Best practice is to use new N95s. Decontamination does not solve the PPE shortage crisis, and is an emergency practice to beconsidered during the COVID-19 pandemic. Efficacy and safety of N95 decontamination has not been fully characterized.

UV-C

COVID N95
DECON &REUSE

Use appropriate UV-C source
2Validate 1.0 J/cm dose with sensor
Expose both sides of N95 mask

CORONAVIRUS INACTIVATION

Peer-reviewed data not available for SARS-CoV-2

N95 INTEGRITY2≥1.0 J/cm of UV-C inactivates* viruses
similar to SARS-CoV-2 on N95 FFRs1,2**,3N95 keeps fit and filter
performance after 10-20 cycles of
1.0–1.2 J/cm2 UV-C 2**≥1.0 J/cm 2 of UV-C yields 2-log
reduction of viable B. subtilis sporeson N95 FFRs 4

Each don/doff can reduce N95 fit;some models fit unacceptably
after 5 don/doff cycles 9

UV-C light may not reach inner N95
layers for all N95 models 5

Some damage to N95 seen at high
UV-C doses (≥120 J/cm 2 ) 6

Elastic straps require additional
chemical disinfection 1

Strap and facepiece damage seen
on some N95 models after UV-C 7**

Shadows can block UV-C rays & canleave parts of N95 contaminated* ≥ 3-log inactivation

KEY CONSIDERATIONS
Ensure accurate UV-C dose on all surfaces of N95
Measure dose at N95 surface with UV-C specific sensor
Return N95s to original users and ensure handlingminimizes cross-contamination
Perform user seal check before each reuse
Be aware that data from tests on specific N95 models
may not apply to other models

IMPLEMENTATIONCONCLUSIONRISKS
UV light is harmful to eyes and skin ; proper training,
engineering controls, and PPE are required before use

If UV-C source is underpowered, decontamination times
may be infeasible
UV-C may not decontaminate N95 straps or eliminate
risk of bacterial co-infection
Cosmetics and sunscreen on N95 may reduce
decontamination efficacy
Non-uniform irradiance can affect dose, andsubsequently, decontamination efficacy

Reference documents from University of Nebraska Medical Center 8
for implementation
Validate each UV-C source and protocol with a UV-C sensor toensure adequate dose for decontamination at the N95 surface
2

If implemented properly using sensors to ensure ≥1.0 J/cm UV-C dose to the N95, this method likely inactivates SARS-CoV-2; however,this has not yet been confirmed directly with SARS-CoV-2. This method may protect against some bacterial co-infection risks but not all.

SUPPORTING RESEARCH[1] Mills et al., 2018; [2] Heimbuch & Harnish, 2019**; [3] Lore et al., 2012; [4] Lin et al., 2018; [5] Fisher and Shaffer, 2010;[6] Lindsley et al., 2015; [7] Personal Safety Division, 3M, 2020**; [8] Lowe et al., 2020; [9] Bergman et al., 2012** = not peer-reviewed
The Content provided by N95DECON is for INFORMATIONAL PURPOSES ONLY and DOES NOT CONSTITUTE THE
PROVIDING OF MEDICAL ADVICE and IS NOT INTENDED TO BE A SUBSTITUTE FOR INDEPENDENT PROFESSIONALMEDICAL JUDGMENT, ADVICE, DIAGNOSIS, OR TREATMENT. Use or reliance on any Content provided by
N95DECON is SOLELY AT YOUR OWN RISK. A link to the full N95DECON disclaimer can be found athttps://www.n95decon.org/disclaimer.

v2.0 (April 23, 2020)www.n95decon.org

Best practice is to use new N95s. Decontamination does not solve the PPE shortage crisis, and is an emergency practice to beconsidered during the COVID-19 pandemic. Efficacy and safety of N95 decontamination has not been fully characterized.

COVID N95
DECON &REUSE

UV-C
RELATED
CONCERNSUNSUITABLE METHODS
Only UV-C light with a peak wavelength of 254 nm has
demonstrated substantial germicidal effects on N95 FFRs.1**
UV-A (320-400 nm) is not germicidal. UV-B (280-320 nm) has lower
germicidal efficiency and has not been validated for N95 FFR
decontamination.2 Only use UV-C light sources with a peakwavelength of 254 nm.
Tecnowatt s.r.l.

Sunlight

Sunlight reaching the Earth’s surface does not contain UV-C light; 3 there is noevidence in the peer-reviewed literature to support sunlight-assisted
decontamination of N95 FFRs.

Consumer UV
Products

Many consumer UV products do not emit UV-C with sufficient irradiance, andhave peak emission in the UV-A range (e.g., nail polish curing lamps,4 tanning
bed lamps,5 etc.), which is ineffective for decontamination. Other consumer
products may additionally have uniformity or shadowing concerns.

< 200 nm UVSources

UV sources emitting < 240 nm light can produce ozone, which is hazardous tohuman health.6** Sufficient ventilation is necessary to reduce ozone
concentration.7

Measuringdose fromlamp power

UV-C irradiance should not be calculated from rated lamp power, as bulbs do nothave 100% efficiency in converting electrical energy to optical power.8 Use a UVC specific sensor to measure irradiance at the N95 surface.

Doses for airor surface
decon

Viral inactivation protocols designed for surfaces or air are insufficient/noteffective for N95 decontamination.9 Use a substantially higher UV-C dose of 1.02J/cm at the N95 surface. 1**BiosafetyCabinets

Many UV-C sources used in research laboratories (e.g., biosafety cabinets) haveunacceptable non-uniformity and low power;10** thorough characterization of theUV-C dose at the N95 surface is required for sufficient decontamination.

SUPPORTING RESEARCH[1] Heimbuch & Harnish, 2019**; [2] Kowalski, 2009; [3] Sagripanti and Lytle, 2005; [4] Dowdy & Sayre, 2013; [5] Spencer & Amonette, 1995
[6] Oxidation Technologies LLC, 2017;** [7] McClurkin et al., 2013; [8] Lawal et al., 2017; [9] Walker & Ko, 2007; [10] Card et al., 2020**** = not peer-reviewed
The Content provided by N95DECON is for INFORMATIONAL PURPOSES ONLY and DOES NOT CONSTITUTE THE
PROVIDING OF MEDICAL ADVICE and IS NOT INTENDED TO BE A SUBSTITUTE FOR INDEPENDENT PROFESSIONALMEDICAL JUDGMENT, ADVICE, DIAGNOSIS, OR TREATMENT. Use or reliance on any Content provided byN95DECON is SOLELY AT YOUR OWN RISK. A link to the full N95DECON disclaimer can be found athttps://www.n95decon.org/disclaimer.

v1.0 (April 23, 2020)www.n95decon.org