Technical Bulletin

April, 2020
Revision 5

Decontamination Methods for 3M Filtering Facepiece Respirators

such as N95 Respirators

Background

NOTE: Please revisit this document often for frequent updates.

During this public health emergency of the COVID-19 pandemic outbreak, many healthcare institutions are experiencing
shortages of filtering facepiece respirators such as N95 respirators. The U.S. Center for Disease Control (CDC) has issued
Strategies for Optimizing the Supply of N95 Respirators. In this document the CDC recommends conventional capacity
strategies, contingency capacity strategies (during expected shortages) and crisis strategies (during known shortages).
Contingency and crisis strategies include use of N95s past their shelf life, extended use of N95s, use of other types of
respirators, use of respirators from other countries, and re-use of respirators, ahead of decontamination of respirators.

The CDC discusses reuse and extended use of N95s as a Crisis strategy at Recommended Guidance for Extended Use and
Limited Reuse of N95 Filtering Facepiece Respirators in Healthcare Settings and has published guidelines on
Decontamination and Reuse of Filtering Facepiece Respirators. CDC says research indicates the virus survives for up to 72
hours on a variety of surfaces. Therefore, CDC is recommending a wait and reuse approach before consideration of other
decontamination approaches.

Key excerpt from CDC guidelines: “The healthcare worker will wear one respirator each day and store it in a
breathable paper bag at the end of each shift. The order of FFR use should be repeated with a minimum of five days
between each FFR use. This will result in each worker requiring a minimum of five FFRs, providing that they put on,
take off, care for them, and store them properly each day. Healthcare workers should treat the FFRs as though they
are still contaminated and follow the precautions outlined in our reuse recommendations. If supplies are even more
constrained and five respirators are not available for each worker who needs them, FFR decontamination may be
necessary.”

Evaluating Decontamination Methods for Filtering Facepiece Respirators

Per the CDC guidelines, a number of sterilization companies are assessing decontamination processes for N95 filtering
facepiece respirators (FFRs). The U.S. Food and Drug Administration (FDA) is evaluating granting Emergency Use
Authorizations (EUAs) for such decontamination systems during the COVID-19 outbreak. Issued EUAs for Personal
Protective Equipment with regards to COVID-19 will be available on the FDA website: Personal Protective Equipment EUAs

3M is collaborating with several sterilization companies and institutions that are investigating ways for hospitals to safely
decontaminate 3M’s N95 FFRs in line with the CDC guidance on Decontamination and Reuse of Filtering Facepiece
Respirators. 3M has been studying ways to sterilize, disinfect or decontaminate filtering facepiece respirators for years.
There are at least four key aspects of successful decontamination reprocessing of respirators, and many published studies
do not take all four into consideration. The method must:

• inactivate the target organism, such as the virus that causes COVID-19;
• not damage the respirator’s filtration;
3M Personal Safety Division

• not affect the respirator’s fit;

• and be safe for the person wearing the respirator.

If, as a result of decontaminating a respirator, the filtration is damaged or the respirator does not fit, it will not help reduce
exposure to airborne particles at the level indicated, such as N95, FFP2, etc. In 3M’s work with external manufacturers of
sterilization/decontamination equipment, 3M relies upon the method developer to confirm the germicidal efficacy of the
method and to provide information on potential hazards to the respirator user.1 3M evaluates the effect of the method on
filtration efficiency and integrity of our respiratory protection products.

To that effect, 3M is testing certain 3M N95 FFRs regarding the effect of the decontamination processes on fit and filtration
performance. We are in the process of testing treated 3M respirators from multiple sterilization companies and institutions.
Methods under evaluation include Vaporized Hydrogen Peroxide, UV, and Low Temperature Moist Heat, amongst others, as
reflected in the CDC Guidance. Other methods of decontamination are being discussed in public forums, including liquid
chemical decontamination, ozone, and time-based methods but 3M is not prioritizing investigation of these methods at this
time. Additional information about many decontamination methods can be found in the CDC guidance on Decontamination
and Reuse of Filtering Facepiece Respirators, but again, many published studies have not considered all four key aspects listed
above. 3M remains committed to providing data to the health care community as soon as possible.

Current Findings on Decontamination Methods

Current information supports the following conclusions for all 3M filtering facepiece particulate respirators2:

• 3M does not recommend the use of Ethylene Oxide due to the potential for repeat inhalation exposure to residual
ethylene oxide, a known human airborne respiratory carcinogen.1 Ethylene oxide is an accepted sterilant for many
device types, but given that the respirator is directly in line with a person’s breathing zone, it is not recommended for
respirator decontamination.
• 3M does not recommend the use of Ionizing Radiation due to degradation in filter performance.
• 3M does not recommend the use of Microwave due to melting of the respirator near metal components resulting in
compromise of fit.
• 3M does not, at this time, recommend the use of High Temperatures above 75°C, such as Autoclave or Steam due to
significant filter degradation.

