDUES
4.7.1 Flue Gas Treatment Techniques (Air Pollution Control Devices)
In principle, reduction of emissions of polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF) can be achieved with the following exhaust gas cleaning processes:
• Afterburners;
• Rapid quench systems;
• Dust separation;
• Scrubbing processes;
• Sorption process;
• Catalytic oxidation.
Air pollution control devices may be wet, dry, or semi-dry, depending on the role of water in the process. Wet and, sometimes, semi-dry air pollution control devices require additional processes to clean any wastewater generated before it leaves the facility.42 Solid waste arising from semi-dry and dry processes (and also from wet processes after wastewater treatment) has to be disposed of in an environmentally sound manner or undergo additional treatment before disposal or potential reuse.
4.7.2 Comparison Of PCDD/PCDF Control Techniques
The techniques that have been found to be most effective at reducing persistent organic pollutants in flue gases are those that utilize adsorbents and particulate control and those that utilize catalysts. Table 1 summarizes the collection efficiencies of selected PCDD/PCDF control techniques.
Costs for PCDD/PCDF control at existing facilities can be reduced by using synergies with existing air pollution control devices:
• Through activated coke injection an existing fabric filter or electrostatic precipitator can be extended to a flow injection reactor to reduce PCDD/PCDF. The additional costs for PCDD/PCDF reduction arise from the storage, transport, injection and disposal of the activated coke, which is used as an additional adsorbent, and safe handling of the carbon and disposal of the residues, which may change in character.
• PCDD/PCDF can be destroyed with an oxidation catalyst. An existing catalyst for the selective removal of nitrogen oxides (NOx) can be used for this purpose. Additional costs arise from enlarging the surface of the catalyst by adding one or two layers of catalyst to achieve PCDD/PCDF concentrations below 0.1 ng I-TEQ/Nm3.43
In addition to the removal or destruction of PCDD/PCDF, other pollutants such as heavy metals, aerosols or other organic pollutants will be reduced.
42 Combustion controls and other factors that affect formation and release of chemicals listed in Annex C of the Stockholm
Convention upstream of the flue gases are described in the sector-specific guidance notes (sections V and VI). 43 1 ng (nanogram) = 1 × 10-12 kilogram (1 × 10-9 gram); Nm3 = normal cubic metre, dry gas volume measured at 0°C and
101.3 kPa. For information on reporting PCDD/PCDF results see section I.C, subsection 3 of the present guidelines.
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Comparison of PCDD/PCDF control systems
Control option PCDD/PCDF removal efficiency
Co-benefits
Cyclone Low efficiency Coarse dust removal
Electrostatic precipitator Low efficiency Designed for dust removal
Bag filter Medium efficiency Designed for dust removal
Wet scrubber Medium efficiency Designed for dust or acid gas removal
Quenching and subsequent high-efficiency wet scrubber
Medium to high efficiency Simultaneous reduction of dust, aerosols, HCl, HF, heavy metals and SO2
Afterburner High efficiency No residues, but quenching of flue gases required
Catalytic oxidation (selective catalytic reaction) High efficiency; destruction of PCDD/PCDF and other organics
No residues, simultaneous reduction of NOx
Catalytic bag filter High efficiency Simultaneous dust removal
Dry absorption in resins (carbon particles dispersed in a polymer matrix)
Depends on the amount of installed material
Selective for PCDD/PCDF; material can be incinerated after use
Entrained flow reactor with added activated carbon or coke/lime or limestone solutions and subsequent fabric filter
Medium to high efficiency Simultaneous reduction of various pollutants such as PCDD/PCDF and mercury; material can be incinerated after usea
Fixed bed or circulating fluidized bed reactor, adsorption with activated carbon or open hearth coke
High efficiency Simultaneous reduction of various pollutants such as PCDD/PCDF and mercury; material can be incinerated after usea
a. As a carbon adsorber will also adsorb mercury, care has to be taken about mercury circulation if the spent carbon is reburnt. Additional mercury removal is therefore needed.
4.7.3 Rapid Quenching Systems
Water quench systems are also used to bring flue gas temperatures down quickly to below the formation threshold for chemicals listed in Annex C of the Stockholm Convention. These systems and associated wastewater treatment systems must be designed to deal with the higher particulate matter loadings that will end up in the scrubber water as a consequence.
4.7.4 Afterburners
Afterburners are either separate from or integrated into the main combustion chamber for destroying unburnt or partially burnt carbon compounds in the exhaust gas. Depending on the actual conditions a catalyst, additional combustion air or a (natural gas-fired) burner may be required. Where appropriate, legislation would indicate minimum temperatures to achieve this destruction for a given process. Measures are required to ensure that the afterburners are actually used as required.
4.7.5 Dust Separation
PCDD/PCDF are released with flue gases via the gas phase as well as particle bound. The fine dust fraction may be enriched in particular due to its high specific surface. Since the separation of the fine dust fraction is not always achieved with electrostatic precipitators, well-designed fabric filters are often more efficient for PCDD/PCDF emission reduction. Addition of sorbents may enhance the removal efficiency (Hübner et al. 2000).
