Testing of a mobile heating facility to sanitize N-95 respirators against an enveloped respiratory virus

ABSTRACT

In the spring of 2020, the Alaska Native Tribal Health Consortium (ANTHC) designed and built a sanitizing treatment system to address shortages of filtering facepiece respirators (FFRs). The design criteria included sanitizing large numbers of FFRs, repeatedly achieving FFR fit test requirements, and deactivating enveloped respiratory viruses, such as SARS-CoV-2. The outcome was the Mobile Sanitizing Trailer (MST), a 20 by 8-foot modified trailer designed to process up to 1,000 FFRs during a standard heat cycle. This paper reports on the MST’s ability to: (1) sustain a target temperature, (2) produce tolerable conditions for FFRs as measured by fit factor and (3) successfully deactivate an infectious model virus. We found that the MST reliably and uniformly produced 75 degrees Celsius in the treatment chamber for the prescribed periods. Quantitative analysis showed that the FFRs achieved acceptable post-treatment fit factor even after 18, 60-minute heat cycles. Finally, the treated FFR materials had at least a log 3.0 reduction in viral RNA and no viable virus after 30, 60 or 90 minutes of heat treatment. As a sanitizing treatment during supply shortages, we found the MST a viable option for deactivation of virus and extending the usable life of FFRs. 

KEYWORDS:

• SARS-CoV-2
• filtering facepiece respirator
• reuse
• virus inactivation
• temperature

Acknowledgments

We would like to acknowledge the ANTHC staff that contributed to the design, construction and testing of the MST. Bailey Gamble, Martin Wortman, Mike Findley, George Wallin, Marchquis Pulliam, Noel Mapili, James Anderson, Dave Reed, Joy Britt, Bailey Richards, Chris Fish, Jason Rutman, Gunnar Hodgson, Kolt Garvey, Amanda Setiawan, Luke George, Martin Wortman, David Beveridge, ShawnTakak, Daniel Andrews, Sonny Vinberg, Brian Berube, Andrew Lean, Vannessa Nunnery, and Ida Norton.Thank you for making this project possible! The UAA Laboratory team extends special thanks to Vera Soloview and Dr. Jason Burkhead (UAA).

Availability of Data and Material

Data was generated at the Alaska Native Tribal Health Consortium, Division of Environmental Health and Engineering, and at the University Alaska Anchorage, Bortz Laboratory. The findings are available from the corresponding author on request.

Consent to participate

A recommendation for Dr. Ella Lovejoy to participate in this paper was provided by the Tanana Chiefs Conference, Research and Study Subcommittee on 19 May 2021.

Consent for publication

This manuscript was reviewed and approved for publication by the Alaska Native Tribal Health Consortium, Research Review Committee at their 4 May 2021 meeting.

Ethics approval

This manuscript was reviewed and approved by the Alaska Native Tribal Health Consortium, Research Review Committee at their 4 May 2021 meeting.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

Funding for this project was provided in part by ANTHC and the University of Alaska Anchorage College of Arts & Sciences. Funding for the construction of COVID-19 and virological analysis tools was provided by: the NIAID Centres of Excellence in Influenza Research and Surveillance (CEIRS) award (CRIP: Contract HHSN272201400008C, to E.B.), a Bioinformatics Service award (Pathogenomics, to E.B.) and Graduate Student Fellowship (to R.D.) by the Alaska INBRE programme, and an Institutional Development Award (IDeA) from the National Institute of General Medical Sciences of the National Institutes of Health under grant number 2P20GM103395.