3.1 safety

Chemical Engineering Design

CHAPTER 3CHAPTER 3PROCESS DESIGN AND SAFETYPROCESS DESIGN AND SAFETY

3.1 Safety

3.2 Case study on process design and safety

3.3 Chemistry and separations

3.4 Unit ratio material balance

3.5 Detailed flow sheet


Course OutcomeCourse Outcome

Ability to explain and identify process design and safety.

Chemical Engineering Design© 2012 G.P. Towler / UOP. For educational use in conjunction with Towler & Sinnott Chemical Engineering Design only. Do not copy

3.1 SAFETY3.1 SAFETY


SafetySafety

The safe design and operation of The safe design and operation of facilities is of paramount facilities is of paramount

importance to every company that importance to every company that is involved in the manufacture of is involved in the manufacture of

fuels, chemicals and fuels, chemicals and pharmaceuticalspharmaceuticals

© 2012 G.P. Towler / UOP. For educational use in conjunction with Towler & Sinnott Chemical Engineering Design only. Do not copy


Safety & EnvironmentSafety & Environment

Processes must meet acceptable safety and environmental Processes must meet acceptable safety and environmental performance standards because:performance standards because:

• It is required by lawIt is required by law

• The costs (human, social, economic) of non-compliance The costs (human, social, economic) of non-compliance can be catastrophiccan be catastrophic

• Lax attitudes are reflected in insurance premiums, stock Lax attitudes are reflected in insurance premiums, stock pricesprices

• Moral and ethical obligationsMoral and ethical obligations



Major Chemical Plant Safety LegislationMajor Chemical Plant Safety Legislation

• The Occupational Safety and Health Act (OSHA);The Occupational Safety and Health Act (OSHA); 29 U.S.C. 29 U.S.C. 651 et seq. (1970) 651 et seq. (1970) – Employers must provide a place of employment free from recognized Employers must provide a place of employment free from recognized

hazards to safety and health, such as exposure to toxic chemicals, hazards to safety and health, such as exposure to toxic chemicals, excessive noise levels, mechanical dangers, heat or cold stress, or excessive noise levels, mechanical dangers, heat or cold stress, or unsanitary conditions.unsanitary conditions.

• The Emergency Planning & Community Right-To-Know Act The Emergency Planning & Community Right-To-Know Act (EPCRA);(EPCRA); 42 U.S.C. 11011 et seq. (1986) 42 U.S.C. 11011 et seq. (1986) – To help local communities protect public health, safety, and the environment To help local communities protect public health, safety, and the environment

from chemical hazards. from chemical hazards.

• The Toxic Substances Control Act (TSCA);The Toxic Substances Control Act (TSCA); 15 U.S.C. s/s 2601 15 U.S.C. s/s 2601 et seq. (1976) et seq. (1976) – Allows EPA to track industrial chemicals and ban their manufacture or importAllows EPA to track industrial chemicals and ban their manufacture or import



Chemical Plant HazardsChemical Plant Hazards• To design a safe process or product we need to To design a safe process or product we need to

understand and mitigate the associated hazardsunderstand and mitigate the associated hazards

• Materials hazardsMaterials hazards– ToxicityToxicity– FlammabilityFlammability– Incompatibility (corrosivity and reactivity)Incompatibility (corrosivity and reactivity)

• Process hazardsProcess hazards– OverpressureOverpressure– Explosions Explosions – Loss of containmentLoss of containment– NoiseNoise



Materials HazardsMaterials Hazards



Materials Hazards: ToxicityMaterials Hazards: Toxicity• Almost every chemical is toxic if you get enough of itAlmost every chemical is toxic if you get enough of it

• Chemical plants tend to have large enough amounts to cause Chemical plants tend to have large enough amounts to cause serious concern for workers and local residentsserious concern for workers and local residents

• Process design needs to considerProcess design needs to consider– Elimination or substitution of the most hazardous compoundsElimination or substitution of the most hazardous compounds

– Prevention of releasesPrevention of releases

– ContainmentContainment

– Disposal (via effective collection or vent systems)Disposal (via effective collection or vent systems)

– VentilationVentilation

– Emergency proceduresEmergency procedures



Toxicity DefinitionsToxicity Definitions• Acute Effects Acute Effects

• Symptoms develop rapidly (e.g. burns to skin after direct contact)Symptoms develop rapidly (e.g. burns to skin after direct contact)• Normally the result of short-term exposuresNormally the result of short-term exposures

• Chronic EffectsChronic Effects• Symptoms develop over a long period of time (e.g. cancer)Symptoms develop over a long period of time (e.g. cancer)• Often but not always the result of long-term exposure Often but not always the result of long-term exposure • Chronic conditions usually persist or recur frequentlyChronic conditions usually persist or recur frequently

• LDLD5050

• Lethal dose at which 50% of test animals are killedLethal dose at which 50% of test animals are killed• Usually expressed in mg/kg body massUsually expressed in mg/kg body mass• Indicates acute effects onlyIndicates acute effects only

