The TR 6820 is a combination High Efficiency (HE) particulate filter and approved cartridge for Hydrogen Fluoride (HF). In addition the filter is treated to remove certain nuisance level organic vapors. This filter may be suitable for use in some smelting operations, and preferred due to its light weight as compared to a standard gas/vapor cartridge. This filter may also be suitable for operations where the primary hazard is particulate but nuisance odors are also present, such as in mold remediation, pharmaceutical and costmetics manufacturing, coking, foundries & metal working, food processing, waste handling or composting. 3M recommends the use of the TR 6800FC filter cover to help protect the filter from physcial damage. The TR 6800FC filter cover is also used to hold the TR 6600 prefilter or TR 662 spark arrestor in place. NIOSH approval: HF/HE