hexavalent chromium presentation
DESCRIPTION
cr6TRANSCRIPT
HEXAVALENT CHROMIUMA Standard In Review
Paul Watson
CIH, CSP,
ATC Associates
Adopted from presentation developed under the Susan Harwood Grant # 46E6 – HT34
Background Information
Chromium is a metal that exists in several oxidation or valence states, ranging from chromium (-II) to chromium (+VI).
Chromium compounds are very stable in the trivalent state and occur naturally in this state in ores such as ferrochromite, or chromite ore.
Chrome III is an essential nutrient for maintaining blood glucose levels
The hexavalent, Cr(VI) or chromate, is the second most stable state. It rarely occurs naturally; most Cr(VI) compounds are man made.
What is Hexavalent Chromium?(“chrome 6”)
A toxic form of chromium metal, generally man-made.
Used in many industrial applications, primarily for its anti-corrosive properties.
Can be generated during welding on stainless steel or metal structures coated with chromate paint.
Used in electroplating (chrome plating)
Product Types of Hexavalent Chromium Chemicals
pigments in paints, inks, and plastics
lead chromate (chrome yellow, chrome green, molybdenum orange) zinc chromate barium chromate calcium chromate potassium dichromate sodium chromate
anti-corrosion coatings (chrome plating, spray coatings)
chromic trioxide (chromic acid) zinc chromate barium chromate calcium chromate sodium chromate strontium chromate
stainless steel and other high chromium alloys
hexavalent chromium (when cast, welded, or torch cut)
textile dyesammonium dichromate potassium chromate potassium dichromate sodium chromate
wood preservation chromium trioxide
leather tanning ammonium dichromate
Products that contain hexavalent chromium
Chrome plating or electroplating
Welding or cutting on stainless steel or grinding on objects painted with chromate paint
Painting:
Auto body repair Aircraft spray painting
Common jobs with potential chrome 6 exposure
Chromium dye and catalyst production
Glass manufacturing
Plastic colorant production
Construction
Traffic painting Refractory brick restoration
Paint removal from bridges
Hazardous waste site work
Other jobs with potential chrome 6 exposure
bridge work
Road strip painting
Health Effects
Ingestion Hazards Erosive to stomach, Hemorrhaging and death are likely
Eyes Direct eye contact with chromic acid or chromate dusts can
cause permanent eye damage.
Respiratory Tract Hexavalent chromium can irritate the nose, throat, and lungs.
Repeated or prolonged exposure can damage the mucous membranes of the nasal passages and result in ulcers.
Skin Prolonged skin contact can result in dermatitis and skin ulcers.
Some workers develop an allergic sensitization to chromium. In sensitized workers, contact with even small amounts can cause a serious skin rash.
Health Effects
Cancer
Chrome VI is classified as a known human carcinogen
Hexavalent chromium is considered a potential lung carcinogen.
Studies of workers in the chromate production, plating, and pigment industries consistently show increased rates of lung cancer.
Insoluble forms such as zinc chromate are the most potent
20 year cancer latency
Greater Risk Than Asbestos
Cancer risk from Cr (VI) at new PEL is higher than asbestos and benzene risk at their PELs
Asbestos: 6.7 deaths per 1000 workers
Benzene: 10 deaths per 1000 workers
Chrome VI: 10-45 excess lung cancer deaths per 1000 workers for 45 years of exposure at new PEL of 5 ug/m3
Major Health Effects
Lung cancer
Nasal septum ulcers or perforations
Bronchitis or asthma
Perforation of the nasal septum from chrome 6 exposure
X-ray showing lung cancer
Chrome 6 effects on skin
Skin ulcers
Allergic and irritant contact dermatitis
“Chrome hole” on finger
Skin effects are not likely in welding, but can occur in electroplating or painting
New Cr VI OSHA Standard
Suit by Public Citizen Health Research Group; Paper, Allied Industrial, Chemical, and Energy Workers Union
4/2/2003 - 3rd Circuit Court of Appeals rules standard by 1/18/2006
2/28/2006 - Final Rule published 20 or more employees - November 27, 2006. 19 or fewer employees - May 30, 2007. For all employers, engineering controls May 31, 2010. OSHA and the Steelworkers engaged in settlement
agreement required engineering controls on an expedited schedule (by December 31, 2008), but will have relief from certain respirator requirements in the interim.
Portland Cement is exempted.
General Industry 29 CFR 1910.1026
Scope Definitions Permissible exposure limit (PEL). Exposure determination. Regulated areas Methods of compliance Respiratory protection Protective work clothing and equipment Hygiene areas and practices Housekeeping Medical surveillance Communication Recordkeeping Dates
Construction Industry 29 CFR 1926.1126
No definition of a Regulated Area
Notify Employee’s within 5 days of receipt of results
15 days General Industry
Definitions
Action level - 2.5 µg/m³ (8-hour TWA).