• Threshold Limit Value (TLV) or Permissible Exposure Limit (PEL)Threshold Limit Value (TLV) or Permissible Exposure Limit (PEL)• Concentration that it is believed the average worker can safely be exposed to for Concentration that it is believed the average worker can safely be exposed to for

40 hr work week40 hr work week• Recommended PEL values are published by OSHA Recommended PEL values are published by OSHA

http://www.osha.gov/SLTC/healthguidelines/• Recommended TLV values are provided by the American Conference of Recommended TLV values are provided by the American Conference of

Government Industrial Hygienists Government Industrial Hygienists http://www.acgih.org/home.htm© 2012 G.P. Towler / UOP. For educational use in conjunction with Towler & Sinnott Chemical Engineering Design only. Do not copy


Toxicity DataToxicity Data

Compound PEL (ppm) LD50 (mg/kg)

Carbon monoxide 50 1807Carbon disulfide 20 3188Chlorine 1 239Chlorine dioxide 0.1 292Chloroform 50 1188Cyclohexane 300Dioxane 100 4200Ethylbenzene 100 3500Formic acid 5 1100Furfural 5 260Hydrogen chloride 5 4701Hydrogen cyanide 10 3.7Isopropyl alcohol 400 5045Toluene 100 5000Xylene 100 4300

• Examples:Examples:

Source: OSHASource: OSHA

Ethanol LD50 = 3450 (oral, mouse) 7060 (oral, rat) 1440 (intravenous, rat)



Toxic Substance Control Act (TSCA)Toxic Substance Control Act (TSCA)• TSCA TSCA (15 U.S.C. s/s 2601 et seq., 1976)(15 U.S.C. s/s 2601 et seq., 1976) is USEPA’s version of the is USEPA’s version of the

Food and Drug Act.Food and Drug Act.• Allows EPA to regulate the 75,000 chemical substances used in industry Allows EPA to regulate the 75,000 chemical substances used in industry

(including confidential materials)(including confidential materials)• TSCA requires extensive review before approval is given by USEPA to TSCA requires extensive review before approval is given by USEPA to

manufacture, import and sell a new (i.e., never before made) chemical in manufacture, import and sell a new (i.e., never before made) chemical in the USA.the USA.

• Under TSCA, USEPA can ban or restrict the import, manufacture and Under TSCA, USEPA can ban or restrict the import, manufacture and use of any chemicaluse of any chemical

• Under TSCA, anyone has a right and Under TSCA, anyone has a right and obligationobligation to report information to report information about new or alleged health/environmental effects caused by a chemical.about new or alleged health/environmental effects caused by a chemical.

• Section 5 of TSCA requires submitting a pre-manufacture Section 5 of TSCA requires submitting a pre-manufacture notice (PMN) to EPA 90 days before manufacturing or notice (PMN) to EPA 90 days before manufacturing or importing any new chemicalimporting any new chemical

• Electronic version of PMN form can be downloaded from EPA Electronic version of PMN form can be downloaded from EPA https://cdx.epa.gov/ssl/pmn/download.asp



Materials Hazards: FlammabilityMaterials Hazards: Flammability• A fire requires three things:A fire requires three things:

– A sufficient amount of fuelA sufficient amount of fuel– A sufficient amount of oxidantA sufficient amount of oxidant– A source of ignition (but not always - see autoignition)A source of ignition (but not always - see autoignition)

• Possible ignition sources includePossible ignition sources include– Electrical equipment such as motors, actuatorsElectrical equipment such as motors, actuators

• Usually specified as flame-proof or non-sparking when fuels are Usually specified as flame-proof or non-sparking when fuels are presentpresent

– Open flames from furnaces, incinerators & flare stacksOpen flames from furnaces, incinerators & flare stacks– Static electricityStatic electricity

• From any flow, hence pipes, vessels & flanges are always groundedFrom any flow, hence pipes, vessels & flanges are always grounded

– Miscellaneous sourcesMiscellaneous sources• Matches, lighters & mobile phones are usually bannedMatches, lighters & mobile phones are usually banned



Flammability DefinitionsFlammability Definitions• Flash pointFlash point

• The lowest temperature at which the material will ignite from an open The lowest temperature at which the material will ignite from an open flameflame

• Function of vapor pressure and flammability limitsFunction of vapor pressure and flammability limits

• Autoignition temperatureAutoignition temperature• Temperature at which the substance ignites in air spontaneouslyTemperature at which the substance ignites in air spontaneously• Indicates maximum temperature the material can be heated to in air, Indicates maximum temperature the material can be heated to in air,

e.g., in dryinge.g., in drying

• Flammability limitsFlammability limits• Highest and lowest concentrations in air at normal temperature and Highest and lowest concentrations in air at normal temperature and

pressure (ntp) at which a flame will propagate through the mixturepressure (ntp) at which a flame will propagate through the mixture• Vary widely for different materialsVary widely for different materials

• Data can be found in Materials Safety Data Sheets (MSDS) or safety Data can be found in Materials Safety Data Sheets (MSDS) or safety handbooks, e.g.:handbooks, e.g.:

Lewis, R.J., Sax’s Dangerous Properties of Industrial Materials, 10 th Edn., John Wiley & Sons Inc., New York, 1999. ($595 for 3 volumes, so check the library!)



