PPE CASE

Personal Protective Equipment Conformity Assessment Studies and Evaluations

Assessment of Filtration Efficiency, Manikin Fit 

Performance, and Strap Performance for Decontaminated 

N95 Filtering Facepiece Respirators

National Institute for Occupational Safety and Health (NIOSH) 

National Personal Protective Technology Laboratory (NPPTL) 

This report summarizes the NIOSH assessments of filtration efficiency, 

manikin fit performance, and strap performance of NIOSH-approved N95 

filtering facepiece respirators (FFRs) that have undergone various 

decontamination techniques. Based on the knowledge gained from these

assessments, this report discusses important considerations when 

selecting techniques of FFR decontamination for occupational use.

Findings from the NIOSH assessments indicate that FFR decontamination 

may have model-specific effects — the FFR manufacturer should be 

consulted before decontaminating any FFR. 

The purpose of this assessment was to determine the effects of the 

decontamination process on the particulate filtration performance, 

manikin fit, and strap integrity of the respirator. It did not assess the 

reduction of the pathogen burden by the decontamination procedure.

Background

Supplies of N95 filtering facepiece respirators (FFRs) can become depleted during wide-spread 

outbreaks of infectious respiratory illnesses. In order to supplement the national inventory of N95 FFRs 

during these times, the Centers for Disease Control and Prevention (CDC) suggested several supply 

optimization strategies (CDC 2020). Within these strategies, FFR reuse, including reuse after 

decontamination, when there are known shortages of N95 respirators may be considered.

Evaluation of a 

convenience sample of 

1,354 N95 FFR units 

across 29 models found 

that 42% of the 

decontamination 

techniques evaluated (8 of 

19) negatively impacted 

fit and/or filtration 

efficiency.

 

 

 

 

 

 

 

 
2

Decontamination is a process to reduce the number of pathogens on used FFRs before reuse. An 

effective FFR decontamination technique should significantly reduce the pathogen burden, but not 

reduce a respirator’s filtration performance or its ability to fit properly. Another consideration is that 

no hazardous chemical residue should be left on the FFR as a result of a decontamination process.

During non-emergencies, FFRs are considered limited-use products and are not approved for 

decontamination and reuse as standard of care. However, when there are known FFR shortages FFR 

decontamination and reuse may need to be implemented as a crisis capacity strategy to ensure 

continued availability after conventional and contingency strategies have been implemented. On 

March 29, 2020, the U.S. Food and Drug Administration (FDA) issued the first Emergency Use 

Authorization (EUA) for a decontamination technique to be considered to offset N95 FFR supply 

shortages. Since then, additional subsequent EUAs and revisions have been issued. The FDA Emergency 

Use Authorizations website should be checked for the most up-to-date information. Furthermore, 

the respirator manufacturer should be consulted about any impact that the decontamination 

technique has on their respirators before considering the use of any technique

How NIOSH Assessed FFRs that have Undergone a 

Decontamination Technique

The goal of the assessments discussed in this report is to provide information that can be used to 

inform decisions regarding implementing N95 FFR decontamination and reuse during national 

emergencies when respirator supplies are diminished. This study is ongoing. The results presented 

within this PPE CASE are from the time period of April 14, 2020 through December 01, 2020.

These assessments used new FFRs that had not been worn or exposed to any pathogenic 

microorganisms. In practice, donning a respirator multiple times can reduce the ability of the respirator 

to fit properly. While these assessments evaluated the performance of respirators that were 

decontaminated up to 30 cycles, CDC recommends limiting the number of donnings to no more than 

five in the absence of guidance from manufacturers or targeted evaluations of fit with repeated 

decontamination cycles. 

NIOSH developed performance test methods to evaluate N95 FFRs following decontamination 

techniques (see Appendix B).

• NIOSH received requests from multiple organizations including hospitals, universities, private 

companies performing sterilization services, and government and private research laboratories 

to assess unused N95 FFRs that had undergone decontamination. Assessment requests 

required the respirator manufacturer name, model number, a detailed description of the 

decontamination technique and number of decontamination cycles applied, and whether the 

technique used was one authorized for emergency use by the FDA. NIOSH determined 

particulate filtration efficiency by using a modified version of the NIOSH Standard Test 

Procedure (STP)-0059. 
3

• Manikin fit was determined using manikin headforms developed to represent the 

anthropometric sizes of US workers1. 