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Cyclones and multicyclones: Cyclones and multicyclones (consisting of several small cyclones) extract particulate matter from the gas stream through the use of centrifugal force. Cyclones are much less effective than devices such as electrostatic precipitators or fabric filters in controlling particulate matter releases and are not used alone in advanced flue gas cleaning applications.
Electrostatic precipitators: Electrostatic precipitators (in Europe these systems are usually referred to as electrostatic filters) are generally used to collect and control particulate matter in combustion gas by introducing a strong electrical field into the flue gas stream. This acts to charge the particles entrained in the combustion gases.
Large collection plates receive an opposite charge to attract and collect the particles. The efficiency of collection is a function of the electrical resistivity of the entrained particles. Electrostatic precipitators efficiently remove most particulate matter, including chemicals listed in Annex C adsorbed to particles.
Formation of chemicals listed in Annex C can occur within the electrostatic precipitator at temperatures in the range of 200 °C to about 450 °C. As temperatures at the inlet to the electrostatic precipitator increase from 200 °C to 300 °C, PCDD/PCDF concentrations have been observed to increase with increase in temperature. As the temperature increases beyond 300 °C, formation rates decline.
Typical operational temperatures for electrostatic precipitators are 160 °C – 260 °C. Operation at higher temperatures (e.g. above 250 °C) is generally avoided as this may increase the risk of PCDD/PCDF formation.
Wet electrostatic precipitators use liquids, usually water, to wash pollutants off the collection plates. These systems operate best when the incoming gases are cooler or moist.
Condensation electrostatic precipitators use externally water-cooled bundles of plastic tubes that collect fine liquids or solids by facilitating condensation with a water quench.
Fabric filters: Fabric filters are also referred to as baghouses or bag or sleeve filters. These particulate matter control devices are highly effective in removing chemicals listed in Annex C that may be associated with particles and any vapors that adsorb to the particles in the exhaust gas stream.
Filters are usually bags of 16 to 20 cm diameter, 10 m long, made from woven fibreglass material or polytetrafluoroethylene (PTFE), and arranged in series (see Table 2). An induction fan forces the combustion gases through the tightly woven fabric, which provides a bed for filter cake formation. The porosity of the fabric and the resulting filter cake allows the bags to act as filter media and retain a broad range of particle sizes down to less than 1 µm in diameter (although at 1 µm capture efficiency begins to decrease).44Fabric filters are subject to water damage and corrosion and gas streams must be maintained above the dew point (130-140 °C) to prevent these effects. Some filter materials are more resistant to damage. Fabric filters are sensitive to acids; therefore, they are commonly operated in combination with spray dryer adsorption systems for upstream removal of acid gases. Spray drying also serves to cool the inlet gases. Without such cooling, chemicals listed in Annex C may be formed in the fabric filters, similar to the situation with electrostatic precipitators. Dust removal systems are compared in Table 3.
Table 2: Characteristics of fabric filter materials
Fabric Maximum temperature
(°C)
Resistance
Acid Alkali Physical flexibility
Cotton 80 Poor Good Very good
Polypropylene 95 Excellent Excellent Very good
Wool 100 Fair Poor Very good
Polyester 135 Good Good Very good
Nylon 205 Poor to fair Excellent Excellent
PTFE 235 Excellent Excellent Fair
Polyamide 260 Good Good Very good
Fibreglass 260 Fair to good Fair to good Fair
44 1 µm (micrometre) = 1×10−6 metre.
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Source: European Commission 2005.
Table 3: Comparison of dust removal systems
Dust removal system
Typical dust emission
concentrations
Advantages Disadvantages
Cyclone and multicyclone
Cyclones:
200–300 mg/m³
Multicyclones:
100–150 mg/m³
Robust, relatively simple and reliable
Applied in waste incineration
Only for pre-dedusting
Relatively high energy consumption (compared to electrostatic precipitator)
Electrostatic precipitator, dry
< 5–25 mg/m³
Relatively low power requirements
Can use gas temperatures in the range 150 °C – 350 °C but effectively limited to 200 °C by PCDD/PCDF issue (see right)
Formation of PCDD/PCDF if used in range 200 °C – 450 °C
Electrostatic precipitator, wet
< 5–20 mg/m³
Able to reach low pollutant concentrations
Mainly applied for post-dedusting
Generation of process wastewater
Increase of plume visibility
Bag filter
< 5 mg/m³ Layer of residue acts as an additional filter and as an adsorption reactor
Relatively high energy consumption (compared to electrostatic precipitator)
Sensitive to condensation of water and to corrosion
Source: European Commission 2005.
4.7.6 Scrubbing Processes
Spray dry scrubbing: Spray dry scrubbing, also called spray dryer adsorption or semi-wet scrubbing, removes both acid gas and particulate matter from the post-combustion gases. In a typical spray dryer, hot combustion gases enter a scrubber reactor vessel.