Flame SuppressionFlame Suppression• Flame arrestors (flame traps) are specified on vent lines of equipment Flame arrestors (flame traps) are specified on vent lines of equipment

that contains flammable materials to prevent a flame from that contains flammable materials to prevent a flame from propagating back from the ventpropagating back from the vent

• Various proprietary designs are availableVarious proprietary designs are available

• Basic principle:Basic principle:– Provide high metal surface area to act as a sink for heat and free radicalsProvide high metal surface area to act as a sink for heat and free radicals

Enardo detonation flame arrestorsSource: Enardo LLCwww.Enardo.com



Materials Hazards: IncompatibilityMaterials Hazards: Incompatibility

• Mixtures of incompatible materials may undergo violent Mixtures of incompatible materials may undergo violent reaction (exothermic, temperature runaway)reaction (exothermic, temperature runaway)– Acids and basesAcids and bases– Acids and metalsAcids and metals– Fuels and oxidantsFuels and oxidants– Free radical initiators and epoxides, peroxides, unsaturates, …Free radical initiators and epoxides, peroxides, unsaturates, …

• Incompatibility with materials of construction can lead to Incompatibility with materials of construction can lead to loss of containmentloss of containment– Corrosion of vessels, internals, instrumentsCorrosion of vessels, internals, instruments– Softening of gaskets, seals, liningsSoftening of gaskets, seals, linings

• Materials incompatibility is one of the major sources of Materials incompatibility is one of the major sources of incidentsincidents



Materials Safety Data SheetsMaterials Safety Data Sheets• Material Safety Data Sheets (MSDSs) Material Safety Data Sheets (MSDSs)

must be provided to employees and must be provided to employees and customers by law in the U.S.A. customers by law in the U.S.A. (OSHA (OSHA Hazard Communication Standard 29 CFR Part Hazard Communication Standard 29 CFR Part 1910.1200)1910.1200)

• MSDS contains the information needed MSDS contains the information needed to begin analyzing materials and to begin analyzing materials and process hazardsprocess hazards

• Most MSDSs contain a disclaimer Most MSDSs contain a disclaimer stating that the user should also make stating that the user should also make their own evaluation of compatibility and their own evaluation of compatibility and fitness for usefitness for use



Materials Safety Data SheetMaterials Safety Data SheetExample: Ethylene DichlorideExample: Ethylene Dichloride

Material Safety Data Sheet 1,2-Dichloroethane, extra dry, water <50 ppm

ACC# 00220

Section 1 - Chemical Product and Company Identification

MSDS Name: 1,2-Dichloroethane, extra dry, water <50 ppm Catalog Numbers: AC326840000, AC326840010, AC326841000, AC326842500 Synonyms: Ethylene dichloride; 1,2-Ethylene dichloride; Glycol dichloride; EDC; sym-Dichloroethane; 1,2-Dichloroethane; Ethylene chloride. Company I dentification: Acros Organics N.V. One Reagent Lane Fair Lawn, NJ 07410 For information in North America, call: 800-ACROS-01 For emergencies in the US, call CHEMTREC: 800-424-9300

Section 2 - Composition, Information on Ingredients

CAS# Chemical Name Percent EI NECS/ ELI NCS

107-06-2 1,2-Dichloroethane >99.9 203-458-1

Hazard Symbols: T F Risk Phrases: 11 22 36/37/38 45

What’s in an MSDS?

• Chemical name

• Synonyms• Manufacturer

contact info• Composition

(Source: Fisher Scientific)




Section 3 - Hazards Identification

EMERGENCY OVERVIEW

Appearance: colorless liquid. Flash Point: 56 deg F. Warning! Flammable liquid and vapor. May cause central nervous system depression. May cause liver and kidney damage. May cause cancer based on animal studies. Causes eye and skin irritation. Causes respiratory tract irritation. I rritant. May be harmful if swallowed. Target Organs: Central nervous system, liver, eyes, skin. Potential Health Effects Eye: Causes eye irritation. Vapors may cause eye irritation. May cause chemical conjunctivitis and corneal damage. Skin: Causes skin irritation. May be absorbed through the skin. May cause irritation and dermatitis. May cause cyanosis of the extremities. I ngestion: May cause central nervous system depression, kidney damage, and liver damage. May cause gastrointestinal irritation with nausea, vomiting and diarrhea. May cause effects similar to those for inhalation exposure. May be harmful if swallowed. I nhalation: Inhalation of high concentrations may cause central nervous system effects characterized by nausea, headache, dizziness, unconsciousness and coma. Causes respiratory tract irritation. May cause liver and kidney damage. Aspiration may lead to pulmonary edema. Vapors may cause dizziness or suffocation. Can produce delayed pulmonary edema. Exposure to high concentrations may produce narcosis, nausea and loss of consciousness. May cause burning sensation in the chest. Chronic: Possible cancer hazard based on tests with laboratory animals. Prolonged or repeated skin contact may cause dermatitis. Prolonged or repeated eye contact may cause conjunctivitis. May cause liver and kidney damage. Effects may be delayed.

