By Jerome E. Spear, CSP, CIH
There have been recommended occupational exposure standards since the late 1930s. Table 1 illustrates the history of occupational exposure standards for asbestos.
| Year | Promulgating Agency | Standard |
| 1938 | U.S. Public Health Services (Dreesen, Dallavalle, Edwards, Miller, & Sayers, 1938) | 5 mppcf |
| 1939 | State of California (Industrial Accident Commission, State of California, 1939) | 5 mppcf |
| 1945 | State of Oregon (Oregon State Board of Health, 1945) | 5 mppcf |
| 1946 | American Conference of Governmental Industrial Hygienists (ACGIH, 1946) | 5 mppcf |
| 1946 | State of Ohio (Ohio Department of Health, 1946) | 5 mppcf |
| 1951 | U.S. Department of Labor (U.S. Department of Labor, 1951) | 5 mppcf |
| 1957 | State of Texas (Texas State Department of Health, 1957) | 5 mppcf |
| 1969 | U.S. Department of Labor (U.S. Department of Labor, 1969) | 12 f/cc 2 mppcf |
| 1971 | Occupational Safety and Health Administration (OSHA, 1971) | 12 f/cc 2 mppcf |
| 1971 | American Conference of Governmental Industrial Hygienists (ACGIH, 1971) | 5 f/cc* |
| 1972 | Occupational Safety and Health Administration (OSHA, 1972) | 5 f/cc 10 f/cc (Ceiling) |
| 1972 | National Institute for Occupational Safety and Health (NIOSH, 1972) | 2 f/cc |
| 1974 | American Conference of Governmental Industrial Hygienists (ACGIH, 1974) | 5 f/cc |
| 1976 | Occupational Safety and Health Administration (OSHA, 1972) | 2 f/cc 10 f/cc (Ceiling) |
| 1976 | National Institute of Occupational Safety and Health (NIOSH, 1976) | 0.1 f/cc |
| 1980 | American Conference of Governmental Industrial Hygienists (ACGIH, 1980) Amosite Chrysotile Crocidolite Other Forms | 0.5 f/cc (A1) 2 f/cc (A1) 0.2 f/cc (A1) 2 f/cc (A1) |
| 1986 | Occupational Safety and Health Administration (OSHA, 1986) | 0.2 f/cc |
| 1994 | Occupational Safety and Health Administration (OSHA, 1994) | 0.1 f/cc 1 f/cc (Excursion) |
| 1998 | American Conference of Governmental Industrial Hygienists (ACGIH, 1998) | 0.1 f/cc (A1) |
The State of California promulgated Safety Orders in 1936 that regulated workplace exposures to dusts, fumes, vapors, and gases (Industrial Accident Commission, State of California, 1939). In addition to its Maximum Permissible Concentration, the Safety Orders included the following minimum requirements:
- Substitution of non-hazardous equipment, material, or process, whenever practical;
- Isolation of hazardous operations;
- Use of local exhaust ventilation;
- Use of general mechanical ventilation in addition to local exhaust ventilation, when necessary;
- Provide personal protective equipment, including respiratory protection, when the removal of harmful dusts at its source is impractical;
- Provide a change room and hygiene facilities; and
- Sanitize respiratory equipment.
The Walsh-Healey Public Contracts Act established minimum safety and health standards for contractors performing work for any agency of the U.S. Government in any amount exceeding $10,000 (U.S. Department of Labor, 1951). These minimum safety and health standards included, but were not limited to, the following:
- Determine the workers’ exposure concentrations of asbestos and other hazardous materials
- Substitute less hazardous materials
- Provide engineering controls including enclosures, isolation, ventilation (dilution and local)
- Provide personal protective equipment such as respirators and impervious protective clothing
- Decontamination facilities
The OSHA Act of 1970 requires that workers be provided with a workplace free from recognized hazards. OSHA promulgated specification standards for some hazardous substances, including asbestos. These substance-specific standards generally include provisions to address the following:
- Initial and periodic exposure monitoring
- Feasible engineering controls
- Respiratory protection
- Protective clothing, change rooms, and hygiene facilities
- Medical surveillance
- Labels and warnings
- Worker training
As part of early asbestos regulations, OSHA proposed using words “cancer” and “danger” in the 1972 warning label; however, industry lobbying efforts prevented these words from appearing on the final label (Egilman, Bird, & Wilson, 2018; Swetonic, Asbestos Information Association/North America Letter to AIA/NA Member Companies, AIA/NA Environmental Control Sub-Committee, and AIA/NA Legal Counsel, 1972; Markowitz & Rosner, 2016).