An atomized hydrated lime slurry (water plus lime) is injected into the reactor at a controlled velocity. The slurry rapidly mixes with the combustion gases within the reactor. The water in the slurry quickly evaporates, and the heat of evaporation causes the combustion gas temperature to rapidly decrease. The neutralizing capacity of hydrated lime can reduce the acid gas constituents of the combustion gas (e.g. HCl and SO2) by as much as 90%. However at waste incinerator plants spray dry scrubbing systems also typically achieve 93% SO2 and 98% HCl control. A dry product consisting of particulate matter and hydrated lime either settles to the bottom of the reactor vessel or is captured by the downstream particulate capture device (electrostatic precipitator or fabric filter).
Spray drying technology is used in combination with fabric filters or electrostatic precipitators. In addition to reducing acid gas and particulate matter and control of volatile metals, spray drying reduces inlet temperatures to help reduce formation of chemicals listed in Annex C. PCDD/PCDF formation and release is substantially prevented by quenching combustion gases quickly to a temperature range that is unfavorable to their formation, and by the higher collection efficiency of the resulting particulate matter.
Solid residue from spray dry usually contains a mixture of sulphates, sulphites, fly ash, pollutants and unreacted adsorbents and has to be landfilled.
Wet scrubbers: Wet scrubbers encompass a number of processes designed for acid gas and dust removal. Alternative technologies include jet, rotation, venturi, spray, dry tower and packed tower scrubbers (European Commission 2005). Wet scrubbers help reduce formation and release of chemicals listed in Annex C in both vapour and particle forms. In a two-stage scrubber, the first stage removes hydrogen chloride (HCl) through the introduction of water, and the second stage removes sulphur dioxide (SO2) by addition of caustic or hydrated lime. In the wet scrubbing process gypsum can be produced, which reduces the amount of waste going to landfills.
In the case of packed tower scrubbers, packing that contains polypropylene embedded with carbon can be used for specific removal of PCDD/PCDF.
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Wet scrubbers have the highest removal efficiencies for soluble acid gases among the demonstrated techniques where removal efficiency is a function of pH of scrubber water. Solid particles in scrubber water may also cause interaction with PCDD/PCDF in the mobile gas stream, thus influencing the reliability of the relationship between results obtained from periodic stack gas monitoring and the destruction efficiency of the plant.
Memory effects are mainly due to the accumulation of various PCDD/PCDF congeners in plastic materials used in wet scrubbers. The effect may last several hours or may be long-term. As such, there is a preference for the removal of PCDD/PCDFF before wet scrubbing to reduce memory effects. An assessment should be carried out regarding PCDD/PCDF build-up in the scrubber and suitable measures adopted to deal with this build-up and prevent scrubber breakthrough releases. Particular consideration should be given to the possibility of memory effects during shut-down and start-up periods.
Fine dust absorber: Fine dust absorbers are equipped with a large number of pneumatic two-component jets (water and compressed air). Such high-efficiency absorbers can separate the PCDD/PCDF-covered fine dust through the very fine spray-like dispersal of the absorption solution and the high speed of the water droplets. In addition, the cooling of the exhaust gases and the undercooling in the dust absorber initiate condensation and improve the adsorption of volatile compounds on the dust particles. The absorption solution is treated by wastewater processing. The addition of adsorbents may further improve PCDD/PCDF reduction. With simple scrubbers for the separation of acid exhaust gases appreciable PCDD/PCDF removal is not possible. The achievable emission values of high-efficiency absorbers are in a range of 0.2–0.4 ng I-TEQ/Nm3. This is equal to a separation efficiency of approximately 95% (Hübner et al. 2000). Waste arising from this process is normally disposed in a specially engineered landfill.
4.7.7 Sorption Processes
Fixed bed filters: In the fixed bed process, precleaned exhaust gases are conducted at temperatures of 110 – 150 °C through an activated carbon based adsorbent material. Necessary devices include fresh adsorbent supply, fixed bed reactor and spent adsorbent system. The activated coke bed separates residual dust, aerosols and gaseous pollutants. It is moved cross-current and countercurrent in order to prevent blockage of the bed through, for example, residual dust.
Usually, the PCDD/PCDF-covered coke is disposed off through (internal) combustion, by which organic pollutants are to a large extent destroyed. Inorganic pollutants are released via slugs or separated in the exhaust gas fine cleaning again. The fixed bed process achieves PCDD/PCDF reductions of 99.9%. Compliance with a performance standard of 0.1 ng I-TEQ/Nm3 is state-of-the-art (Hübner et al. 2000; Hartenstein 2003).
Flow injection process: In order to enhance the separation efficiency of fabric filters, adsorbents with high PCDD/PCDF take-up capacities are injected into the exhaust gas stream. In general, activated coal or hearth-type coke are used as adsorbents together with lime hydrate. The separation is carried out in a fabric filter located at the end of the process, where adsorbents and dust are separated and a filter layer is formed. The appropriate disposal of the PCDD/PCDF-containing filter dust has to be assured. Conventional operation temperatures range from 135 °C to 200 °C.
