When properly fitted these NIOSH approved particulate filters with bayonet style attachment protect against a wide range of hazardous environments. Whether it's petrochemical, laboratory, pharmaceutical or chemical manufacturing these filters are a must have to keep you safe. Protects against concentrations of chlorine, hydrogen chloride, sulfur dioxide, hydrogen sulfide, and hydrogen fluoride up to 10x the permissible exposure limits (PEL) with half face pieces, and up to 50x the PEL with full face pieces. Please read and understand all Manufacturer guidelines before attempting to use this product and always exercise the strictest caution when in hazardous environments.