The National Institute for Occupational Safety and Health (NIOSH) recommends that as a prudent measure, epichlorohydrin be handled in the workplace as if it were a human carcinogen. This recommendation is based primarily on two recent studies: a long term epidemiologic study showing significant increase in respiratory cancer deaths of exposed workers, and an inhalation study showing an increase in nasal carcinomas in rats. In addition, cytogenic studies of human peripheral lymphocytes have shown a highly significant increase in chromosome abnormalities in exposed workers. Pending further evaluation of its carcinogenic potential, NIOSH believes it would be prudent to minimize occupational exposure to epichlorohydrin.
NIOSH has prepared this Bulletin to advise you of these recent studies, their implications for occupational health, and precautions for handling products containing epichlorohydrin. We request that producers, distributors, and users transmit this information to their customers and employees, and that professional associations and unions inform their members.
In September 1976, NIOSH recommended an occupational exposure limit of 2 mg/cu m of air (approximately 0.5 ppm) determined as a time-weighted average (TWA) concentration for up to a 10 hour work day in a 40 hour work week, and a ceiling concentration standard of 19 mg/cu m (approximately 5 ppm) as determined by a sampling time of 15 minutes.2 After a comprehensive review of the literatures NIOSH concluded that risks from exposure to epichlorohydrin may include carcinogenesis, mutagenesis and sterility, as well as damage to the kidneys, liver, respiratory tract, and skin. Since most of the evidence on adverse effects of epichlorohydrin was obtained from animal experiments which were inadequate to determine scientifically acceptable exposure limits, the 1976 NIOSH recommendation was based on professional judgement which quantitatively considered the cumulative toxic effects.
According to the NIOSH National Occupational Hazard Survey (NOHS),3 an estimated 85,000 workers are potentially exposed to epichlorohydrin in the workplace. Table 1 lists occupations and industries in which a potential exists for exposure to epichlorohydrin. The NOHS survey data were collected during 1972 to 1974 from a sample of approximately 5,000 businesses employing nearly 900,000 workers. 1970 Census figures were used in extrapolating the sample data to the working population employed in industries covered by the Occupational Safety and Health Act of 1970. The potential exposure estimates include data on actual observations of the use of the specific chemical or the use of a trade name product known to contain the chemical as well as additional observations of generic formulations (trade name products suspected of containing the chemical).
Occupations a | assemblers; miscellaneous specified machine operatives; aircraft machinists; construction and maintenance painters; miscellaneous operatives; chemists; mining operatives; painters of manufactured articles; sheetmetal workers and tinsmiths; pattern and model matters except paper |
Industries b | chemicals and allied products; transportation equipment; instruments and related products; transportation by air; electrical equipment and supplies; special trade contractors; miscellaneous repair services; rubber and plastics not elsewhere classified; machinery, except electrical; stone, clay, and glass products |
The Dow Chemical Company has informed NIOSH that it is currently conducting a mortality study of workers engaged in the manufacture and conversion of epichlorohydrin.10 Dow estimates that the results will be made available November, 1978.
Further information on previous studies that investigated the other evidence relating to carcinogenicity of epichlorohydrin can be found in the NIOSH epichlorohydrin criteria document.2,13
In 1976, Sram et al.15 found chromosome abnormalities in human peripheral lymphocytes exposed in vitro to epichlorohydrin. They concluded that a genetic risk for man exists following exposure to epichlorohydrin. A quantitative risk was not estimated.
Route of Exposure | Effect |
dermal | burning sensation, redness, swelling, red papules, itching, blisters, skin erosion, enlarged lymph nodes |
inhalation | burning of the eyes, nose and throat; cough; chest congestion; running nose; eye tenderness; headache followed by nausea; vomiting; facial swelling; dyspnea |
Exposure to epichlorohydrin has been shown to induce sterility in rats,2 and a fertility study has been conducted in male workers exposed to epichlorohydrin.17 While the study concluded that exposure to epichlorohydrin did not decrease sperm counts or affect hormonal activity in the workers, the data were not analyzed statistically.
[signature] J. Michael Lane, M.D. Acting Director
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Initial and routine employee exposure surveys should be made by competent industrial hygiene and engineering personnel. These surveys are necessary to determine the extent of employee exposure and to ensure that controls are effective.
The NIOSH Occupational Exposure Sampling Strategy Manual,2 may be helpful in developing efficient programs to monitor employee exposures to epichlorohydrin. The manual discusses determination of the need for exposure measurements selection of appropriate employees for exposure evaluation and selection of sampling times.
Employee exposure measurements should primarily consist of 8-hour TWA (time-weighted average) exposure estimates calculated from personal or breathing zone samples (air that would most nearly represent that inhaled by the employees). In addition, short term samples should be taken during periods of maximum expected exposure by using all available knowledge regarding the area, employee work procedures, and process. Area and source measurements may be useful to determine problem areas, processes, and operations.
The most effective control of epichlorohydrin where feasible, is at the source of contamination by enclosure of the operation and/or local exhaust ventilation. Guidelines for selected processes and operations can be found in the NIOSH Recommended Industrial Ventilation Guidelines.3
If feasible, the process or operation should be enclosed with a slight vacuum so that any leakage will result in the flow of external air into the enclosure.