The table below (Table 1) shows the status of ongoing and completed filtration and fit tests by 3M and EUAs issued to
sterilization equipment manufacturers. We do anticipate that additional information will be available as this work is completed
and reviewed with regulatory agencies. For information on efficacy of decontamination, please refer to the sterilization
equipment manufacturers.

Considering the many variables involved in the process, decontamination of FFRs in the US should follow all requirements of
the current EUA issued for each specific decontamination system.

Please revisit this bulletin often for frequent updates.

1. Note that 3M has established the firm exclusion of ethylene oxide decontamination methods for use with 3M FFRs, because ethylene
oxide is an inhalation-route carcinogen, and any potential off-gassed ethylene oxide residuals would be directly inhaled by the wearer.
2. These conclusions apply to all 3M filtering facepiece respirators including those approved in countries and regions other than the United
States.

2
3M Personal Safety Division

Table 1: Effect of decontamination methods on certain 3M N95 Filtering Facepiece Particulate

Respirators (Sheet 1 of 2)

Number of
3M N95 Reprocess
Decontamination Models Cycles Filtration Fit Related U.S. FDA EUA
Method Evaluated a Cycle Tested Efficiencyb Evaluation Issued

Vaporized Hydrogen Peroxide (VHP) Sterilizer Systems for Decontamination c

VHP – Steris 1860, 8210, V-PRO 1 Plus, 10 Pass Pass EUA

V-Pro 1870+ V-PRO maX,
V-PRO maX2, Facility
Non- Lumen Instructions
Cycle
HC Personnel
Instructions

VHP – Steris 1860, 8210 V-PRO 60 10 Pass Pass No

V-PRO 60 V-PRO s2
Non-Lumen
cycle

VHP –ASP, 1860, 8210 100S-Short 2 Pass Pass EUA

STERRAD® NX-Standard,
100NX-Express Facility
Instructions

HC Personnel
Instructions

VHP - 1804, 1860, Sterilucent™ 10 Pass Pass EUA

Sterilucent 8210 HC 80TT -
Flexible Cycle Facility
Instructions

HC Personnel
Instructions

VHP - Stryker 1804, 1860, STERIZONE VP4 2 Under Under EUA

8210, 1870+ N95 Respirator evaluation evaluation
Decontamination Facility
Cycle Instructions

HC Personnel
Instructions

Vaporized Hydrogen Peroxide Environmental Decontamination Systems

VHP – Ecolab, Under Under Under Under No

Bioquell evaluation evaluation evaluation evaluation

VHP- Battelle 1860, 8210, Under 3 cycles: 3 cycles: 3 cycles: Pass EUA
1804 evaluation tested Pass 20 cycles:
20 cycles: 20 cycles: Under Facility
evaluation Instructions
Under Under
evaluation evaluation HC Personnel
Instructions

3
3M Personal Safety Division

Table 1:Effect of decontamination methods on certain 3M N95 Filtering Facepiece Particulate

Respirators (Continued) (Sheet 2 of 2)

Number of
3M N95 Reprocess
Decontamination
Method
Models Cycles Filtration Fit Related U.S. FDA EUA
Evaluated a Cycle Tested Efficiencyb Evaluation Issued

VHP – Steris - 1860, 8210, STERIS 20 Pass Pass No

Victory™, 1000 1804 Atmospheric
ED, ARD, and VHP Process
M100
Biodecontamin
ation Unit

Ultraviolet Light Environmental Decontamination Systems

UV-C (254 nm) 1860, 8210, 1-2 J/cm2 per Under Under No
1804 side evaluation evaluation

Xenex 1860, 8210, Pulsed xenon, 10 Pass Pass No

Lightstrike™ 1804 200 – 280 nm
System for 5 minutes

Moist Heat

Steris - Moist 1860, 8210, In High 10 Pass Pass No

Heat Method 1804, 1870+ Temperature
using Vis-U-All Self-Seal
High- Pouches (1 FFR
Temperature per pouch)
Self-Seal Temperature =
Pouches 65±5°C,
Humidity =
50-80% RH, 30
min

a. The results on the 1860 are applicable to the 1860S.The results on the 1804 are applicable to the 1804S, 1805, 1805S, 9105,
and 9105S.
b. Per NIOSH requirements applicable to N95 respirators.
c. Per manufacturers of VHP equipment, VHP methods are not to be used with items containing cellulose. See the 3M Tech-
nical Bulletin - Cellulose Certification - Filtering Facepiece Respirators for information about which 3M respirators contain
cellulose.

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