N95 respirator approval, fit testing and efficiency: New fact sheets from NIOSH

First published by Safety+Health an NSC publication

N 95 masks

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.


McCraren Compliance offers many opportunities in safety training to help circumvent accidents. Please take a moment to visit our calendar of classes to see what we can do to help your safety measures from training to consulting.

‘Extremely hazardous’: Alert warns against using ethylene oxide to sterilize masks, respirators

masks1.jpg

Photo: nanthm/iStockphoto

Tumwater, WA — Ethylene oxide should not be used to sterilize filtering facepiece respirators for reuse because “this extremely hazardous toxic chemical poses a severe risk to human health,” the Washington State Department of Labor & Industries warns in a new alert.

Citing the Environmental Protection Agency and the Centers for Disease Control and Prevention, Washington L&I cautions health care employers and other who sterilize respirators for reuse that ethylene oxide is a carcinogen that “has been linked to neurologic dysfunction and may cause other harmful effects” to the eyes, lungs, brain and nervous system. Further, prolonged exposure could lead to increased risk of reproductive issues and some cancers.

Washington L&I notes that ethylene oxide sterilization systems have not been approved by federal OSHA for personal protective equipment, and evidence suggests using one could result in off-gassing of ethylene oxide in the wearer’s breathing zone.

Although hospitals and clinics are required to use their ethylene oxide sterilizer systems for their intended and manufacturer-approved purposes, they “must NOT be used to sterilize masks, respirators, PPE or items worn by humans,” the alert states.

A shortage of N95 and other filtering facepiece respirators during the COVID-19 pandemic has led some health care facilities to sterilize PPE so it can be reused. In April, the National Institutes of Health recommended three effective methods for sanitizing N95 respirators for limited reuse: vaporized hydrogen peroxide, 70° C dry heat and ultraviolet light.

PPE users should refer to the CDC guidance on optimizing N95 respirator supplies and the Food and Drug Administration’s emergency use authorizations regarding PPE for COVID-19, the alert adds.