Reprocessing of N95 – safe?


The shortage of N95 masks is driving the efforts to find ways to reprocess (sometimes referred to as decontaminate, sterilize, sanitize or disinfect) these filtering facepiece respirators (FFR). We continue to receive emails expressing concerns from health providers worried that ineffective reprocessing will leave them exposed to contamination or degraded respirators. This is an issue that is evolving, there is ongoing research, and we provide here an update.

Reprocessing is a crisis management tool. Before contemplating reprocessing, all recognized procedures to conserve supplies should be exhausted. The US Centers for Disease Prevention and Control (CDC) provides guidelines for extended use and limited reuse of N95. The guidelines recommend a combination of approaches to conserve supplies while safeguarding health care workers in such circumstances. Extended use refers to the practice of wearing the same N95 respirator for repeated close contact encounters with several patients, without removing the respirator between patient encounters. Reuse refers to the practice of using the same N95 respirator for multiple encounters with patients but removing it (‘doffing’) after each encounter. Both extended use and reuse have been widely used as an option for conserving respirators during previous respiratory pathogen outbreaks and pandemics.

If standard conservation methods are insufficient, reprocessing may become an option. 3M, a major producer of the N95 respirator, states that based on currently available data, 3M does not recommend or support attempts to sanitize, disinfect, or sterilize 3M FFRs. 3M is a private corporation and legally accountable only to its shareholders.

According to the CDC, FFRs are not approved for routine decontamination and reuse as standard of care. However, FFR decontamination and reuse may need to be considered as a crisis capacity strategy to ensure continued availability during the pandemic. Decontamination and subsequent reuse of FFRs should only be practiced as a crisis capacity strategy. Research is ongoing regarding three methods discussed by CDC in the document. To date, no current data exists supporting the effectiveness of these decontamination methods.

One Ontario hospital executive shares that Ontario Health sent guidance documents related to PPE use/conservation and instructed hospitals a few days ago to conserve PPE. Hospitals are expecting to hear more details from Ontario Health related to reprocessing and alternative / repurposing strategies for PPE. In anticipation of these guidelines, hospitals are developing internal processes for sterilization and collection of used PPE (such as N95 masks and face shields). The intention is to follow Ontario Health guidance to ensure the technology, process and standards that are put in place are based on the best available science and expert advice.

A backgrounder with more details about CDC’s approach to extended use, reuse, as well as decontamination and reuse of FFR, can be found here.

The Ontario Command Table informed on April 6 that it will engage targeted actions to ensure Ontario’s patients and workers have the critical supplies and equipment they need by focusing implementation efforts in four areas:

  • Distribution of PPE to the settings and sectors that need it most;
  • Identification of approaches to conserve PPE, working with providers on how best to implement these in workplaces;
  • Harnessing expertise and capacity in other Ontario industries towards the production of clinical supplies and equipment, working with the Ministry of Economic Development, Job Creation and Trade; and
  • Reprocessing of PPE in alignment with forthcoming guidance from the Public Health Agency of Canada.

Researchers from a number of universities scoured the scientific literature to create, a web portal that medical professionals can access for trustworthy information on how to decontaminate used N95 masks.

RNAO wants to stress – again and again – that while masks are very important, you MUST focus on hand hygiene and practice. Please ensure that you:

  • Put your mask on when you arrive and don't take it off.
  • Don't keep fiddling with your mask as every time you touch it you could contaminate yourself.
  • Use a face shield to cover the mask so people don't touch it.

Clean your hands before you come anywhere near your face.