OSHA has recognized for several years that its PEL for asbestos was not protective against mesothelioma. In its 1971 emergency temporary standard, OSHA states, “it appears that levels of exposure which may be safe with regard to asbestosis are not safe with regard to mesothelioma” (OSHA, 1971).
In its Revised Recommended Asbestos Standard, NIOSH (1976) states, “excessive cancer risks have been demonstrated at all fiber concentrations studied to date. Evaluation of all available human data provides no evidence for a threshold or for a safe level of asbestos exposure” (NIOSH, 1976).
In its Review and Recommendations to Workplace Exposure to Asbestos, NIOSH (1980) states, “all levels of asbestos exposure studied to date have demonstrated asbestos-related disease…there is no level of exposure below which clinical effects do not occur” (NIOSH, 1980).
In OSHA’s preamble to 29 CFR 1926.1101, Occupational Exposure to Asbestos, OSHA states that a significant risk remains at a PEL of 0.1 f/cc (OSHA, 1994).
References
ACGIH. (1946). Maximum Allowable Concentrations of Air Contaminants for 1946. In Annals of the American Conference of Governmental Industrial Hygienisits: Threshold Limit Values – Discussion and Thirty-five Year Index with Recommendations (pp. 343-344). Cincinnati: ACGIH.
ACGIH. (1971). Threshold Limit Values for Chemical Substances and Physical Agents in the Workroom Environment with Intended Changes for 1972. Cincinnati: ACGIH.
ACGIH. (1974). Threshold Limit Values for Chemical Substances in Workroom Air Adopted by ACGIH for 1974. Cincinnati: ACGIH.
ACGIH. (1980). 1980 Threshold Limit Values Adopted at the 42nd Annual Meeting of the American Conference of Governmental Industrial Hygienists. In Annals of the American Conference of Governmenetal Industrial Hygienists: Threshold Limit Values – Discussion and Thirty-five Year Index with Recommendations (p. 459). Cincinnati: ACGIH.
ACGIH. (1998). 1998 Threshold Limit Values for Chemical Substances and Physical Agents. Cincinnati: ACGIH.
Dreesen, W. C., Dallavalle, J. M., Edwards, T. I., Miller, J. W., & Sayers, R. R. (1938). A Study of Asbestosis in the Asbestos Textile Industry. In Public Health Bulletin No. 241 (p. 91). U.S. Public Health Service.
Industrial Accident Commission, State of California. (1939). Dusts, Fumes, Vapors and Gases Safety Orders. Department of Industrial Relations.
NIOSH. (1972). Criteria for a Recommended Standard: Occupational Exposure to Asbestos. Washington, D.C.: NIOSH.
NIOSH. (1976). Revised Recommended Asbestos Standard. Washington, D.C.: NIOSH.
NIOSH. (1980). Workplace Exposure to Asbestos: Review and Recommendations (No. 81-103). Washington, D.C.: U.S. Department of Health and Human Services.
Ohio Department of Health. (1946). Legal Requirements for the Prevention and Control of Industrial Public Health Hazards. Columbus, Ohio.
Oregon State Board of Health. (1945, August 18). Rules and Regulations for the Prevention and Control of Occupational Diseases. Portland, Oregon.
OSHA. (1971). Occupational Safety and Health Standards, National Consensus Standards and Established Federal Standards. In Title 29 – Labor, Part 1910, Paragraph 1910.93, Table G-3, Mineral Dusts, Federal Register, Vol. 36, No. 105 (p. 10506). Washington D.C.
OSHA. (1972). Standard for Exposure to Asbestos Dust, Federal Register, Volume 27, No. 110. Washington D.C.: OSHA.
OSHA. (1986). Asbestos, Tremolite, Anthophyllite, and Actinolite. In 29 CFR 1026.58, Federal Register, Vol. 51, No. 119 (p. 22757). Washington D.C.
OSHA. (1994). Occupational Exposure to Asbestos, Final Rule, 29 CFR 1926.58. In Federal Register, Volume 59, No. 153 (p. 41133).
OSHA. (1994). Preamble to Final Rule, 29 CFR 1926.1101, Occupational Exposure to Asbestos. Federal Register. Washington, DC.
Texas State Department of Health. (1957, December 1). Maximum Permissible Concentrations of Atmospheric Contaminants in Places of Employment. Austin, Texas.
U.S. Department of Labor. (1951, April 24). Safety and Health Standards for Contractors Performing Federal Supply Contracts under the Walsh-Healey Public Contracts Act. 21-22. Washington, DC: U.S. Government Printing Office.
U.S. Department of Labor. (1969). Safety and Health Standards, Volume 34, No. 12. p. 796. Washington, D.C.