• Summary of major hazards




Section 4 - First Aid Measures

Eyes: Immediately flush eyes with plenty of water for at least 15 minutes, occasionally lifting the upper and lower eyelids. Get medical aid. Skin: Get medical aid. Flush skin with plenty of water for at least 15 minutes while removing contaminated clothing and shoes. Wash clothing before reuse. I ngestion: Never give anything by mouth to an unconscious person. Get medical aid. Do NOT induce vomiting. I f conscious and alert, rinse mouth and drink 2-4 cupfuls of milk or water. I nhalation: Remove from exposure and move to fresh air immediately. I f not breathing, give artificial respiration. I f breathing is difficult, give oxygen. Get medical aid. Do NOT use mouth-to-mouth resuscitation. Notes to Physician: Treat symptomatically and supportively.




Section 5 - Fire Fighting Measures

General I nformation: As in any fire, wear a self-contained breathing apparatus in pressure-demand, MSHA/NIOSH (approved or equivalent), and full protective gear. Vapors may form an explosive mixture with air. During a fire, irritating and highly toxic gases may be generated by thermal decomposition or combustion. Use water spray to keep fire-exposed containers cool. Flammable liquid and vapor. Approach fire from upwind to avoid hazardous vapors and toxic decomposition products. Vapors are heavier than air and may travel to a source of ignition and flash back. Vapors can spread along the ground and collect in low or confined areas. Extinguishing Media: For small fires, use dry chemical, carbon dioxide, water spray or alcohol-resistant foam. For large fires, use water spray, fog, or alcohol-resistant foam. Water may be ineffective. Do NOT use straight streams of water. Flash Point: 56e deg F ( 13.33 deg C) Autoignition Temperature: 775 deg F ( 412.78 deg C) Explosion Limits, Lower:6.2% Upper: 15.9% NFPA Rating: (estimated) Health: 2; Flammability: 3; Instability: 0

• Flammability data

• NFPA ratings




Section 6 - Accidental Release Measures

General I nformation: Use proper personal protective equipment as indicated in Section 8. Spills/ Leaks: Absorb spill with inert material (e.g. vermiculite, sand or earth), then place in suitable container. Avoid runoff into storm sewers and ditches which lead to waterways. Clean up spills immediately, observing precautions in the Protective Equipment section. Remove all sources of ignition. Use a spark-proof tool. Provide ventilation. A vapor suppressing foam may be used to reduce vapors.

Section 7 - Handling and Storage

Handling: Wash thoroughly after handling. Remove contaminated clothing and wash before reuse. Ground and bond containers when transferring material. Use spark-proof tools and explosion proof equipment. Avoid contact with eyes, skin, and clothing. Empty containers retain product residue, (liquid and/or vapor), and can be dangerous. Keep container tightly closed. Do not pressurize, cut, weld, braze, solder, drill, grind, or expose empty containers to heat, sparks or open flames. Use only with adequate ventilation. Keep away from heat, sparks and flame. Avoid breathing vapor or mist. Storage: Keep away from heat, sparks, and flame. Keep away from sources of ignition. Store in a tightly closed container. Keep from contact with oxidizing materials. Store in a cool, dry, well-ventilated area away from incompatible substances. Flammables-area. Storage under a nitrogen blanket has been recommended.




Section 8 - Exposure Controls, Personal Protection

Engineering Controls: Facilities storing or utilizing this material should be equipped with an eyewash facility and a safety shower. Use adequate general or local explosion-proof ventilation to keep airborne levels to acceptable levels. Exposure Limits

Chemical Name ACGI H NI OSH OSHA - Final PELs

1,2-Dichloroethane 10 ppm TWA 1 ppm TWA; 4 mg/m3 TWA 50 ppm IDLH

50 ppm TWA; 100 ppm Ceiling

OSHA Vacated PELs: 1,2-Dichloroethane: 1 ppm TWA; 4 mg/m3 TWA Personal Protective Equipment Eyes: Wear chemical goggles. Skin: Wear appropriate protective gloves to prevent skin exposure. Clothing: Wear appropriate protective clothing to prevent skin exposure. Respirators: A respiratory protection program that meets OSHA's 29 CFR 1910.134 and ANSI Z88.2 requirements or European Standard EN 149 must be followed whenever workplace conditions warrant a respirator's use.

• OSHA PEL data

• Required PPE




Section 9 - Physical and Chemical Properties

Physical State: Liquid Appearance: colorless Odor: chloroform-like pH: Not available. Vapor Pressure: 100 mm Hg @29 deg C Vapor Density: 3.4 (Air=1) Evaporation Rate:6.5 (Butyl acetate=1) Viscosity: Not available. Boiling Point: 81-85 deg C Freezing/ Melting Point:-35 deg C Decomposition Temperature:Not available. Solubility: Insoluble. Specific Gravity/ Density:1.25 (Water=1) Molecular Formula:C2H4Cl2 Molecular Weight:98.96




Section 10 - Stability and Reactivity

Chemical Stability: Stable at room temperature in closed containers under normal storage and handling conditions. Conditions to Avoid: Light, ignition sources, excess heat, electrical sparks. I ncompatibilities with Other Materials: Aluminum, bases, alkali metals, ketones, organic peroxides, nitric acid, strong oxidizing agents, strong reducing agents, liquid ammonia, amines. Hazardous Decomposition Products: Hydrogen chloride, phosgene, carbon monoxide, irritating and toxic fumes and gases, carbon dioxide. Hazardous Polymerization: Has not been reported.

