⚠ Status note: this was COVID-era crisis guidance, and OSHA has archived it — it no longer represents OSHA policy. It's kept here as history of what was accepted during the shortage, not as something to rely on today.
When healthcare facilities ran short of N95s during COVID-19, many turned to decontaminating and reusing filtering facepiece respirators (FFRs). OSHA's April 24, 2020 enforcement memo set out which methods it considered acceptable and what employers had to do to qualify for enforcement discretion under the Respiratory Protection standard (29 CFR 1910.134, 1910.134(d)(1)(ii)). It applied to healthcare and emergency response workplaces with SARS-CoV-2 exposure.
The most promising decontamination methods were vaporous hydrogen peroxide, ultraviolet germicidal irradiation, and moist heat (water heated in an oven). If those were unavailable, microwave-generated steam or liquid hydrogen peroxide were acceptable alternatives. OSHA specifically listed methods not recommended without objective data: autoclaving, dry heat, isopropyl alcohol, soap, dry microwave irradiation, chlorine bleach, disinfectant wipes, and ethylene oxide.
Even with an approved method, employers had obligations: implement engineering controls and administrative measures to reduce respirator need, make good-faith efforts to obtain alternative FFRs or elastomeric respirators, ensure user seal checks before each use, visually inspect respirators for compromised integrity, train employees on decontaminated-respirator precautions and proper donning and doffing, and avoid using decontaminated FFRs during aerosol-generating procedures without manufacturer guidance. OSHA exercised case-by-case enforcement discretion only when employers demonstrated all of these efforts plus supply monitoring, CDC prioritization compliance, and surgical masks with eye protection as interim measures.