Laboratory tested at "Nelson Laboratories, Salt Lake City, UT 97% to .1 Micron
F2 is our HEPA (High Efficiency Particulate Air) Filter, made up of 2 layers of particulate filters. The F2 is capable of trapping particulates down to .1 microns in size. *This filter does not contain an active carbon element, eliminating the filtration of fumes and odors. This filter has been laboratory tested to be 97% effective. The HEPA particulate filter promotes 40% better breathability than our standard F1 filter. Common uses: High Intensity, No fumes/odors present.