• NIOSH assessed strap integrity (difference in tensile force compared with controls) of the top

and bottom straps by using a tensile tester, a device which measures tensile force by elongating 

(stretching) a test sample at 1 cm/sec until reaching by 200% strain. See Appendix B for more 

detailed procedures.

• FFRs were also visually inspected for signs of component damage or discoloration compared to 

controls (i.e. unused respirators of the same manufacturer and model). 

• The selection of respirators to provide to NIOSH for testing was at the discretion of the 

submitter; however, NIOSH requested 15 decontaminated respirators and five new respirators 

to use as controls for each assessment.

• In total, NIOSH tested 1,354 respirators during this evaluation to support 39 assessments that 

are described in this report. Manufacturer lot-to-lot product variability was not considered in 

these assessments. It is possible that some of the variability in the data was due to lot-to-lot 

product differences. Table 1 summarizes the number of respirators tested by the provided 

decontamination dose as well as the number of decontamination cycles performed. Figure 1 

displays the number of respirators tested by manufacturer and model number. 

1 Bergman, Michael S et al. “Development of an advanced respirator fit-test headform.” Journal of occupational 

and environmental hygiene vol. 11,2 (2014): 117-25. doi:10.1080/15459624.2013.816434
Table 1 – Sample size by decontamination technique, dose described, cycle number, and respirator model

Technique N Doses Tested N Cycles Tested N Models Tested

Aerosolized Peracetic Acid (PAA) 24 76 min x 1.06% PAA 

solution 24

1 cycle 8 3M 1860 (n=8)

3 cycles 8 3M 1860 (n=8)

5 cycles 8 3M 1860 (n=8)

Chlorine Dioxide Gas 88

1000–2000 ppm-hr* 25

5 cycles 5 3M 8000 (n=5)

10 cycles 5 3M 8000 (n=5)

20 cycles 15 3M 8000 (n=15)

2,500 ppm-hr* 4 4 cycles 4 3M 8200 (n=4)

850 ppm-hr* 15 5 cycles 15 3M 8200 (n=15)

720 ppm-hr* 44 1 cycle 14 3M V-Flex 1805 (n=14)

4 cycles 30 3M 1860 (n=15), VWR 89201-508 (n=15)

Commercial Steamer 15 30 seconds at 100°C 15 10 cycles 15 3M 8210 (n=15)

DiKlor-G® Sterilization, Chlorine Dioxide 30 800 ppm-hr* 15 6 cycles 15 3M 8210 (n=15)

Not reported 15 6 cycles 15 3M 1860 (n=15)

Dry Heat (commercial laundry dryer) 90

90 min at 80-85°C 45 3 cycles 45 3M 1860 (n=15), 3M 8511 (n=15), Halyard 62126 (n=15)

70 min at 80-85°C 45 3 cycles 45 3M 1860 (n=15), 3M 8511 (n=15), Halyard 62126 (n=15)

Dry Heat (environmental chamber) 125

60 min at 75°C 30 5 cycles 30 3M 1860 (n=10), 3M 1870+ (n=10), Halyard 46727 (n=10)

45 min at 75°C 95 10 cycles 95 3M 1860 (n=15), 3M 1860S (n=15), 3M 1870+ (n=15),

3M 8210+ (n=20), 3M 9205+ (n=15), 3M V-Flex 1804 (n=15)

Electron Beam Irradiation 10 25 kGy/cycle 10

1 cycle 4 3M 8200 (n=4)

2 cycles 3 3M 8200 (n=3)

3 cycles 3 3M 8200 (n=3)

Gaseous Ozone 5 450 ppm** 5 5 cycles 5 3M 1870 (n=5)

Gravity Steam 21 30 min at 121°C 21 3 cycles 21 3M 1860 (n=7), 3M 1870 (n=7), 3M V-Flex 1905 (n=7)

Methylene Blue 44 10μM spray (~7mL/cycle) + 

100k lux light for 60 mins 44 5 cycles 44 3M 1860 (n=10), 3M 1860S (n=15), 3M 1870+ (n=10),Halyard 46727 (n=9)

Microwave generated plasma 14 45 seconds 14 3 cycles 14 3M 1860 (n=7), 3M 8210 (n=7)
5