Usually, the PCDD/PCDF-covered coke is disposed off through (internal) combustion. By (internal) combustion organic pollutants are destroyed to a large extent. Inorganic pollutants are released via slugs or separated in the exhaust gas fine cleaning again.
With the flow injection process, filtration efficiencies of 99% are achieved. The PCDD/PCDF removal efficiency depends on the quality of the adsorbent injection, the effectiveness of the adsorbent-flue gas mixing system, the type of particulate filter and the operation of the system. Another critical parameter is the mass flow rate of the injected adsorbent. For applying this technology most effectively a baghouse should be used. Compliance with a performance standard of 0.1 ng I-TEQ/Nm3 is state-of-the-art (Hübner et al. 2000; Hartenstein 2003).
Entrained flow reactor: For this technology the same adsorbents are applied as used for the adsorbent injection process. However, the adsorbent is usually applied in a mixture with hydrated lime or other inert materials such as limestone, quicklime or sodium bicarbonate. Upstream of the entrained flow reactor for flue gas polishing, a conventional flue gas cleaning system is required for removing the bulk of the fly ash and the acid gases. Necessary devices include fresh adsorbent supply, fabric filter, recirculation system and spent adsorbent system. Conventional operation temperatures range from 110 °C to 150 °C. Compliance with a performance standard of 0.1 ng I-TEQ/Nm3 is state-of-the-art (Hartenstein 2003).
Dry absorption (in resins): A new flue gas cleaning technology has been developed that combines adsorption and absorption of PCDD/PCDF into plastic structures containing dispersed carbon particles. In this new material, the PCDD/PCDF are first adsorbed in the polymer matrix and then diffuse to the surface of the carbon particles where they are irreversibly absorbed. The most common application of AdioxTM is tower packings employed in gas cleaning systems. Until now, more than 30 full-scale incineration lines with flow gases ranging from 5,000 to 100,000 Nm3/h are installed in wet flue
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gas cleaning systems. The removal efficiency depends on the amount of installed material. The technology can be applied as the main PCDD/PCDF cleaning system or to increase the safety margins or to reduce the memory effect in wet scrubbers. If Adiox is employed in dry adsorbers, the removal efficiency per installed amount is higher (Andersson 2005).
4.7.8 Catalytic Oxidation of PCDD/PCDF
Selective catalytic reactions: Catalytic oxidation processes, which are normally used for reducing nitrogen oxide emissions, are applied for PCDD/PCDF destruction as well. Therefore, effective dedusting (e.g. emission values of particulate matter of below 5 mg/m3) is a requirement for achieving low overall emissions of chemicals listed in Annex C. For the removal of PCDD/PCDF only (e.g. with the DeDiox process), ammonia injection is not necessary. In this case, operation temperatures range from 130 °C to 350 °C.
The main advantages of this process are an easy operation and no residues apart from very little spent catalyst. Therefore, catalytic oxidation does not cause disposal problems.
Decomposition reaction for Cl4DD: C12 H4 Cl4 O2 + 11 O2 → 12 CO2 + 4 HCl
In general, the installations are operated in clean gas circuits, i.e., dust and heavy metals are separated before the catalyst in order to prevent rapid wear and deactivation of the catalysts through catalyst poisons.
With catalytic oxidation, only the PCDD/PCDF fraction in the gas phase can be captured. Nevertheless, emission reductions of 95 to 99% can be achieved. PCDD/PCDF reduction rate depends on the installed catalyst volume, the reaction temperature and the space velocity of the flue gas through the catalyst. PCDD/PCDF testing showed emission values lower than 0.01 ng I-TEQ/Nm3 (dry basis, 11% O2).
In the selective catalytic reaction process for combined removal of PCDD/PCDF and NOx an air-ammonia mix is injected into the flue gas stream and passed over a mesh catalyst (Figure 6). The ammonia and NOx react to form water and N2 (European Commission 2005; Hübner et al. 2000; Hartenstein 2003).
Catalytic bag filters: Catalytic bag filters with PTFE membrane enable dust concentrations in cleaned flue gases of about 1–2 mg/Nm3. Currently applications are known in waste incineration, crematoria, metal industries and cement plants. Filter bags that are impregnated with a catalyst, or contain a powdered catalyst directly mixed in fibre production, have been used to reduce PCDD/PCDF emissions. This type of filter bag is generally used without the addition of activated carbon so that the PCDD/PCDF can be destroyed on the catalyst rather than absorbed in the carbon and discharged as solid residues. They operate at temperatures between 180 °C and 250 °C.
A catalytic filter system incorporates microporous PTFE fibre with the catalyst particles built into the fibre structure. In this process, PTFE particles are mixed with the catalyst and processed to produce fibres. A microporous ePTFE membrane is laminated to the ePTFE/catalyst microporous fibres to produce the filtration medium. This material is then sewn into filter bags, which can be installed in a baghouse. Applications at German and Japanese crematoria gave emissions below 0.1 ng I-TEQ/Nm3 (Xu et al. 2003).