Permissible Exposure Limit - 5 µg/m³ (8-hour TWA).
This has been lowered from the past level of 52 micrograms per cubic meter of air (52 µg/m³).
But it is higher than the original proposed PEL of 1ug/m3
Two limits for Chrome 6 in air
5 micrograms per
cubic meterin the air
2.5 micrograms per cubic meter
in the air
Permissible Exposure Limit (PEL)
8-hour average exposure limit
Action Level (AL)
half of the PEL
Comparison of OELs
Potential Sources
Welding
Stainless steel
Carbon steel (confined spaces)
Aircraft Painting
Priming with zinc chromate primers
Removing primers
Chrome Plating
Chromic Acid
Excluded
Portland Cement
Pesticide Application (Wood Preservative)
Welding
Nearly half the workers covered under the new standard are welders
Chromium in steel is oxidized to Cr VI by high welding temperatures
6,000 - 8,000° C for the SMAW, GTAW, GMAW, FCAW and SAW processes
The hotter the process and the more oxygen that is present, more fume is generated
Stick welding: 50% of Cr produced is Cr VI
TIG & MIG 4% of total Cr produced is Cr VI
Stainless steel has between 10.5% - 27% chromium
Painting
Aluminum Primers
Zinc Chromate and Strontium Chromate• Also present in in adhesives/sealants
Chromates required for proper adhesion
Chromate free primers are being researched
Exposure occurs during spray painting• Special sample handling required
Exposures occur during sanding and bead blasting
Plating and Chromic Acid
Chrome Plating produces chromic acid mists over the plating tanks.
The mist is created by the electroplating currents causing bubbles in the solution. The bubbles pop at the surface and create a mist over the tank
Tank ventilation systems are common, but are frequently deficient.
Other chromic acid exposures occur from chromic acid solution preparations.
Chromic acid flakes are dumped mixed into solutions for many chemical processes
Exposure Determination
Each employer who has a workplace or work operation covered by this section shall determine the 8-hour TWA exposure for each employee exposed to chromium (VI).
This determination shall be made in accordance with either of the following methods:
Scheduled Monitoring Option
Performance-oriented Option
Objective data means:
Information such as air monitoring data from industry-wide surveys; or
Calculations based on the composition or chemical and physical properties of a substance
How do you Sample?
Air sampling
OSHA ID-215
Ship within 24 hours
Note type of operation
In breathing zone
Under welding visor
Surfaces
W-4001
Target value is 0.050 µg/100 cm2
Exposure Determination
If samples show < Action Level
May discontinue monitoring If samples show ≥ Action Level
Periodic monitoring every six months If samples show ≥ Permissible Exposure Level
Periodic monitoring every three months Additional monitoring where process has changed
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Notification of air monitoring results
If air monitoring shows chrome 6 levels in the air exceed the PEL we must:
- Notify you within 5 days in construction or within 15 days in general industry
- Describe to you in writing what corrective actions we will take to reduce your exposure below the PEL.
Skin Sampling
1910.1026 does not require skin sampling! The final rule requires the employer to provide appropriate protective clothing and equipment where a hazard is present or is likely to be present from skin or eye contact with Cr (VI), but does not specify criteria to be used for determining when a hazard is present or is likely to be present”. One of the tools which the employer can use is skin sampling. But, OSHA is not aware of any evidence that would allow establishment of a threshold concentration of Cr(VI) below which adverse skin or eye effects would not occur.
The interpretation letter on the OSHA Web page states “To determine whether there is a hazard (or potential hazard) from skin or eye contact with chromium (VI) in a particular workplace, the employer should use appropriate expertise in assessing hazards. (See non-mandatory appendices providing guidance on hazard assessment in 29 CFR 1910 Subpart I Appendix B; 29 CFR 1915 Subpart I Appendix A). The recommended approach involves a walkthrough survey to identify sources of chromium (VI) hazards to workers. Also recommended are reviews of occupational illness records to determine if past skin exposures have been recorded or if skin conditions were reported which may have been linked to chromium (VI) exposures, as well as a review of any exposure determination(s) for operations involving chromium (VI)”.
Methods of Compliance
Use engineering and work practice controls to reduce and maintain employee exposure to or below the PEL. When not sufficient enough, Use of respiratory protection in
Addition.
If exposure above the PEL is less than 30 days per year, Use of respiratory protection alone to comply.
No rotation of employees to different jobs to achieve compliance with the PEL.