• Known incompatible materials




Section 11 - Toxicological Information

RTECS#: CAS# 107-06-2: KI0525000 LD50/ LC50: CAS# 107-06-2: Draize test, rabbit, eye: 63 mg Severe; Draize test, rabbit, eye: 500 mg/24H Mild; Draize test, rabbit, skin: 500 mg/24H Mild; Inhalation, rat: LC50 = 1000 ppm/7H; Oral, mouse: LD50 = 413 mg/kg; Oral, rabbit: LD50 = 860 mg/kg; Oral, rat: LD50 = 670 mg/kg; Skin, rabbit: LD50 = 2800 mg/kg;<BR. Carcinogenicity: CAS# 107-06-2: ACGI H: A4 - Not Classifiable as a Human Carcinogen California: carcinogen; initial date 10/1/87 NIOSH: potential occupational carcinogen NTP: Suspect carcinogen OSHA: Possible Select carcinogen I ARC: Group 2B carcinogen Epidemiology: IARC Group 2B: Proven animal carcinogenic substance of pote ntial relevance to humans. IARC Group 2B: No data availa ble on human carcinogenicity, however sufficient evi dence of carcinogenicity in animals. Teratogenicity: See actual entry in RTECS for complete information. Reproductive Effects: No information found. Neurotoxicity: No information found. Mutagenicity: No information found. Other Studies: See actual entry in RTECS for complete information.

• Acute effects

• Chronic effects




Section 12 - Ecological Information

Ecotoxicity: Water flea Daphnia: 218mg/L; 48H; Bluegill/Sunfish: 430mg/L; 96H; Static Fathead Minnow: 136mg/L; 96H; Static No data available. Environmental: Terrestrial: Smaller releases on land will evaporate fairly rapidly. Larger releases may leach rapidly through sandy soil into groundwater. Aquatic: I f released to surface water, its primary loss will be by evaporation. The half-life for evaporation will depend on wind and mixing conditions and was of the order of hours in the laboratory. However a modeling study using the EXAMS model for a eutrophic lake gave a half-life of 10 days. Atmospheric: Will degrade by reaction with hydroxyl radicals formed photochemically in the atmosphere. Half-life over one month. Physical: Not expected to biodegrade or bioconcentrate. Other: For more information, see "HANDBOOK OF ENVIRONMENTAL FATE AND EXPOSURE DATA."

Section 13 - Disposal Considerations

Chemical waste generators must determine whether a discarded chemical is classified as a hazardous waste. US EPA guidelines for the classification determination are listed in 40 CFR Parts 261.3. Additionally, waste generators must consult state and local hazardous waste regulations to ensure complete and accurate classification. RCRA P-Series: None listed. RCRA U-Series: CAS# 107-06-2: waste number U077.




Section 14 - Transport Information

US DOT I ATA RID/ ADR I MO Canada

TDG

Shipping Name:

ETHYLENE DICHLORIDE

No

information available.

Hazard Class: 3

UN Number: UN1184

Packing Group: I I




Section 15 - Regulatory Information

US FEDERAL TSCA CAS# 107-06-2 is listed on the TSCA inventory. Health & Safety Reporting List CAS# 107-06-2: Effective Date: 6/1/87; Sunset Date: 6/1/97 Chemical Test Rules None of the chemicals in this product are under a Chemical Test Rule. Section 12b None of the chemicals are listed under TSCA Section 12b. TSCA Significant New Use Rule None of the chemicals in this material have a SNUR under TSCA. SARA CERCLA Hazardous Substances and corresponding RQs CAS# 107-06-2: 100 lb final RQ; 45.4 kg final RQ SARA Section 302 Extremely Hazardous Substances None of the chemicals in this product have a TPQ. SARA Codes CAS # 107-06-2: acute, chronic, flammable. Section 313 This material contains 1,2-Dichloroethane (CAS# 107-06-2, 99 9%),which is subject to the reporting requirements of Section 313 of SARA Title I I I and 40 CFR Part 373. Clean Air Act: CAS# 107-06-2 is listed as a hazardous air pollutant (HAP). This material does not contain any Class 1 Ozone depletors. This material does not contain any Class 2 Ozone depletors. Clean Water Act: CAS# 107-06-2 is listed as a Hazardous Substance under the CWA. CAS# 107-06-2 is listed as a Priority Pollutant under the Clean Water Act. CAS# 107-06-2 is listed as a Toxic Pollutant under the Clean Water Act. OSHA: None of the chemicals in this product are considered highly hazardous by OSHA. STATE CAS# 107-06-2 can be found on the following state right to know lists: California, New J ersey, Pennsylvania, Minnesota, Massachusetts. The following statement(s) is(are) made in order to comply with the California Safe Drinking Water Act: WARNING: This product contains 1,2-Dichloroethane, a chemical known to the state of California to cause cancer. California No Significant Risk Level: CAS# 107-06-2: 10 ug/day NSRL

