Worker exposures to tanning chemicals were determined at A. F. Gallum and Son Corporation (SIC-3111) in Milwaukee, Wisconsin on July 22 to 24, 1980. The company employed 183 people, 155 of whom were assigned to production. Sampling was conducted for N-nitroso compounds and precursors, airborne particulates, hydrogen-sulfide (7783064), chrome (7440473), organic solvents, and formaldehyde (50000). N-Nitrosodimethylamine (62759) (NDMA), dimethylamine (124403) (DMA), and airborne nitrosating agents were found at all sample sites. Formaldehyde concentrations exceeded OSHA standards. Mutagen screening was negative and solvent samples were below detectable concentrations. The authors recommend discontinuing the use of dimethylamine-sulfate, reducing formaldehyde concentrations by increasing ventilation or substituting another chemical, and providing a ventilated storage area for formaldehyde.