Testing of a mobile heating facility to sanitize N-95 respirators against an enveloped respiratory virus.
Michael Brubaker, William Fraser, Keith Cook, Ralf Dagdag, Abigail Nelson, John Warren, Timothy Thomas, Elle Lovejoy, Thomas Kosten, Brandon Maniaci, Eric Bortz, Jacob Gray
Author Information
Michael Brubaker: Department of Community Environment and Health, Community Environment & Health, Alaska Native Tribal Health Consortium (ANTHC), Anchorage, AK USA.
William Fraser: Engineering ANTHC Anchorage, AK, USA.
Keith Cook: Statewide Health Facilities, ANTHC, Anchorage, AK, USA.
Ralf Dagdag: Department of Biological Sciences, University of Alaska Anchorage (UAA), Anchorage, AK, USA.
Abigail Nelson: Community Environment and Health, ANTHC, Anchorage, AK, USA.
John Warren: Director, Department of Standards and Innovation, Standards and Innovation ANTHC, Anchorage, AK, USA.
Timothy Thomas: Clinical and Research Services, ANTHC, Anchorage, AK, USA. ORCID
Elle Lovejoy: Dentist, Department of Dental Health Services, Tanana Chiefs Conference, Fairbanks, AK, USA.
Thomas Kosten: Department of Biological Sciences, UAA, Anchorage, AK, USA.
Brandon Maniaci: Department of Biological Sciences, UAA, Anchorage, AK, USA.
Eric Bortz: Department of Biological Sciences, UAA, Anchorage, AK, USA.
Jacob Gray: Director, Internal Medicine, Alaska Native Medical Center, Anchorage, AK, USA.
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.