• U.S. regulatory information




European/ International Regulations European Labeling in Accordance with EC Directives Hazard Symbols: T F Risk Phrases: R 11 Highly flammable. R 22 Harmful if swallowed. R 36/37/38 Irritating to eyes, respiratory system and skin. R 45 May cause cancer. Safety Phrases: S 45 In case of accident or if you feel unwell, seek medical advice immediately (show the label where possible). S 53 Avoid exposure - obtain special instructions before use. WGK (Water Danger/ Protection) CAS# 107-06-2: 3 Canada - DSL/ NDSL CAS# 107-06-2 is listed on Canada's DSL List. Canada - WHMI S This product has a WHMIS classification of B2, D2A, D2B. Canadian I ngredient Disclosure List CAS# 107-06-2 is listed on the Canadian Ingredient Disclosure List. Exposure Limits CAS# 107-06-2: OEL-ARAB Republic of Egypt:TWA 5 ppm (2 mg/m3) OEL-A USTRALIA:TWA 10 ppm (40 mg/m3) OEL-AUSTRIA:TWA 20 ppm (80 mg/m3) OEL -BELGIUM:TWA 10 ppm (40 mg/m3) OEL-DENMARK:TWA 1 ppm (4 mg/m3);Skin OEL-FINLAND:TWA 10 ppm (40 mg/m3);STEL 20 ppm (80 mg/m3);CAR OEL-FRAN CE:TWA 10 ppm (40 mg/m3) OEL-GERMANY;Carcinogen OEL-HUNGARY:STEL 4 m g/m3;Carcinogen OEL-J APAN:TWA 10 ppm (40 mg/m3) OEL-THE NETHERLANDS: TWA 50 ppm (200 mg/m3) OEL-THE PHILIPPINES:TWA 50 ppm (200 mg/m3) OE L-RUSSIA:TWA 10 ppm OEL-SWEDEN:TWA 1 ppm (4 mg/m3);STEL 5 ppm (20 mg/ m3);Skin;CAR OEL-SWITZERLAND:TWA 10 ppm (40 mg/m3);STEL 20 ppm (80 mg /m3) OEL-TURKEY:TWA 50 ppm (200 mg/m3) OEL-UNITED KINGDOM:TWA 10 ppm (40 mg/m3);STEL 15 ppm (60 mg/m3) OEL IN BULGARIA, COLOMBIA, J ORDAN, KOREA check ACGIH TLV OEL IN NEW ZEALAND, SINGAPORE, VIETNAM check A CGI TLV

• Foreign regulatory information




Section 16 - Additional Information

MSDS Creation Date: 10/19/1998 Revision #6 Date: 4/17/2002 The information above is believed to be accurate and represents the best information currently available to us. However, we make no warranty of merchantability or any other warranty, express or implied, with respect to such information, and we assume no liability resulting from its use. Users should make their own investigations to determine the suitability of the information for their particular purposes. In no event shall Fisher be liable for any claims, losses, or damages of any third party or for lost profits or any special, indirect, incidental, consequential or exemplary damages, howsoever arising, even if Fisher has been advised of the possibility of such damages.



Test: MSDSTest: MSDS

• A freight train has just derailed. It was pulling ten rail A freight train has just derailed. It was pulling ten rail tankers of ethylene dichloride from your plant. The local tankers of ethylene dichloride from your plant. The local fire chief calls the plant asking what should be done.fire chief calls the plant asking what should be done.

• What do you do?What do you do?



Role of MSDS in Process DesignRole of MSDS in Process Design

• Always collect MSDS of all components used in the process at as Always collect MSDS of all components used in the process at as early a stage as possibleearly a stage as possible

• Sources: manufacturers, manufacturer’s web sites, libraries, etc.Sources: manufacturers, manufacturer’s web sites, libraries, etc.

• Because of disclaimers, it is worth checking > 1 sourceBecause of disclaimers, it is worth checking > 1 source

• Good starting points are Good starting points are http://www.msdssearch.com/ or or http://www.siri.org/msds

• Use MSDS information to improve intrinsic safety of processUse MSDS information to improve intrinsic safety of process• Eliminate incompatible mixturesEliminate incompatible mixtures

• Substitute less hazardous chemicals when possible (e.g. toluene Substitute less hazardous chemicals when possible (e.g. toluene instead of benzene as solvent)instead of benzene as solvent)

• Ensure that design meets regulatory requirementsEnsure that design meets regulatory requirements• Vapor recoveryVapor recovery

• Other emissionsOther emissions



Design for Materials HazardsDesign for Materials Hazards• Substitution – use something less toxic and hazardousSubstitution – use something less toxic and hazardous

• ContainmentContainment• Sound design of plant and equipmentSound design of plant and equipment• For example, use welded joints instead of flangesFor example, use welded joints instead of flanges

• Prevention of releasesPrevention of releases• By design of equipment and disposal systemsBy design of equipment and disposal systems

• VentilationVentilation• Use open plant structure or engineered ventilation systemUse open plant structure or engineered ventilation system

