Public health regulations on lead (7439921) exposure are reviewed. Several European countries had developed lead regulations. During the second decade of the century, several studies of occupational lead poisoning were reported, principally by the US Department of Labor. The US Public Health Service recommended a maximum lead exposure of 0.15 milligram per cubic meter (mg/m3) that was generally accepted in 1945. In 1957, the American Conference of Governmental Industrial Hygienists increased the threshold limit value to 0.2mg/m3. In 1971, NIOSH recommended an environmental limit of 0.15mg/m3. The environmental value was based on the NIOSH goal of keeping blood lead values from exceeding 80 micrograms lead per 100 grams whole blood. In 1979, the OSHA standard limiting exposures to 0.05mg/m3 (time weighted average) came into effect. The OSHA regulations also require the employer to make available to workers biological monitoring when airborne lead values reach 30 micrograms/m3. Other major laws related to lead regulations in the US include the Clean Air Act; Safe Drinking Water Act; Food, Drug, and Cosmetic Act; Lead Based Paint Poisoning Act; Poison Prevention Packaging Act; and Mine Safety and Health Act. Reduction of lead in fuels and fuel additives is a major component in the US Environmental Protection Agency program to reduce environmental lead, including lead in ambient air and particularly lead in dirt and dust, which is a major source of lead exposure in children.