Exposure to fluoride in the chemical industry.

Industries that use fluoride-containing materials are usually aware of their toxicity and adopt adequate medical measures. It has been found that workers in factories who have not been considered as subjected to fluorine hazard and therefore have not been controlled had significantly elevated urinary fluoride levels. Most workers in a medically controlled fertilizer plant had normal urinary levels. Maintenance workers were found to have higher values, up to 12 mg/liter.