Q&A: EUAs for N95 Respirator Decontamination

May 19, 2020

The Food and Drug Administration (FDA) has issued emergency use authorizations (EUAs) for select sterilization systems that will allow N95 or N95-equivalent respirators to be decontaminated and reused.

The following questions from attendees of AAMI’s May 4 webinar, “Emergency Use Authorizations (EUAs) for the Decontamination of N95 Respirators,” and answered by representatives from Advanced Sterilization Products (ASP), Battelle, Sterilucent, STERIS, and 3M.

Q: Are there recommendations for further aeration of N95 masks decontaminated with hydrogen peroxide after delivery?

A: We provide very specific recommendations to users in terms of aeration after decontamination with our STERRAD system. Following those recommendations, we consistently see residual hydrogen peroxide readings of one part per million (ppm). We have confidence that the users and those that are exposed to the vapor will be in a range that is consistent with OSHA (Occupational Safety and Health Administration) and NIOSH (National Institute for Occupational Safety and Health) limits.

—Jeremy Yarwood, vice president of research and development at ASP

A: In order to remove personal protective equipment (PPE) from our decontamination chambers, we must have residual hydrogen peroxide readings of less than one ppm. Certain parts—like foam and the nose pieces on masks—can hold on to the peroxide a little longer than others, so we use measurements from those specific areas on the PPE. By completing these extra checks and others, we found the equipment we return to our customers has readings of less than 1/10 ppm.

—Will Richter, principal research scientist, Battelle

A: We also complete rigorous testing for residuals on our decontaminated equipment. Our aeration times are based on “worst case conditions.” Our target, like everybody else, is below one ppm residual hydrogen peroxide.

—Peter Kalkbrenner, director of engineering at Sterilucent

A: I would agree. We complete extensive testing on residuals and aim for levels well below those that are acceptable. We confidently tell our customers that after our non-lumen decontamination cycle within the V-PRO sterilizers, that no further aeration is required.

—Bill Brodbeck, senior director of regulatory affairs at STERIS


Q: Why are microwave ovens not recommended for decontamination of N95 masks?

A: Based on available literature, microwave oven heating is not compatible with the adhesives and metal parts commonly found in N95 respirators. Microwave energy can heat the metal components, which causes melting of the surrounding materials, which could create pinholes in the filtration materials and distort the shape so it cannot seal to the user’s face. Microwave energy can also melt the adhesive holding the foam and nose pieces in place which could compromise the fit of the respirator.

—Jessica Hauge, application engineering specialist in the personal safety division at 3M

Q: Can EUAs can be extrapolated to other types of masks, like KN95 masks, valve respirators, and duckbill masks?

A: Several large healthcare systems across the country have sent us their KN95 masks for performance testing. We have found some that perform as labeled. NIOSH has published a list of approved N95 particulate filtering facepiece respirators; I would encourage any healthcare system that is thinking of buying KN95 masks or others to make sure the model is on that list.

—Will Richter

A: 3M is publishing lists of our respirator models that are compatible with hydrogen peroxide decontamination methods. Customers should refer to our technical bulletin on the topic for a list of models that are compatible.

—Jessica Hauge

Q: Do you have any tips or resources for those considering going through the EUA process?

A: Early and frequent engagement with the FDA is critical. I would also recommend looking at approved EUAs for an idea of what the processes can look like. Expect a lot of back and forth, as both sides are navigating uncharted territory here.

—Jeremy Yarwood

A: We used an outside consultant to help us with the regulatory process. However, a good place to start is with the FDA’s published guidance documents. Most have contact information in them as well.

—Peter Kalkbrenner

A: I agree that early and frequent communication with the FDA is key. The EUA process during this time is as new to them as it is to us, but they have been fantastic in terms of their communication. The staff have been working around the clock trying to get some of these EUAs through.

—Bill Brodbeck

A: I have to agree. When FDA staff are reaching out to us on a Sunday at 11:00PM to go through more data, you know they are working 24/7 on your EUA. We know it’s an important issue, and they know it’s an important issue.

—Peter Kalkbrenner