4.7.9 Treatment of Flue Gas Treatment Residues
The treatment of flue gases to remove contaminants (as described above) will generate a number of residues, which must either be disposed of or undergo additional treatment before disposal and potential reuse. Appropriate options for disposal or reuse of these residues will depend on the type and degree of contamination, as well as the waste matrix (inert fraction). Flue gas treatment residues may be solids (e.g. baghouse or electrostatic precipitator dust), wastewaters or slurries containing varying amounts of dissolved and suspended solids (e.g. from wet electrostatic precipitators and other wet scrubbers) or spent adsorbent materials (e.g. saturated resins). These residues may contain, in addition to the inert materials, toxic metals, such as arsenic, lead, cadmium, mercury or others, as well as PCDD/PCDF.45 These residues could be handled in one of several different ways, as discussed below. Current practices for the treatment and disposal of flue gas treatment residues include reuse in the process from which they were derived, disposal to landfill, stabilization and subsequent disposal, vitrification, incorporation into road-making materials, disposal or valorization in salt or coal mines, and catalytic or thermal treatment.
According to the Basel Convention on the Control of Transboundary Movements of Hazardous Wastes and Their Disposal, Annex I wastes, including fly ashes, containing PCDD or PCDF are classified as hazardous waste.
45 For additional guidance on management of residues based on their concentration of persistent organic
pollutants (including when the persistent organic pollutant content is low, as per Stockholm Convention Article
6.1 (d) (ii)), see Basel Convention Secretariat 2005.
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Management of solid flue gas treatment residues46
One major flue gas treatment residue (or air pollution control residue) is fly ash. Fly ash removal from flue gas by use of dry scrubbers, cyclones or fabric filters will result in dry fine solid particulate material having a range of properties and contaminants depending on the combustion source that produced it. Air pollution control of many types of combustion sources, including municipal and hazardous waste incinerators, steel-making electric arc furnaces and cement kilns, can generate such a fine dry particulate material when dry controls are used. These dry particulate residues will contain different levels of metals (depending on feedstocks) and may also have some PCDD/PCDF and other polycyclic aromatic hydrocarbons adsorbed onto them, depending on the combustion conditions.
Contaminant releases to the environment from these dry materials may be by a number of routes, including leaching to groundwater, wind-blown dust, crop plant uptake or direct ingestion by humans or wildlife (potentially including farm animals). All management of these materials must be done with consideration of these potential releases, as required by the particular residue. A number of management options, including both beneficial reuse and treatment or disposal, are available for these dry residues, depending on the properties of the inert fraction and the type and level of contamination with metals and organics.
Residue reuse
Limited reuse is appropriate for dry, solid residues.
A major reuse of coal fly ash is in the construction of roads or buildings because of its pozzolanic properties. It can be used in cement and concrete production.
Fly ashes should never be used as soil amendment in agricultural or similar applications. Addition to soil may result in subsequent dispersion of the ash and any contaminants. In agricultural uses plants may take up contaminants, resulting in exposure to human or animals that consume the plants. Pecking or grazing animals may directly ingest contaminants, with subsequent exposure to humans when they consume the animals or animal products (e.g. milk and eggs).
Stabilization and solidification
Treatment and disposal options for solid residues from flue gas control systems include solidification or stabilization with Portland cement (or other pozzolanic materials), alone or with additives or a number of thermally based treatments, followed by appropriate disposal (based on anticipated releases from the treated residuals). Some residues with low levels of contamination may require no treatment before disposal in a landfill, based on an assessment of their contaminant release potential.
The main purpose of solidification is to produce a material with physical and mechanical properties that promote a reduction in contaminant release from the residue matrix. An addition of cement, for example, generally decreases hydraulic conductivity and porosity of the residue, while increasing durability, strength and volume.
Solidification methods commonly make use of several, mostly inorganic, binder reagents: cement, lime and other pozzolanic materials such as coal fly ash, blast furnace bottom ash or cement kiln dust, although some organic binders such as bitumen/asphalt or paraffin and polyethylene can also be used. Combinations of binders and various types of proprietary or non-proprietary additives are used as well. By far the most prevalent solidification technique is cement stabilization.
The main concept of chemical stabilization is to bind the heavy metals in more insoluble forms than those in which they occur in the original untreated residues. These stabilization methods make use of both the precipitation of metals in new minerals and the binding of metals to minerals by sorption. This process includes the solubilization of the heavy metals in the residues and a subsequent precipitation in, or sorption to, new minerals.
Several of the stabilization methods incorporate an initial washing step whereby a major part of soluble salts and to some extent metals are extracted before chemical binding of the remaining metals. These methods are completed by dewatering the stabilized product.
Treatment options using extraction and separation processes can, in principle, cover all types of processes for extracting specific components from the residues. However, most emphasis has been put on processes involving the extraction of heavy metals and salts with acid.