Table 1 Continued – Sample size by decontamination technique, dose described, cycle number, and respirator model

Technique N Doses Tested N Cycles Tested N Models Tested

Moist Heat 45

60 min at 100°C & 100%RH 24

1 cycle 8 3M 1860 (n=8)

3 cycles 8 3M 1860 (n=8)

5 cycles 8 3M 1860 (n=8)

15 min at 85°C & 65%RH 21

1 cycle 7 3M 1860 (n=7)

3 cycles 7 3M 1860 (n=7)

5 cycles 7 3M 1860 (n=7)

Plasma Discharge Reactive Oxygen Species 12 500 ppm-min* 12 1 cycle 6 BYD DE2322 (n=3), Prestige Ameritech RP88020 (n=3)

3 cycles 6 BYD DE2322 (n=3), Prestige Ameritech RP88020 (n=3)

Sterrad NX100 HPV/Low Temp Plasma 30 Not reported 30 2 cycles 30 3M 8511 (n=15), Halyard 46727 (n=15)

Stryker STERIZONE VP4 Sterilizer 30 Pre-set cycle (Cycle 1), 41°C 30 5 cycles 30 3M 1860 (n=10), 3M 1870+ (n=10), Halyard 46727 (n=10)

Supercritical Carbon Dioxide 34 60 min at 37°C & 1100 psig 15 10 cycles 15 3M 1860 (n=15)

90 min at 37°C 19 1 cycle 19 3M 1860 (n=6), 3M 1860S (n=7), 3M V-Flex 1804 (n=6)

Ultraviolet Germicidal Irradiation (UVGI) 32

UV-C 254nm 1000 mJ/cm2 12 10 cycles 12 3M 1860 (n=7), 3M 8210 (n=5)

UV-C 254nm 500 mJ/cm2 20

1 cycle 5 3M 1860S (n=5)

3 cycles 5 3M 1860S (n=5)

5 cycles 5 3M 1860S (n=5)

10 cycles 5 3M 8210 (n=4), 3M 8210+ (n=1)

UVGI and Infrared Heat 28 90 min at 175°C 28

3 cycles 15 Halyard 46727 (n=15)

5 cycles 13 Halyard 46727 (n=13)
6

Table 1 Continued – Sample size by decontamination method, dose described, cycle number, and respirator model

N Doses Tested N Cycles Tested N Models Tested

Vapor Phase Hydrogen Peroxide (VPHP) 677

25 min at 45°C with 35% HP 24

10 cycles 8 Makrite 9500-N95S (n=8)

20 cycles 8 Makrite 9500-N95S (n=8)

30 cycles 8 Makrite 9500-N95S (n=8)

3 hours at 7% 125

1 cycle 25 3M 8000 (n=5), 3M 8210 (n=5), 3M 8210V (n=5),

Crosstex GPRN95 (n=5), Moldex 1512 (n=5)

2 cycles 25 3M 8000 (n=5), 3M 8210 (n=5), 3M 8210V (n=5),

Crosstex GPRN95 (n=5), Moldex 1512 (n=5)

3 cycles 25 3M 8000 (n=5), 3M 8210 (n=5), 3M 8210V (n=5),

Crosstex GPRN95 (n=5), Moldex 1512 (n=5)

4 cycles 25 3M 8000 (n=5), 3M 8210 (n=5), 3M 8210V (n=5),

Crosstex GPRN95 (n=5), Moldex 1512 (n=5)

5 cycles 25 3M 8000 (n=5), 3M 8210 (n=5), 3M 8210V (n=5),

Crosstex GPRN95 (n=5), Moldex 1512 (n=5)

Not reported 528

5 cycles 154

3M 1860 (n=7), 3M 1860S (n=6), 3M 8210 (n=7), 3M 8511 (n=15),

3M 9205+ (n=15), V-Flex 1804 (n=7), Gerson 1730 (n=14),

Gerson 1740 (n=14), Moldex 1512 (n=12), Moldex 2200 (n=12), 

Sperian N1105 (n=15), Sperian N1125 (n=15), Sperian One-Fit (n=15)

10 cycles 174

3M 1860 (n=15), 3M 8210 (n=15), 3M 8511 (n=15), 3M 9205+ (n=15),

V-Flex 1804 (n=15), Gerson 1730 (n=15), Gerson 1740 (n=14), 

Moldex 1512 (n=15), Moldex 2200 (n=15), Sperian N1105 (n=15), 

Sperian N1125 (n=15), Sperian One-Fit (n=10)

