NIOSH approved against mercury vapor or chlorine. Use with 3M™ Half and Full Facepieces 6000 Series and 3M™ Half and Full Facepieces 7000 Series with bayonet style cartridge holders. When properly fitted, helps provide respiratory protection from mercury vapor or chlorine at concentrations up to 10 times the Permissible Exposure Limit (PEL) with half facepieces or 50 times PEL with full facepieces. Full facepieces must be quantitative