While stabilization and solidification approaches to waste treatment are typically directed at controlling the release of contaminant metals, PCDD/PCDF and other polycyclic aromatic hydrocarbons may be only partially controlled by these treatments (although these compounds are very hydrophobic and so generally do not leach very fast or at very high concentrations). Addition of adsorbents (such as clays or activated carbon), which are then incorporated into the treated
46 The subparagraphs in paragraph 2 are cited from European Commission 2005, chapter 2.7.3.
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waste matrix, can improve control of these organics. Laboratory leaching tests or other evaluations should be applied for assessing the effectiveness of any of these treatment approaches.
4.7.10 Thermal Treatment of Flue Gas Treatment Residues
Thermal treatment can be grouped into three categories: vitrification, melting and sintering. The differences between these processes are chiefly related to the characteristics and properties of the final product.
• Vitrification is a process whereby residues are treated at high temperature (currently 1,300 °C to 1,500 °C) and then quickly quenched (with air or water) to obtain an amorphous glassy matrix. After cooling down, the melt forms a single-phase product called a vitrificate. The vitrificate can be a glass-like or stone-like product, depending on the melt composition. Additives are sometimes (but not usually) added to the residues to favour the formation of the glassy matrix.
• Melting is similar to vitrifying, but the quenching step is controlled to allow crystallization of the melt as much as possible. It results in a multiphase product. Temperatures and the possible separations of specific metal phases are similar to those used in vitrifying. It is also possible to add specific additives to favour the crystallization of the matrix.
• Sintering involves the heating of residues to a level where bonding of particles occurs and the chemical phases in the residues reconfigure. This leads to a denser product with less porosity and a higher strength than the original product. Typical temperatures are around 900 °C. When municipal solid waste is incinerated some level of sintering will typically take place in the incineration furnace. This is especially the case if a rotary kiln is used as part of the incineration process.
Regardless of the actual process, the thermal treatment of residues in most cases results in a more homogeneous, denser product with improved leaching properties. The energy requirements of stand-alone treatments of this type are generally very high.
These processes are generally employed to immobilize metals or radiological contaminants, and will significantly reduce the potential for leaching of many contaminants likely to be found in flue gas treatment solid residues. Again, leaching tests may be useful in evaluating the effectiveness of these treatments. Because these are high-temperature processes, any PCDD/PCDF or other polycyclic aromatic hydrocarbons adsorbed onto the original dry solids may well be destroyed as part of the treatment process. However, as high-temperature processes, air emissions must be monitored from the treatment itself, as it may result in air pollution control residues of its own, which will then need to be managed in an environmentally sound manner.
4.7.11 Treatment of Spent Dry Adsorption Resins
Use of specialized dry resins to remove flue gas contaminants such as PCDD/PCDF before release to the air will also generate a treatment residue in the form of the spent resin cartridge or bulk resin material. If such resins are designed to be regenerated, either through thermal desorption or by other means, then the regeneration process will itself generate residues or releases to the air that must be controlled and managed. If spent resins are to be disposed of after a single use (or for regenerated resins that are no longer useful), evaluation of the level and type of contaminants on the resin will help determine whether it can be landfilled without treatment, or requires some treatment before disposal. For some resins, incineration or some other treatment that destroys both the resin and adsorbed contaminants may also be a possibility.
4.7.12 Treatment of Wastewaters
Many processes have wastewater streams that cannot reasonably be released to the open environment without treatment. Flue gas treatment systems are similar to chemical processes in that they each may have wastewater treatment needs.
Various wet processes may also be used to remove pollutants from flue gas streams and so prevent their release to the air. Resultant wastewaters will contain some amount of dissolved as well as suspended materials.
As with many chemical processes, the first step in handling these flue gas treatment residues, particularly where metals are the main concern, is often separation of the liquid and solid portions. This can often be accomplished using settling ponds or tanks, although land-based ponds may require liner systems to prevent leaching of contaminants into groundwater. The solid fraction may be further dewatered and dried and then handled as a solid material as discussed above. The water portion may require further removal of contaminants before meeting requirements for discharge to surface water or
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groundwater recharge areas. Treatments could include addition of chemicals to precipitate out metal salts, or use of adsorbent materials to remove organics. These wastewater treatment residuals would then also require appropriate treatment and disposal.
Flue gas treatment residues from wet processes may also contain organic constituents, including PCDD/PCDF or other polycyclic aromatic hydrocarbons. Biological treatment in ponds or impoundments can usually reduce the concentration of these and other organic constituents that may occur in flue gas treatment residues.
Most wastewaters do not present opportunities for reuse. However, treatment of flue gas to remove sulphur, using ground and slaked lime, presents one such opportunity. In the fully oxidized form of this treatment, the solid residue in the wastewater is a high-quality calcium sulphate, or gypsum. This gypsum can be dewatered and used to manufacture wallboard for residential or other buildings, sometimes at costs that are much lower than those for wallboard from mined gypsum.