15 cycles 15 3M 1860 (n=15)

20 cycles 185

3M 1860 (n=15), 3M 1870+ (n=10), 3M 8210 (n=15), 3M 8511 (n=15),

3M 9205+ (n=15), V-Flex 1804 (n=15), Gerson 1730 (n=15),

Gerson 1740 (n=15), Moldex 1512 (n=15), Moldex 2200 (n=15), 

Sperian N1105 (n=15), Sperian N1125 (n=15), Sperian One-Fit (n=10)

*Concentration and time not reported; ** Time not reported
Figure 1 – Respirator Models Tested 

CASE Results 

Detailed results for each decontamination technique by dose, cycle number, and respirator model are 

presented as supplementary tables in the Appendix. Additionally, all detailed assessment reports are 

posted on the NIOSH website. Because not all respirators were tested with each decontamination 

method the results cannot be generalized. However, the results do suggest effects that can be further 

tested.

Table 2 displays the percent of decontaminated respirators that had ≥95% filtration efficiency by 

decontamination technique and the number of decontamination cycles. The majority of 

decontamination techniques and their stated treatment (dose and cycle) did not negatively impact 

filtration efficiency. However, filtration efficiency was impacted negatively for specific 

decontamination techniques and their stated treatment (dose and cycle). Specifically, respirators 

decontaminated using Electron Beam Irradiation, Microwave Generated Plasma, Supercritical Carbon 

Dioxide, and Ultraviolet Germicidal Irradiation (UVGI) used in combination with Infrared Heat showed 

filtration efficiency of <95% following decontamination compared to controls in some or all of the 

respirators tested. The remaining decontamination techniques did not have a substantial impact on 

filtration efficiency, with most or all of the decontaminated respirators having achieved ≥95% filtration 

efficiency across all numbers of cycles tested. 
8

Table 2 – Percent of respirators with ≥95% filtration efficiency by decontamination technique and cycle number

Number of decontamination cycles

All Cycles 1 2 3 4 5 6 10 15 20 30

PAA 100% 100% 100% 100%

n=15, m=1 n=5, m=1 n=5, m=1 n=5, m=1

ClO2 Gas 100% 100% 100% 100% 100%

n=54, m=5 n=10, m=1 n=24, m=3 n=10, m=1 n=10, m=1

Commercial 

Steamer

100% 100%

n=10, m=1 n=10, m=1

DiKlor-G®

Sterilization, ClO2

100% 100%

n=20, m=2 n=20, m=2

Dry Heat

(laundry dryer)

100% 100%

n=60, m=3 n=60, m=3

Dry Heat

(environ. chamber)

100% 100% 100%

n=81, m=7 n=21, m=3 n=60, m=6

Electron Beam 

Irradiation

0% 0% 0% 0%

n=10, m=1 n=4, m=1 n=3, m=1 n=3, m=1

Gaseous Ozone 100% 100%

n=5, m=1 n=5, m=1

Gravity Steam 100% 100%

n=15, m=3 n=15, m=3

Methylene Blue 96% 96%

n=32, m=4 n=32, m=4

Microwave 

Generated Plasma

90% 90%

n=10, m=2 n=10, m=2

Moist Heat 100% 100% 100% 100%

n=21, m=1 n=7, m=1 n=7, m=1 n=7, m=1

Plasma Discharge 

ROS

100% 100% 100%

n=12, m=2 n=6, m=2 n=6, m=2

Sterrad NX100 

HPV/LTP

100% 100%

n=20, m=2 n=20, m=2

Stryker STERIZONE 

VP4 Sterilizer

100% 100%

n=21, m=3 n=21, m=3

Supercritical CO2 0% 0% 0%

n=23, m=3 n=13, m=3 n=10, m=1

UVGI 100% 100% 100% 100% 100%

n=26, m=4 n=5, m=1 n=5, m=1 n=5, m=1 n=11, m=3

UVGI and Infrared 

Heat

50% 100% 0%

n=20, m=1 n=10, m=1 n=10, m=1

VPHP

99% 100% 100% 100% 100% 100% 99% 100% 97% 100%

n=473, m=17 n=17, m=5 n=19, m=5 n=19, m=5 n=19, m=5 n=128, m=16 n=125, 

m=13

n=10, 

m=1

n=131, 

m=14

n=5, 

m=1

Percent for the “All Cycles” column was calculated as an average change weighted by the number of samples in each cycle number. Sample size (n) = number 

of decontaminated respirators tested for each cell. m = number of different models tested.

