OSHA statutory mandate and employer coverage
The Occupational Safety and Health Act of 1970 (OSH Act) declares Congress's purpose "to assure so far as possible every working man and woman in the Nation safe and healthful working conditions." The Act created the Occupational Safety and Health Administration (OSHA) within the Department of Labor and authorized the Secretary of Labor to set mandatory occupational safety and health standards applicable to businesses affecting interstate commerce.
Under 29 U.S.C. § 652(5), an "employer" is "a person engaged in a business affecting commerce who has employees, but does not include the United States (not including the United States Postal Service) or any State or political subdivision of a State." Coverage thus extends to most private-sector employers with at least one employee. The Act excludes self-employed persons and workplaces already regulated by other federal agencies under statutes specifically addressing occupational safety and health (for example, the Mine Safety and Health Act or the Atomic Energy Act).
Source: 29 U.S.C. § 651; 29 U.S.C. § 652
General Duty Clause — employer obligation to provide hazard-free workplace
Section 5(a)(1) of the OSH Act, codified at 29 U.S.C. § 654(a)(1), requires each employer to "furnish to each of his employees employment and a place of employment which are free from recognized hazards that are causing or are likely to cause death or serious physical harm to his employees." Known as the General Duty Clause, this provision functions as a catch-all enforcement mechanism when no specific OSHA standard addresses a particular workplace hazard. The clause has four operational elements: (1) the employer failed to keep the workplace free of a hazard, (2) the hazard was recognized (known to the employer or generally known in the industry), (3) the hazard was causing or likely to cause death or serious physical harm, and (4) there was a feasible and useful method to correct the hazard. OSHA applies this clause to hazards such as workplace violence, ergonomic risks, and heat stress where no promulgated standard exists.
Source: 29 U.S.C. § 654