OSHA's Approach to Risk Assessment for Setting a Revised Occupational Exposure Standard for 1,3-Butadiene

• Published in: Environmental health perspectives 1990-06, Vol.86, p.155-158
• Main Authors: Grossman, Elizabeth A., Martonik, John
• Format: Article
• Language: English
• Subjects: 560300 - Chemicals Metabolism & Toxicology; Air Pollutants, Occupational - adverse effects; AIR POLLUTION; ANIMALS; BIOASSAY; BUTADIENE; Butadienes - adverse effects; CARCINOGENESIS; Carcinogens; Chemical hazards; DIENES; Dosage; Environmental Exposure; Female; Health care administration; Humans; HYDROCARBONS; Inhalation; Male; MAMMALS; MAXIMUM PERMISSIBLE EXPOSURE; MICE; Mouse mammary tumor virus; NATIONAL ORGANIZATIONS; Neoplasms - chemically induced; Neoplasms, Experimental - chemically induced; Occupational Diseases - chemically induced; OCCUPATIONAL EXPOSURE; Occupational health and safety; ORGANIC COMPOUNDS; PATHOGENESIS; POLLUTION; POLYENES; RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT; RATS; Risk analysis; RISK ASSESSMENT; Risk Factors; RODENTS; SAFETY STANDARDS; Toxins; Tumors; United States; United States Occupational Safety and Health Administration; US DOL; US ORGANIZATIONS; US OSHA; VERTEBRATES
• ISSN: 0091-6765; 1552-9924
• DOI: 10.1289/ehp.9086155

In its 1980 benzene decision [Industrial Union Department, ALF-CIO v. American Petroleum Institute, 448 U.S. 607 (1980)], the Supreme Court ruled that "before he can promulgate any permanent health or safety standard, the Secretary [of Labor] is required to make a threshold finding that a place of employment is unsafe-in the sense that significant risks are present and can be lessened by a change in practices" (448 U.S. at 642). The Occupational Safety and Health Administration (OSHA) has interpreted this to mean that whenever possible, it must quantify the risk associated with occupational exposure to a toxic substance at the current permissible exposure limit (PEL). If OSHA determines that there is significant risk to workers' health at its current standard, then it must quantify the risk associated with a variety of alternative standards to determine at what level, if any, occupational exposure to a substance no longer poses a significant risk. For rulemaking on occupational exposure to 1,3-butadiene, there are two studies that are suitable for quantitative risk assessment. One is a mouse inhalation bioassay conducted by the National Toxicology Program (NTP), and the other is a rat inhalation bioassay conducted by Hazelton Laboratories Europe. Of the four risk assessments that have been submitted to OSHA, all four have used the mouse and/or rat data with a variety of models to quantify the risk associated with occupational exposure to 1,3-butadiene. In addition, OSHA has performed its own risk assessment using the female mouse and female rat data and the one-hit and multistage models. While these risk assessments differ in the risks predicted at low doses, they all support OSHA's preliminary determination that there is significant risk of cancer from occupational exposure to 1,3-butadiene at the current OSHA PEL of 1000 ppm. OSHA plans to publish a proposal to revise the current 1,3-butadiene standard. In addition, OSHA will publish a request for public comment on the proposal. OSHA's final standard will be based on its evaluation of the public record and will be guided by significant risk determination.