the Occupational Safety and Health Administration (OSHA) used an approach similar to that of the U.S. Food and Drug Administration (FDA) by not defining “safe” as the equivalent of risk-free, because many activities considered safe by most people entail some risk of accident or health damage. Workplace activities or exposures are not considered unsafe unless a significant risk of harm exists. In addition, because of the benefits accrued from employment (e.g., income), workers are presumed to be willing to accept higher levels of risk than would someone to whom little or no benefit accrues from accepting risk. Some studies have shown that salary is commensurate with the level of risk inherent in an occupation (Starr 1969; Whipple 1988).
Supreme Court action (Industrial Union Department, AFL-CIO v. American Petroleum Institute et al. 448 U.S. 607 ) was instrumental in defining acceptable occupational risk for OSHA. The court suggests that significant occupational risk be determined by comparing the risk in question with other common occupational risks levels. The court suggested that an occupational lifetime cancer risk of 1 × 10-3 is significant. On the basis of actuarial data from 1984, the average lifetime (i.e., 45 years) risk of work-related death in a private company with 11 or more employees was 2.9 per 1,000. Risks in high-hazard occupations, like mining, range between 7.6 and 18.6 per 1,000, and risks in low-hazard workplaces, like the service industry, range between 0.9 and 1.8 per 1,000 (Cotter 1986; Rodricks et al. 1987). These rates are measured, not estimated risks, and show little variation from year to year.
OSHA as well as the U.S. Environmental Protection Agency (EPA) and the Nuclear Regulatory Commission have used those lifetime risk values as benchmarks to develop occupational acceptable risk levels. In developing radiation protection guidelines, EPA selected 3 × 10-3 because it was comparable to the working lifetime risk of accidental death in the least hazardous occupations (EPA 46 Fed. Reg. 7836 ; Rodricks et al. 1987). The Nuclear Regulatory Commission stated that the average annual mortality rate in “safe industries” does not exceed 1 × 10-4, which translates to a worker 45-year lifetime risk of approximately 4 × 10-3. Like EPA, the commission proposed occupational standards on the basis of the assumption that worker risks due to radiation are acceptable if kept at or below the “safe industry” risk level (Nuclear Regulatory Commission 1986; Rodricks et al. 1987).
For other workplace carcinogens, OSHA has not regulated below 1 × 10-3, largely because of technical feasibility. Residual lifetime occupational risks associated with permissible exposure levels (PELs) revised in the