4.8 TRAINING OF DECISION MAKERS AND TECHNICAL PERSONNEL
The importance of technical assistance, in particular training, as a need to strengthen the national capabilities of developing countries (in particular the least developed) and countries with economies in transition, is recognized in the preambular paragraphs of the Stockholm Convention, and Article 12 states: “Parties recognize that rendering of timely and appropriate technical assistance in response to requests from developing country Parties and Parties with economies in transition is essential to the successful implementation of this Convention.”
In this regard capacity-building technical assistance, in particular training in available environmental methodologies, practices and tools, with specific reference to the particular needs of a Party, may give a better understanding of procedures for conducting, on a sustained basis, daily operational practices and preventive maintenance of the best available techniques and best environmental practices being introduced as components of the Party’s national implementation plan. It is of utmost importance that capacity-building technical assistance, in particular training, should be provided at both managerial and technical or operating levels in public and private sector organizations involved in the implementation of the guidelines for best available techniques and best environmental practices. Taking into consideration the complexity of many best available techniques and the required holistic and preventive approach for introducing best environmental practices, life cycle management, in addition to relevant health and safety issues, should be given priority consideration in capacity-building, with a risk prevention and reduction approach.
4.9 TESTING, MONITORING AND REPORTING
4.9.1 Testing and Monitoring
Monitoring of releases of chemicals listed in Annex C of the Stockholm Convention is critical to achieving the goals of the Convention. However, many developing countries and countries with economies in transition do not have the necessary capacity in terms of costs, technical expertise and laboratories and, in some cases, the economic returns for facilities may not be sufficient to cover all costs associated with monitoring. Consequently, it is necessary to establish and strengthen regional, subregional and national technical capacity and expertise, including laboratories. This enhanced capacity may also promote monitoring at specified intervals for existing sources.
Proposals for new facilities or proposals to significantly modify existing facilities should, as part of best available techniques and best environmental practices, include plans for the evaluation of compliance with the target values for releases of chemicals listed in Annex C in stack gases and other outputs that are given in this guidance document. Accordingly, as part of ongoing operation, these facilities should demonstrate, through monitoring at specified intervals, as appropriate, that the performance levels continue to be achieved.47, 48
4.9.2 Sampling and Analysis of PCDD/PCDF and Dioxin-like PCB
Validated, standardized methods of sampling and analysis are available for polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF) but not yet for all chemicals listed in Annex C (Table 4). The methods for sampling
47 Determination of the mass concentration of chemicals listed in Annex C in releases from a given source should follow
nationally or internationally recognized standard methods of sampling, analysis and evaluation of compliance. 48 In most cases, target values currently exist only for PCDD/PCDF.
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and monitoring for polychlorinated biphenyls (PCB) and hexachlorobenzene (HCB) must be developed and validated. Methods for sampling stack gases include those with sampling periods of 4 to 8 hours as well as those that are quasi-continuous. Most if not all regulatory regimes for PCDD/PCDF are currently based on toxic equivalents (TEQ).49
Sampling of PCDD/PCDF emissions to date is mainly undertaken by using one of the methods listed in Table 4.
Table 4: Methods for stack sampling and analysis of PCDD/PCDF and PCB
Method Substances analyzed Analytical principle Reference
EN 1948 PCDD/PCDF HRGC/HRMS European Committee for Standardization
US EPA Method 23 PCDD/PCDF HRGC/HRMS U.S. Environmental Protection Agency
VDI Method 3499 PCDD/PCDF HRGC/HRMS Association of German Engineers (VDI)
Canada Methods EPS 1/RM/2 and EPS 1/RM/3
PCDD/PCDF, PCB HRGC/HRMS Environment Canada
Japanese Industrial Standard K 0311
PCDD/PCDF, dioxin-like PCB HRGC/HRMS Japanese Industrial Standards Committee
PCDD/PCDF analysis is carried out using high-resolution mass spectrometry. Quality control procedures are required at each stage of the analysis and recovery spike concentrations associated with both sampling and extraction. United States EPA Method 23 specifies that all recoveries should be between 70% and 130%. Canada provides detailed quality assurance guidance on the analysis of samples containing dioxins and furans in a range of matrices in its Reference Method EPS 1/RM/2.
The European Standard EN 1948 has been developed for separation detection, and quantification of PCDD/PCDF and dioxin-like PCB in emission samples from stationary sources at concentrations at about 0.1 ng TEQ/Nm³. Parts 1-3 detail sampling; extraction and clean-up; and identification and quantification of PCDD/PCDF (adopted in 1996, revision adopted in 2006). Part 4 details the standard for dioxin-like PCB (adopted in 2007).
The lower detection limits measured during the validation test of EN 1948 at a municipal solid waste incinerator varied between 0.0001 and 0.0088 ng/Nm3 for the 17 individual PCDD/PCDF toxic congeners (CEN 1996c; see also CEN 1996a, 1996b)
In the new draft of EN 1948-3 of February 2004 (updating CEN 1996c), Annex B, the uncertainty for the complete procedure is given to be 30–35% and the external variability is estimated to be ± 0.05 ng I-TEQ/m3 at a mean concentration 0.035 ng I-TEQ/Nm3.
