Results of chemical ana lysis, animal experiments, and human studies are reviewed, criticized, and found not to support claims of an association between workers exposed to environmental tobacco smoke JETS) and occupational coronary heart disease. This review also recommends refinement of the use of dose surrogates, as presently practiced by the Occupational Safety and Health Administration (OSHA),for regulating indoor emissions from combustion engines, coal furnaces, tobacco leaf processing, rayon viscose manufacturing, and rubber curing. The work standards OSHA uses for regulation of these complex mixtures could also be used in evaluating ETS and relate to the following constituents of ETS: nicotine, carbon monoxide benzo[a]pyrene, and carbon disulfide. The data indicate that the levels of ]these substances potentially arising from ETS are many orders of magnitude below their respective PELs. Thus, based on the standards for exposure surrogates for other complex mixtures, the potential worker exposure from ETS does not require further regulation by OSHA, based on cardiovascular disease.