This testimony concerned the proposed rule of OSHA on occupational exposure to coal-tar-pitch volatiles. NIOSH is recommending against the adoption of the language which would define coal-tar-pitch volatiles as fused polycyclic hydrocarbons which volatilize from the distillation residues of coal. The concern was that this definition of too narrow as evidence of carcinogenicity from lower molecular polycyclic aromatic hydrocarbons has been presented. Concern was also expressed that many workers would lose protection against polycyclic aromatic hydrocarbons (PAHs) if the proposed regulation were to be adopted. Occupations where elevated cancer risks as a result of exposure to PAHs are documented, or suspected, would be removed from regulation under this proposal. Examples of these would include foundry workers, petroleum workers, roofers, machinists, road pavers, aluminum reduction workers, synthetic fuel workers, shale oil workers, charcoal manufacturers, and others. NIOSH also expressed concern that the proposed regulations were at variance with recent scientific findings. NIOSH suggested that a productive approach to the PAH problem would be to better define the carcinogenic, syncarcinogenic, and cocarcinogenic/promoting agents as well as mechanisms and interactions of PAHs.