N95 mask reuse in a major urban hospital: COVID-19 response process and procedure

The shortage of single-use N95 respirator masks (NRMs) during the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has prompted consideration of NRM recycling to extend limited stocks by healthcare providers and facilities.

To assess potential reuse via autoclaving of NRMs worn daily in a major urban Canadian hospital.

NRM reusability was assessed following collection from volunteer staff after 2-8 h use, sterilization by autoclaving and PortaCount fit testing. A workflow was developed for reprocessing hundreds of NRMs daily.

Used NRMs passed fit testing after autoclaving once, with 86% passing a second reuse/autoclave cycle. A separate cohort of used masks pre-warmed before autoclaving passed fit testing. To recycle 200-1000 NRMs daily, procedures for collection, sterilization and re-distribution were developed to minimize particle aerosolization risk during NRM handling, to reject NRM showing obvious wear, and to promote adoption by staff. NRM recovery ranged from 49% to 80% across 12 collection cycles.

Reuse of NRMs is feasible in major hospitals and other healthcare facilities. In sharp contrast to studies of unused NRMs passing fit testing after 10 autoclave cycles, we show that daily wear substantially reduces NRM fit, limiting reuse to a single cycle, but still increasing NRM stocks by ∼66%. Such reuse requires development of a comprehensive plan that includes communication across staffing levels, from front-line workers to hospital administration, to increase the collection, acceptance of and adherence to sterilization processes for NRM recovery.