Surveys were conducted to assess techniques to control occupational exposure to mercury (7439976) (Hg) at 24 manufacturing facilities. The facilities included five battery manufacturers (SIC-3691), five thermometer manufacturers (SIC-3829), three fluorescent lamp manufacturers (SIC-3641), two electrical switch manufacturers (SIC- 3643), five electrical processors that used Hg, six chemical manufacturers (SIC-2819), and two dental clinics (SIC-2833). An integrated control approach that included engineering and behavioral controls, personal protection, and monitoring programs was used in every facility except the dental clinics. Temperature control was considered the most effective engineering technique. Other controls included the use of Hg pills in fluorescent lamp manufacturing, smooth impermeable materials on work surfaces and floors, and the use of filters in recirculation systems. Hg exposure concentrations were generally controlled to below acceptable concentrations at most of the facilities, the most notable exception being the battery manufacturers where Hg vapor concentrations were above the OSHA limit of 0.10 milligrams per cubic meter. Recommendations include mandatory wearing of respirators when Hg is handled at elevated temperatures, and routine monitoring of ventilation systems.