Welding Controls
Fume extractor for stick welding on stainless steel
Use MIG/TIG welding on stainless steel whenever possible
Fume extractor for enclosed welding on any kind of steel
Weld using smaller rods
Weld using lower amperage (temperature)
Keep head out of rising plume
When welding, keep your head out of the welding plume.
Welding work practices
Use available local exhaust ventilation at all times.
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Welding in confined spaces
Welding on stainless steel in a confined space will most likely require both exhaust ventilation and the use of respirators.
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Painting Controls
Substitute with non-Cr VI paint, if possible
Conduct spray painting in an extremely well-designed and maintained booth. (Think of controlling lead-based spray paint exposures, but having to control 10 times better.)
Some grinders have a ventilated shroud on the grinder or needle gun, others may also have a perforated grinder disk
Airline respirators
Use Paint strippers to eliminate airborne exposures
Personal Protective Equipment
When exposure to hazards cannot be engineered completely out of normal operations or maintenance work, and when safe work practices cannot provide sufficient additional protection, a further method of control is using protective clothing or equipment.
1910.1026(f)(1)(ii) Where painting of aircraft or large aircraft parts is performed in the aerospace industry, the employer shall use engineering and work practice controls to reduce and maintain employee exposure to chromium (VI) to or below 25 µg/m3. The employer shall supplement such engineering and work practice controls with the use of respiratory protection that complies with the requirements of paragraph (g) of this section to achieve the PEL.
Protective Work Clothing and Equipment
Where a hazard is present or is likely to be present from skin or eye contact with chromium (VI);
Provide appropriate personal protective clothing and equipment at no cost to employees, and
Ensure that employees use such clothing and equipment.
All protective clothing and equipment contaminated with chromium (VI) must be:
Removed at the end of the work shift or at the completion of their tasks, whichever comes first;
Stored and transported in sealed, properly labeled,
impermeable bags or other closed, impermeable containers.
Protective Work Clothing and Equipment
No employees may remove chromium (VI)-contaminated protective clothing or equipment from the workplace, except for those employees whose job it is to launder, clean, maintain, or dispose of such clothing or equipment.
All protective clothing and equipment required by this section shall be cleaned, laundered, repaired and replaced as needed to maintain its effectiveness.
The removal of chromium (VI) from protective clothing and equipment by blowing, shaking, or any other means that disperses chromium (VI) into the air or onto an employee's body is prohibited.
U se w here skin or eye contact w ith chrome 6 w il l occur or i s l ikely to occur.
N ormal w elding P P E (w elding helmet, gloves and welding leathers ) i s O .K . for welders
R emove all P P E w hen w ork shi ft or task is completed. D on’t w ear or take it home.
Protective Work Clothing and Equipment
Don’t remove chrome 6 dust or residue from clothing by blowing, shaking, or any other means that disperses the dust into the air or onto the body.
Protective Work Clothing Use
Don’t use compressed air to clean clothing
Don’t shake out dusty coveralls or clothes
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Laundering and Cleaning PPE
Use of outside service to launder or replace all protective clothing and other protective equipment
Put your contaminated PPE in a sealed bag for laundering or repair
The person doing these tasks must be informed of the hazards of chrome 6
Types of Respirators for Chrome 6
In some jobs involving chrome 6 exposure, you may need to wear a respirator.
The type of respirator worn depends on the amount of chrome 6 in the air.
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Respiratory Protection
Minimum N-95
Based on airborne exposure
Hygiene Areas and Practices
Where protective clothing and equipment is required, the employer shall provide change rooms. Separate storage for contaminated and clean clothes
Where skin contact with chromium (VI) occurs, the employer shall provide washing facilities: Such facilities shall be in near proximity to the worksite and shall
be so equipped as to enable employees to remove such substances. MUST BE WATER BASED CLEANING SYSTEM.
Washing facilities shall be maintained in a sanitary condition. Use of these facilities when necessary shall be enforced.
29 CFR 1926.1126(h)
Hygiene Areas and Practices
Change rooms – separate storage facilities for PPE and street clothes
Washing facilities
Be sure to wash hands and face:
at the end of the work shift
before eating, drinking, smoking, chewing tobacco or gum, applying cosmetics, or using the toilet
If you have a job where chrome 6 can get on your skin or in your eyes, the employer must provide the following:
Keep all surfaces as free as practicable of accumulations of dust containing chrome 6.
Promptly clean up all spills and releases of chrome 6 containing materials
Use a HEPA vacuum or wet methods for cleaning areas contaminated with dust or other materials containing chrome 6
Dispose of chrome 6 contaminated waste in labeled & sealed bags or containers.
Housekeeping
Medical Surveillance
A medical examination consists of: A medical and work history;
A physical examination of the skin and respiratory tract.
