Occupational exposure to fluoride is extensively reviewed. Topics include acute effects producing lung and skin injury, chronic effects, industrial sources of fluoride, air concentrations versus urinary concentrations of fluoride, osteosclerosis and the fluoride air standard, osteosclerosis and bone fluoride, osteosclerosis with air fluoride concentrations in excess as well as less than 2.5 milligrams of fluorine per cubic meter with urine levels greater than 9 and less than 5 milligrams of fluorine per liter, respectively, research needs, incidence of arthritis, lung effects and the standard, irritancy, shortness of breath, asthma, upper respiratory infections, chronic respiratory disease, kidney effects and the standard, skin disorders, pregnancy, indices of fluoride intoxication, health effects of fluoride emissions in the surrounding community, Chizzola maculae, and air quality standards for man. Extensive tables give responses in man exposed to airborne fluorides in the work place and responses in neighborhood residents exposed to fluoride emissions. Other tables give estimated total fluoride emissions from major industrial sources in the United States in 1968, presence of osteosclerosis, radiographic changes and years of exposure, and comparison of fluoride effects in man and animals. The evidence is considered to show that the threshold limit value has been effective and justifies the OSHA standard of 2.5 milligrams of fluorine per cubic meter.