Washington — NIOSH has issued a pair of fact sheets on filtering facepiece respirators, detailing how to tell if an N95 is approved by the agency as well as procedures for fit testing and testing filtration efficiency.
With an NIOSH-approved respirator, “you can be confident that it is working as expected” as long as it is properly maintained, is worn and used correctly, fits properly, and is replaced as recommended by the manufacturer.
“NIOSH only approves respirators that pass its strict quality assurance and performance requirements,” the agency says. During its tests, NIOSH uses a “near worst-case penetrating aerosol size (i.e., particles that are best able to make it through a filter).” An N95 respirator must block at least 95% of those particles, which typically measure at 0.3 microns in diameter.
The fact sheet on fit testing and filtration efficiency testing covers the types of fit tests: qualitative and quantitative. It also includes a short checklist to ensure an N95 is protecting the user.