The next most effective means of control would be a well designed local exhaust ventilation system that physically encloses the process as much as possible, with sufficient capture velocity to keep the contaminant from entering the work atmosphere.
To ensure that ventilation equipment is working properly, effectiveness (e.g., air velocity, static pressure or air volume) should be checked at least every three months. System effectiveness should be checked soon after any change in production, process, or control which might result in significant increases in airborne exposure to epichlorohydrin.
A third alternative is the isolation of employees. It frequently involves the use of automated equipment operated by personnel observing from a closed control booth or room. The control room is maintained at a greater air pressure than that surrounding the process equipment so that air flow is out of, rather than into, the room. This type of control will not protect those employees that must do process checks, adjustments maintenance and related operations.
The least preferred method is the use of personal protective equipment. This equipment which may include respirators goggles, gloves, etc., should not be used as the only means to prevent or minimize exposure during routine operations.
Exposure to epichlorohydrin should not be controlled with the use of respirators except:
Only respirators approved by the National Institute for Occupational Safety and Health (NIOSH) under the provisions of Federal regulations 30 CFR 11 should be used. Refer to Cumulative Supplement June 1977, NIOSH Certified Equipment4 for a listing of NIOSH-approved respirators. Note that the use of faceseal coverlets or socks with respirators voids NIOSH approvals.
Quantitative faceseal fit test equipment (such as sodium chloride, dioctyl phthalate, or equivalent) should be used. Refer to NIOSH's A Guide to Industrial Respiratory Protection5 for guidelines on appropriate respiratory protection programs.
In addition, proper maintenance procedures, good housekeeping in the work area, and employee education are all vital aspects of a good control program. Employees should be informed as to the nature of the hazard, its control, and appropriate personal hygiene procedures.
GPO publications must be ordered from: | Superintendent of Documents U.S. Government Printing Office Washington, D.C. 20402 |
Reference #4 can be ordered from: | Publications Dissemination, DTS NIOSH 4676 Columbia Parkway Cincinnati, Ohio 45226 |
1-Chloro-2,3-epoxypropane | Epichlorohydrin |
3-Chloro-1,2-epoxypropane | a-Epichlorohydrin |
3-Chloro-1,2-propylene oxide | 1,2-Epoxy-3-chloropropane |
(Chloromethyl)ethylene oxide | 2,3-Epoxypropyl chloride |
(Chloromethyl)oxirane | Glycerol epichlorohydrin |
2-Chloromethyl oxyrane | Glycidyl chloride |
3-Chloropropene-1,2-oxide | Oxirane, (chloromethyl)- |
Chloropropylene oxide | Oxirane, 2-(Chloromethyl)- |
y-Chloropropylene oxide | Propane, 1-chloro-2,3-epoxy- |
ECH | SKEKhG |
ECHH |
1. Chloroprene | January 20, 1975 | |
2. Trichloroethylene (TCE) | June 6, 1975 | |
3. Ethylene Dibromide (EDB) | July 7, 1975 | |
4. Chrome Pigment | June 24, 1975 October 7, 1975 October 8, 1976 | |
5. Asbestos - Asbestos Exposure during Servicing of Motor Vehicle Brake and Clutch Assemblies | August 8, 1975 | |
6. Hexamethylphosphoric Triamide (HMPA) | October 24, 1975 | |
7. Polychlorinated Biphenyls (PCBS) | November 3, 1975 August 209 1976 | |
8. 4,4'-Diaminodiphenylmethane (DDM) | January 30, 1976 | |
9. Chloroform | March 15, 1976 | |
10. Radon Daughters | May 11, 1976 | |
11. Dimethylcarbamoyl Chloride (DECC) Revised | July 7, 1976 | |
12. Diethylcarbamoyl Chloride (DECC) | July 7. 1976 | |
13. Explosive Azide Hazard | August 16, 1976 | |
14. Inorganic Arsenic - Respiratory Protection | September 27,1976 | |
15. Nitrosamines in Cutting Fluids | October 6, 1976 | |
16. Metabolic Precursors of a Known Human Carcinogen, Beta-Naphthylamine | December 17, 1979 | |
17. 2-Nitropropane | April 25, 1977 | |
18. Acrylonitrile | July 1, 1977 | |
19. 2,4-Diaminoanisole in Hair and Fur Dyes | January 13, 1978 | |
20. Tetrachloroethylene (Perchloroethylene) | January 20, 1978 | |
21. Trimellitic Anhydride (TMA) | February 3, 1978 | |
22. Ethylene Thiourea (ETU) | April 11, 1978 | |
23. Ethylene Dibromide and Disulfiram Toxic Interaction | April 11, 1978 | |
24. Direct Black 38, Direct Blue 6, and Direct Brown 95 Benzidine Derived Dyes | April 17, 1978 | |
25. Ethylene Dichloride (1,2-Dichloroethane) | April 19, 1978 | |
26. NIAXI Catalyst ESN | May 22, 1978 | |
27. Chloroethanes - Review of Toxicity | August 21, 1978 | |
28. Vinyl Halides - Carcinogenicity | September 21,1978 | |
29. Glycidyl Ethers | October 12, 1978 | |
30. Epichlorohydrin | October 12, 1978 |
Copies of this and other NIOSH documents are available from:
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