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Homeland ~ Security 

Science and Technology 

COVID-19 Response: 

Decontamination of N95 Respirators 

with a Multicooker 

EXTENDING USE OF CRITICAL PERSONAL 

PROTECTIVE EQUIPMENT 

Reducing person-to-person spread of SARS-CoV-2 virus is a 

key way to reduce the impact of COVID-19 in the absence of 

an effective treatment. Transmission is believed to occur 

primarily through respiratory droplets produced by talking, 

coughing, and sneezing, though contact with contaminated 

surfaces and objects may also contribute to spread. 

Respiratory protection, including N95 filtering facepiece 

respirators (FFRs), is an effective means of reducing 

exposure, but are in limited supply because of demand. The 

Department of Homeland Security (DHS) Science and 

Technology Directorate (S&T) is executing high-impact 

projects to help answer critical questions about the SARSCoV-2 virus and to support the national response, including the 

assessment of methods for FFR decontamination for reuse. 

ANSWERING CRITICAL QUESTIONS 

S&T has evaluated common household (low technology) 

devices to test at-home treatments with moist heat, one of 

three methods recommended by the U.S. Centers for Disease 

Control and Prevention (CDC)1, as an effective means to 

decontaminate FFRs. 

CURRENT DATA 

S&T identified programmable multicookers with a sous vide 

function, or equivalent setting, as a suitable means to treat 

FFRs with moist heat. Moist heat treatment is achieved by 

placing the FFR(s) in a paper bag and then treating them with 

steam at 149°F (65°C) for 30 minutes, consistent with 

guidance given by the CDC.1 S&T has verified that these 

conditions inactivate SARS-CoV-2 below detectable limits for 

the 3M 1860, 3M 8210, 3M 8511, and Northern Safety 7210 

FFRs. These results were confirmed when SARS-CoV-2 was 

present in culture media, simulated saliva, and simulated lung 

fluid (Table 1). In addition, S&T has confirmed that virus is 

inactivated when up to three masks are nested in the same 

paper bag for treatment. Furthermore, all four of these mask 

models still meet performance specifications after five 

treatments at these conditions (Table 2). Manufacturer 

guidance should be consulted for other models. Note: 3M has 

shown that moist heat treatment can be done up to 10 times 

for the 1860, 8210, 1804, and 1870+ while S&T has confirmed 

this for the 3M 8511 and NS 7210.2 

Table 1. SARS-CoV-2 inactivation results when masks are placed in a paper 

bag and treated at 149°F (65°C) for 30 minutes with steam. 

Inactivation below Detection for Virus in: 

Mask Media Simulated Saliva Simulated Lung Fluid 

3M 1860 Yes Yes Yes 

3M 8210 Yes Yes Yes 

3M 8511 Yes Yes Yes 

NS 7210 Yes Yes Yes 

Table 2. FFR Performance after five decontamination cycles. 

Mask 

Acceptable Performance after Five 

Decontamination Cycles for: 

Filtration 

Efficiency 

Breathing 

Resistance 

Visual 

Inspection 

3M 1860 Yes Yes Yes 

3M 8210 Yes Yes Yes 

3M 8511 Yes Yes Yes 

NS 7210 Yes Yes Yes 

IMPACT 

These results demonstrate that it is feasible for multicookers 

with a sous vide function, or similar capability, to apply moist 

heat to FFRs in a manner that inactivates SARS-CoV-2 virus 

while maintaining performance. When emergency conditions 

exist, new FFRs cannot be obtained, and access to an FDAapproved decontamination facility is not available, this method 

may be considered by persons who have a need to reuse their 

FFR to reduce potential exposures. 

DISCLAIMER 

Individuals assume all responsibility and risk for the use of these instructions for the 

best practices to decontaminate previously worn FFRs DHS does not assume any 

liability for the instructions for best practices contained herein nor do such instructions 

for best practices create any warranty. Reliance on such instructions for best practices 

is solely at your own risk. Further, it is important to note that there are multiple steps 

and variables which may create risk depending upon how the user implements the 

instructions for best practices. 

1 https://www.cdc.gov/coronavirus/2019-ncov/hcp/ppe-strategy/decontaminationreuse-respirators.html 

2 https://multimedia.3m.com/mws/media/1824869O/decontamination-methods-for-3mfiltering-facepiece-respirators-technical-bulletin.pdf 

Contact Us: SandT.Innovation@hq.dhs.gov scitech.dhs.gov dhsscitech 

20 20 -01