• DisposalDisposal• Effective vent stacks and scrubbersEffective vent stacks and scrubbers• Collection and treatment of run-off water and liquid from relief systemsCollection and treatment of run-off water and liquid from relief systems

• Provision of emergency equipmentProvision of emergency equipment



Process HazardsProcess Hazards



Process Hazards: OverpressureProcess Hazards: Overpressure

• Occurs when mass, moles or energy accumulate in a Occurs when mass, moles or energy accumulate in a contained volume (or space with restricted outflow)contained volume (or space with restricted outflow)

• Rate of accumulation determines the pressure riseRate of accumulation determines the pressure rise

• Process controls may not be able to respond quickly Process controls may not be able to respond quickly enoughenough

• If pressure is not relieved by pressure safety valve then If pressure is not relieved by pressure safety valve then outcomes could includeoutcomes could include– Vessel ruptureVessel rupture– ExplosionExplosion– Other loss of containmentOther loss of containment

• See following lecture for design for overpressureSee following lecture for design for overpressure© 2012 G.P. Towler / UOP. For educational use in conjunction with Towler & Sinnott Chemical Engineering Design only. Do not copy


Process Hazards: Fires & ExplosionsProcess Hazards: Fires & Explosions

• A fire requires a flammable mixture and an ignition A fire requires a flammable mixture and an ignition sourcesource

• Fires in chemical plants can quickly lead to damage to Fires in chemical plants can quickly lead to damage to control systems and equipment, causing overpressure, control systems and equipment, causing overpressure, loss of containment and explosionsloss of containment and explosions

• Fire protection guidelines are given in several standards Fire protection guidelines are given in several standards (see Ch10)(see Ch10)– NFPA 30, API RP 2001, API Publ 2218NFPA 30, API RP 2001, API Publ 2218

• Legal requirements for fire protection are set by OSHA Legal requirements for fire protection are set by OSHA (29 CFR 1910 L)(29 CFR 1910 L)



Sources of IgnitionSources of Ignition

• Can you think of possible sources of ignition on a Can you think of possible sources of ignition on a chemical plant?chemical plant?– Sparking of electrical equipmentSparking of electrical equipment

• Motors, actuators, lighting, electric heaters, …Motors, actuators, lighting, electric heaters, …

– Process flamesProcess flames• Furnaces, flare stacks, incineratorsFurnaces, flare stacks, incinerators• These should always be sited well away from plant, usually upwindThese should always be sited well away from plant, usually upwind

– Static electricityStatic electricity• See API RP 2003 and NFPA 77See API RP 2003 and NFPA 77

– LightningLightning– Vehicles (engines, electrical systems and exhausts)Vehicles (engines, electrical systems and exhausts)– Portable electrical devicesPortable electrical devices– Welding and cutting equipmentWelding and cutting equipment– Miscellaneous sources (matches, lighters, etc. are usually Miscellaneous sources (matches, lighters, etc. are usually

banned)banned)



Process Electrical SystemsProcess Electrical Systems• The use of electrical equipment in chemical plants is The use of electrical equipment in chemical plants is

regulated by law (OSHA standard 29 CFR 1910.307) and by regulated by law (OSHA standard 29 CFR 1910.307) and by industry design codesindustry design codes

• National Electrical Code NFPA 70National Electrical Code NFPA 70• NFPA standards 496, 497, API RP 500, 505NFPA standards 496, 497, API RP 500, 505

• NFPA 70 defines classified areas in which flammable NFPA 70 defines classified areas in which flammable materials may be present at high enough concentrations to materials may be present at high enough concentrations to be ignitable (see Ch10)be ignitable (see Ch10)

• Specific precautions must be taken depending on the classificationSpecific precautions must be taken depending on the classification• Equipment must be designed and installed in accordance with codeEquipment must be designed and installed in accordance with code



Process Electrical SystemsProcess Electrical Systems• Codes should be consulted Codes should be consulted

before selecting equipment for before selecting equipment for use in classified areasuse in classified areas

• Codes also govern electrical Codes also govern electrical maintenance work (NFPA 70B). maintenance work (NFPA 70B). Companies usually have strict Companies usually have strict “Lock-out, tag-out” procedures “Lock-out, tag-out” procedures to prevent electric shock to prevent electric shock accidentsaccidents



Process Hazards: ExplosionsProcess Hazards: Explosions

• An explosion is the sudden, catastrophic release of An explosion is the sudden, catastrophic release of energy causing a pressure wave (blast wave)energy causing a pressure wave (blast wave)

• Explosions can be caused by ignition of a flammable Explosions can be caused by ignition of a flammable mixturemixture– LiquidLiquid

– VaporVapor

– Solid (e.g., finely dispersed dust)Solid (e.g., finely dispersed dust)

• Explosions can also be caused by release of thermal Explosions can also be caused by release of thermal energyenergy– Boiler ruptureBoiler rupture

– BLEVE (boiling liquid expanding vapor explosion)BLEVE (boiling liquid expanding vapor explosion)