Information to PLHCP
Employer shall obtain written opinion within 30 days containing: Any detected conditions placing employee at increased risk of
material impairment from Cr+6 exposure
Limitations of exposure or use of PPE
Statement that Physician or other Licensed Health Care Professional’s (PLHCP’s) explained results of exam to employee
Employer shall provide copy to employee within 2 weeks29 CFR 1926.1126(i)
Any employee exposed at or above the action level for 30 or more days per year.
Any employee experiencing signs or symptoms of chrome 6 exposure.
Any employee exposed in an uncontrolled release of large amounts of chrome 6 in any form.
Who Must Be Provided Medical Exams?
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Medical Exams (cont.)
Are done by or under the supervision of a physician or other licensed health care professional
Provided at no cost to you at a reasonable place and time
Medical Exams will do the following:
Determine if you can be exposed to Chrome 6 without experiencing adverse health effects.
Identify chrome 6 related adverse health effects so that appropriate measures can be taken.
Determine your fitness to use respirators.
Medical and work history
Cr(VI) exposure (past, present, future)
History of respiratory system dysfunction
History of asthma, dermatitis, skin ulceration or nasal system perforation
Smoking status and history
Physical examination, with emphasis on the respiratory tract and skin
Any additional tests deemed appropriate by the healthcare professional
Medical exams will include the following:
Within 30 days after initial assignment and annually thereafter
Within 30 days after a doctor recommends additional examinations
When employees shows signs or symptoms of Chrome 6 exposure
Within 30 days after exposure during an emergency
At the termination of employment
Medical Exams are offered:
After your medical exam the health care professional will give a written medical opinion to us within thirty days
Specific findings or diagnoses unrelated to occupational exposure to chrome 6 will be not revealed to us
Healthcare professional’s written medical opinion
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Communication of Hazards
The employer shall ensure that each employee can demonstrate knowledge of at least the following:
The contents of this section; and
The purpose and a description of the medical surveillance program.
Hazard Communication
29 CFR 1926.1126(j)
WA State Department of Labor and Industries, Video
Six Modules
Can down load for free from:
http://www.lni.wa.gov/Safety/Topics/AtoZ/Grants/awardees/UWHexavalent/HexChromeVideos.asp
Background Information
OSHA has determined that the PEL of 5 µg/m3 is technologically feasible for all affected welding job categories
OSHA has concluded that no carbon steel welders are exposed to Cr(VI) above 5 µg/m3, with the exception of a small portion of workers welding on carbon steel in enclosed and confined spaces.
Many welding processes, such as tungsten-arc welding (TIG) and submerged arc welding (SAW), already achieve Cr(VI) exposures below the PEL because they inherently generate lower fume volumes.
Inspection Activity
Hexavalent chromium inspections
May 30, 2006 to December 31, 2007
78 Fed inspections with violations of 1910.1026
72 inspections in General Industry
6 inspections in Construction
0 inspections in Shipyards
# of total Cr(VI) violations = 155
$ amount of total current penalties = $157,534.00
Inspection Activity
72 inspections in General Industry with 1910.1026 violations Breakdown of these 72 employers by SIC code:
• (7) ---- 3471 Electroplating, Plating, Polishing, Anodizing, and Coloring • (5) ---- 3499 Fabricated Metal Products, Not Elsewhere Classified • (5) ---- 3443 Fabricated Plate Work (Boiler Shops) • (3) ---- 3444 Sheet Metal Work • (3) ---- 3441 Fabricated Structural Metal • (3) ---- 3325 Steel Foundries, Not Elsewhere Classified • (2) ---- 7699 Repair Shops and Related Services, Not Elsewhere Classified • (2) ---- 3743 Railroad Equipment • (2) ---- 3728 Aircraft Parts and Auxiliary Equipment, Not Elsewhere Classified • (2) ---- 3559 Special Industry Machinery, Not Elsewhere Classified • (2) ---- 3535 Conveyors and Conveying Equipment • (2) ---- 3442 Metal Doors, Sash, Frames, Molding, and Trim Manufacturing • (2) ---- 2521 Wood Office Furniture • (1) ---- etc., for (32) other SIC codes
Inspections
List of the 5-most cited Cr(VI) violations:
1910.1026(d)(1) - didn't determine exposure
1910.1026(c) - exposure exceeded PEL
1910.1026(e)(1) - no regulated area
1910.1026(k)(1)(i)(A) - no medical surveillance
1910.1026(l)(2)(i)(A) - no employee knowledge of standard
Inspection Procedures
Conclusions
The Hexavalent Chromium standard can be a problem. It is a comprehensive vertical standard with many requirements, if it applies to you
Recommendations
Evaluate your Workplace • (Stainless Steel is the trigger)
Conduct sampling
Evaluate exposure controls
Implement the full 1910.1026 standard
Self check using the CPL
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