Guidelines are provided for controlling occupational exposure to hydrogen-fluoride (7664393). Hydrogen-fluoride in both gaseous and aqueous forms is strongly corrosive and causes severe painful burns to the skin, eyes, and mucous membranes. The respiratory tract is a major site of injury. Exposure to hydrogen-fluoride may occur in aluminum (7429-90-5) smelting, welding, fertilizer production, fluorocarbon and fluoride (16984-48-8) production, metal refining, uranium (7440-61-1) enrichment, and the pickling, etching, and polishing of glass and pottery. Where exposure is likely, work practices should be examined and procedures adopted to ensure that employees are not exposed to an extent likely to adversely affect their health. Personal respiratory protective equipment should be provided where engineering controls are not feasible or do not reduce the hydrogen-fluoride concentration to values below the recommended hygienic standard. Protective clothing and eye protection should be provided and used as necessary. The protective equipment should be made of materials resistant to hydrogen-fluoride. Hydrogen-fluoride should be stored in well ventilated areas and shipped in appropriate containers. Emergency procedures are described for handling hydrogen-fluoride spills or leaks and exposure to fire. Information is provided on the first aid procedures and medical treatment required for hydrogen-fluoride injuries to the skin and eyes and in cases of inhalation.