Use in a variety of applications, including petrochemical and chemical processing, utilities, pharmaceuticals, mining and primary metals. When properly fitted, helps provide respiratory protection from certain organic vapors, chlorine, hydrogen chloride, sulfur dioxide, chlorine dioxide, hydrogen sulfide, ammonia, methylamine, formaldehyde or hydrogen fluoride at concentrations up to 10 times the Permissible Exposure Limit (PEL) with half face pieces or 50 times PEL with full face pieces. Full face pieces must be quantitatively fit tested to claim assigned protection factor above 10 in negative pressure mode. Not for use in environments that are immediately dangerous to life or health (IDLH). OSHA requires that gas-proof goggles be worn with half face piece respirators when used against formaldehyde.