Explosion DefinitionsExplosion Definitions• DeflagrationDeflagration

– Combustion zone propagates at (subsonic) flame speed, usually < 30 m/sCombustion zone propagates at (subsonic) flame speed, usually < 30 m/s– Pressure wave generated usually < 10 barPressure wave generated usually < 10 bar

– Principal heating mechanism is combustionPrincipal heating mechanism is combustion

• DetonationDetonation– Combustion zone propagates at supersonic velocity, 2000 – 3000 m/sCombustion zone propagates at supersonic velocity, 2000 – 3000 m/s– Pressure wave up to 20 barPressure wave up to 20 bar– Principal heating mechanism is shock compressionPrincipal heating mechanism is shock compression– Usually requires confinement or a high-intensity sourceUsually requires confinement or a high-intensity source– Deflagration can turn into detonation when propagating along a pipeDeflagration can turn into detonation when propagating along a pipe

• Expansion factorExpansion factor– Measure of the increase in volume resulting from combustionMeasure of the increase in volume resulting from combustion– E = (molar density of reagents)/(molar density of products)E = (molar density of reagents)/(molar density of products)– Maximum value of E is for adiabatic combustionMaximum value of E is for adiabatic combustion

• Flame speedFlame speed– The rate of propogation of a flame front through a flammable mixture, with respect to a fixed The rate of propogation of a flame front through a flammable mixture, with respect to a fixed

observerobserver



Explosivity PropertiesExplosivity Properties

Upper LowerHydrogen H2 4.0 75 54 22.1 2318 6.9 400

Methane CH4 5.0 15 10 2.8 2148 7.5 601

Ethane C2H6 3.0 12.4 6.3 3.4 2168 7.7 515

Propane C3H8 2.1 9.5 4.5 3.3 2198 7.9 450

n-Butane C4H10 1.8 8.4 3.5 3.3 2168 7.9 405

Pentane C5H12 1.4 7.8 2.9 3.4 2232 8.1 260

Hexane C6H14 1.2 7.4 2.5 3.4 2221 8.1 225

Heptane C7H16 1.1 6.7 2.3 3.4 2196 8.1 215

Acetylene C2H2 2.5 80 9.3 14.8 2598 8.7 305

Ethylene C2H4 2.7 36 7.4 6.5 2248 7.8 490

Propylene C3H6 2.4 10.3 5 3.7 2208 7.8 460

Butylene C4H8 1.7 9.7 3.9 3.8 2203 7.9 385

Benzene C6H6 1.3 7.9 3.3 5 2287 8.1 560

Cyclohexane C6H12 1.3 8.0 2.7 4.2 2232 8.1 245

Autoignition temperature

(ºC)Formula

Flammability Limits (vol%)Fuel

Vol% gas at max flame

speed

Adiabatic flame Temp

(K)

Expansion factor

Maximum flame speed

(m/s)

Dugdale, D. An introduction to Fire Dynamics, Wiley, New York, 1985



Explosions: Design ImplicationsExplosions: Design Implications

• Design to prevent explosions from happeningDesign to prevent explosions from happening

• Prevent formation of explosive mixtures whenever Prevent formation of explosive mixtures whenever possiblepossible– Operate outside flammability envelopeOperate outside flammability envelope

• Consider confined explosion as a pressure relief Consider confined explosion as a pressure relief scenario and ensure that PRV is sized to allow adequate scenario and ensure that PRV is sized to allow adequate relief load to prevent detonationrelief load to prevent detonation

• Use flame suppressors to prevent deflagration from Use flame suppressors to prevent deflagration from propagating into detonationpropagating into detonation



Process Hazards: Loss of ContainmentProcess Hazards: Loss of Containment

• The primary means of protecting the public from toxic chemicals is The primary means of protecting the public from toxic chemicals is containment by the plant itselfcontainment by the plant itself

• Loss of containment can occur due to:Loss of containment can occur due to:– Pressure reliefPressure relief

– Operator error (e.g. leaving a sample point open)Operator error (e.g. leaving a sample point open)

– Poor maintenance proceduresPoor maintenance procedures• Failure to drain and purge properlyFailure to drain and purge properly• Failure to put everything back together properlyFailure to put everything back together properly

– Leaks from degraded equipmentLeaks from degraded equipment• CorrosionCorrosion• Damaged seals, gasketsDamaged seals, gaskets

• These are mostly operational issues, but design may need to provide These are mostly operational issues, but design may need to provide for secondary containment if the potential impact of a release is highfor secondary containment if the potential impact of a release is high



Process Hazards: NoiseProcess Hazards: Noise• Chemical plants can be very noisy, especially compressors, turbines, Chemical plants can be very noisy, especially compressors, turbines,

motors and solids handlingmotors and solids handling

• Chronic effects include permanent damage to hearingChronic effects include permanent damage to hearing

• Sound is measured in decibels, defined by:Sound is measured in decibels, defined by:

(Note: log scale)(Note: log scale)

• Ear protection should be required in areas where noise > 80 dBEar protection should be required in areas where noise > 80 dB

• Permanent damage can be caused by noise > 85 dBPermanent damage can be caused by noise > 85 dB

dB

102

PapressuresoundRMSlog20levelSound

510



Questions ?Questions ?


3.1 safety

Documents