TABLE.

Summary of Literature Using Ultraviolet Germicidal Irradiation for Filtering Face Respirators Decontamination

First Author	Year	Dose	Time	Dose	Repeated	Total Accumulated Dose	Distance	Bulb Specs	Effectiveness	Room Conditions	Fit/Degradation
Tseng10	2007		5–255 sec	2.51–6.50 mJ/cm2	1×	2.51–6.50 mJ/cm2	30.5cm	4 × 8 W	Kills 99%, decreased effectiveness at higher humidity	21–28°C, 55% & 85% RH
Viscusi29	2009	0.18–0.20 mW/cm2	15 min/side	324–360 mJ/cm2	3×	0.97–1.08 J/cm2		40W		21°C, 50% RH	No observable physical changes, filtration performance not affected, no noticeable changes in airflow resistance
Bergman36	2010	1.8 mW/cm2	15 min	1.62 J/cm2	3×	4.86 J/cm2	25 cm	40 W		21°C, 50% RH	No observable physical changes, no significant change in penetration
Heimbuch33	2011	1.6–2.2 mW/cm2	15 min	1.44–1.98 J/cm2	1×	1.44–1.98 J/cm2	25 cm	80 W	>4 log reduction		Effective decontamination against droplet and aerosolized influenza challenge, no change to fit after decontamination
Bergman35	2011	1.6–2.0 mW/cm2	15 min	1.44–1.98 J/cm2	3×	4.32–5.94 J/cm2		40 W	>4 log reduction	21°C, 50% RH	Fit not significantly affected after 4 fit tests, no degradation
Viscusi34	2011	1.6–2.0 mW/cm2	15 min/side	2.88–3.96 J/cm2	1×	2.88–3.96 J/cm2		40 W		21°C, 50% RH	No changes in fit, odor detection, comfort, or donning difficulty with UVGI- masks were redonned 5×
Lore37	2012	1.6–2.2 mW/cm2	15 min	1.44–1.98 J/cm2	3×	4.32–5.94 J/cm2	25 cm	2 × 15 W	>4 log reduction		Decontamination methods did not significantly degrade filter performance at 300 nm particle size
Lindsley38	2015		n/a	120–950 J/cm2	1×	120–950 J/cm2	6.2 cm	2 × 15 W		27°C, 25% RH	No significance change in flow resistance, decreased penetration strength and strap breaking strength at very high exposure
Mills11	2018		60–70 sec	1.1 J/cm2	1×	1.1 J/cm2	1 m	8 × 0.39 W/cm2	>3 mean log reduction, straps less effectively decontaminated	21°C, 50% RH	Masks oversaturated with virus in physiologically relevant solvents sebum and mucin, ultraviolet germicidal irradiation levels fully decontaminated masks, statistically significant reduction in virus viability
Heimbuch12	2019	16–18 mW/cm2	60–70 sec	1.0–1.2 J/cm2	20×	20 J/cm2	1 m	8 × 0.39 W/cm2	>3 mean log reduction, straps less effectively decontaminated, tested on SARS-CoV-1	22.5°C	No meaningfully significant effect on fit, air flow resistance, or particle penetration for 15 models tested, some models had significant effects due to donning/doffing cycles
Card42	2020	0.1 mW/cm2	20 min/side	240 mJ/cm2			60.6 cm	30 W
Lowe9	2020	0.2 mW/cm2	5–6 min	300 mJ/cm2			10 ft	16x

Abbreviations: J, Joules; mJ, milliJoules; mW, milliwatts; RH, relative humidity; W, watts.