TABLE 1.

N95 decontamination methods

Method	Equipment	Tested against SARS-CoV-2	Tested against other biologicals	Pros	Cons	Approved by (HC/FDA)	Key refs
Heat	Oven +/- humidity control	Yes (not directly on N95)	SARS-CoV-1, H1N1/H1N5 Influenza	Simple and available technology; no chemicals	Risk of mask deformation for fit	No	[18, 23– 25]
Autoclave	Standard autoclave	Yes	Bacillus subtilis spores	Available technology; effective in B. subtilis spores	No direct evidence SARS- CoV-2; risk of mask deformation for fit	No	[26, 27]
HPV	STERIS, Battelle (Bioquell)	Yes	Geobacillus stearothermophilus spores, numerous bacteriophages and surrogate respiratory viruses	Low temperature; Breaks down into non- toxic by products	Limited availability, only mask strap breakdown up to 20–30 cycles	Yes	[21, 31, 48, 49]
HPGP	ASP STERRAD	Surrogates, no published data on SARS-CoV-2	Geobacillus stearothermophilus spores	Low temperature; breaks down into non- toxic by products	Limited availability, limited to 3 decontamination cycles for mask integrity	Yes	[29, 36, 50]
iHP	SteraMist binary ionization	Yes	No published data	Low temperature	Limited availability, less testing overall on PPE integrity	No	[17]
EtO	Specialized	No	No	No impact on the filter function and mask appearance	A Known human carcinogen	No	[24, 29]
UV	Specialized lights	No	MS2 bacteriophage; H1N1 influenza	Simple and available technology; no chemicals	May not penetrate inner layers of masks; possibly due to shadowing	No	[51, 52]

EtO = ethylene oxide; HPGP = hydrogen peroxide gas vapour; HPV = hydrogen peroxide vapour; iHP = ionized hydrogen peroxide; SARS-CoV = severe acute respiratory syndrome-associated coronavirus; SARS-CoV-2 = severe acute respiratory syndrome-associated coronavirus 2; UV = ultraviolet light. A STERRAD system uses low-temperature gas plasma combined with HPV