Taking into account the toxic equivalence factors for the individual congeners the resulting overall detection limits vary between 0.001 and 0.004 ng I-TEQ/Nm3. It is reasonable to assume that concentrations lower than 0.001 ng I-TEQ/m3 should be considered as being below the detection limit.
A study performed by Environment Canada assessed the variability of sampling and analysis of 53 sets of PCDD/PCDF emission data from 36 combustion facilities. The limit of quantification for PCDD/PCDF emissions was estimated to be 0.032 ng I-TEQ/m3, although this limit may vary depending on sampling volume, interfering substances and other factors.
Interferences should be expected to occur from compounds that have similar chemical and physical properties to PCDD/PCDF (CEN 1996c).
4.9.3 Limit of Detection and Limit of Quantification
The “limit of detection” (LOD) is the smallest amount or concentration of analyte in the test sample that can be reliably distinguished, with stated significance, from the background or blank level.
49 To determine TEQ concentrations, each of the 17 PCDD/PCDF congeners that are of greatest toxicological concern are
quantified using capillary gas chromatograph high-resolution/mass spectrometer.
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The “limit of quantification” (LOQ) of an analytical procedure is the lowest amount or concentration of analyte in a sample which can be quantitatively determined with an acceptable level of precision and accuracy. The limit of quantification should be stated if it is necessary to specify a lower limit of measurement below which acceptable accuracy and precision is not attained. Using the method, carry out a number of independent determinations, preferably >20, using a sample which is known to contain the analyte at between 2 and 5 times the estimated detection limit. The limit of quantification is the concentration at which an acceptable degree of performance, in terms of RSD% (relative standard deviation), is obtained. It is usually the case that the limit of quantification corresponds to the lowest standard concentration level in the calibration range.
In the context of regulatory limit values, or for reporting measured concentrations, there is no general rule how to treat results below LOQ. Very often, the regulations or laws define the way of reporting results. For reporting, the following definitions should be taken into account:
− Lower-bound: Non-quantifiable peaks are set to zero − Upper-bound: Full LOQ included in presentation of result
Criteria should be set to define lower-bound and upper-bound concentrations and the reporting value and therefore the LOQ should be at least 1/5 of the regulatory limit or level of interest or baseline concentration.
4.9.4 Gas Reference Conditions
Table 5 presents reference condition conversions used in Canada, the European Union and the United States of America.
Table 5: Reference Condition Conversions
Unit Country/Region Temperature
(°C) Pressure
(atm) Gas conditions
Nm3 (Normal cubic
meter)
European Union (EU) 0 1 Dry; 11% oxygen for municipal waste incinerators and co-combustion of waste; 10% oxygen for cement plants; no oxygen level requirements for all other plants (i.e., concentrations are reported at the actual oxygen content and are not normalized to any fixed O2 content)
Rm3 (Reference cubic
meter)
Canada 25 1 Dry; 11% oxygen for incinerators and coastal pulp and paper mill boilers, operating oxygen levels for sinter plants and steel manufacturing electric arc furnaces
Sm3 (or dscm) (Dry standard cubic meter)
United States (U.S.) 20 1 Dry; 7% oxygen or 12% carbon dioxide for incinerators and most combustion sources.
0.1 ng TEQ/Nm3 (EU) = 0.131 ng TEQ/Sm3 (U.S.) = 0.092 ng TEQ/Rm3 (Canada)
4.9.5 Bioassay Methods
Four bioassay methods, three reporter gene bioassay methods and one enzyme imunoassay method, have been approved in Japan for measuring dioxins in emission gas, dust and cinders from waste incinerators. The methods provide a less costly alternative to high-resolution gas chromatography/mass spectrometry and are approved for measuring emissions from incinerators with a capacity less than 2 tons/hour (emission standards for new facilities: 5 ng WHO-TEQ/Nm3) and dust and cinders from all waste incinerators (treatment standard 3 ng WHO-TEQ/g).
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Table 6: Bioassay methods for stack and residue measurements at small waste incinerators
Method Analytical Principle Reference
CALUX Assay Reporter gene assay Xenobiotic Detection Systems International
P450 Human Reporter Gene System
Reporter gene assay Columbia Analytical Services
AhR Luciferase Assay Reporter gene assay Sumitomo Chemical Co., Ltd
Guidelines for appropriate monitoring programmes are also necessary. In that regard, the United Nations Environment Programme (UNEP, 2004) has developed guidance for prioritizing measurements and minimizing the number of measurements for impact assessment. The European Commission has prepared a reference document on the general principles of monitoring; and some companies and industry associations have agreed monitoring requirements. Model legislation and regulations will also facilitate the establishment and implementation of programmes to monitor releases of chemicals listed in Annex C, including such approaches as bioassay monitoring.