Acronyms: PAA=Aerosolized Peracetic Acid, ROS=Reactive Oxygen Species, LTP= Low Temp Plasma, UVGI=Ultraviolet Germicidal Irradiation, VPHP=Vapor 

Phase Hydrogen Peroxide
9

Table 3 displays the percent of respirators with manikin fit factors of ≥100 by decontamination 

technique and number of cycles. The percentage of control respirators (no decontamination) with a 

manikin fit factor of ≥100 by decontamination technique is also provided in Table 3 for comparison. 

Comparing the percentage of control respirators with the percentage of respirators across all 

decontamination cycles, clarifies that the manikin fit factor is reduced following some of the 

decontamination techniques. Specifically, Chlorine Dioxide Gas, Gravity Steam, Microwave Generated 

Plasma, Moist Heat, Sterrad NX100 Hydrogen Peroxide Vapor (HPV)/low temp plasma, Supercritical 

CO2, UVGI in combination with infrared heat, and VPHP show a reduction in manikin fit in the 

decontaminated respirators compared to the controls, independent of the number of decontamination 

cycles. A reduction in manikin fit was not observed for the other 8 decontamination techniques, where 

the number of respirator models evaluated ranged from 5 to 44 for each decontamination technique. 

Table 3 does not break out the results by respirator model, thus the passing percentages shown in the 

table may have been impacted by the specific models tested. However, the number of different 

models tested within each cell is indicated within Table 3 to aid in this interpretation.

Figure 2 displays boxplots of the percentage change in strap tensile force between the control and 

decontaminated straps (decontaminated tensile force – control tensile force)/control tensile force) by 

decontamination technique and strap location (top or bottom strap). A value less than 0% indicates 

that there was less tensile force measured in the decontaminated strap than in the control straps. A 

value greater than 0% indicates there was more tensile force measured in the decontaminated strap 

than in the control. The strap integrity results were largely mixed with both positive and negative 

percent changes in tensile force within and between the decontamination techniques. Many of the 

techniques had an interquartile range that included 0%, which indicates no obvious reduction or 

increase in tensile force from decontaminated straps tested to control straps. However, the 

Commercial Steamer and DiKlor-G® Sterilization, Chlorine Dioxide techniques showed substantially 

increased tensile force in the decontaminated respirators versus the controls.
Table 3 – Percentage of respirators with a manikin fit factor of ≥100 by decontamination technique and cycle number

Number of decontamination cycles

Control All Cycles 1 2 3 4 5 6 10 15 20 30

PAA 100% 100% 100% 100% 100%

n=2, m=1 n=9, m=1 n=3, m=1 n=3, m=1 n=3, m=1

ClO2 Gas 93% 83% 100% 50% 100% 100% 80%

n=26, m=4 n=34, m=4 n=4, m=1 n=10, m=2 n=10, m=2 n=5, m=1 n=5, m=1

Commercial 

Steamer

100% 100% 100%

n=2, m=1 n=5, m=1 n=5, m=1

DiKlor-G®

Sterilization, ClO2

100% 100% 100%

n=4, m=2 n=10, m=2 n=10, m=2

Dry Heat

(laundry dryer)

100% 100% 100%

n=12, m=3 n=30, m=3 n=30, m=3

Dry Heat

(environ. chamber)

92% 92% 100% 88%

n=12, m=7 n=44, m=7 n=9, m=3 n=35, m=6

Gravity Steam 100% 67% 67%

n=6, m=3 n=6, m=3 n=6, m=3

Methylene Blue 100% 100% 100%

n=2, m=1 n=12, m=4 n=12, m=4

Microwave 

Generated Plasma

100% 75% 75%

n=4, m=2 n=4, m=2 n=4, m=2

Moist Heat 100% 22% 17% 17% 33%

n=5, m=1 n=24, m=1 n=8, m=1 n=8, m=1 n=8, m=1

Sterrad NX100 

HPV/LTP

100% 60% 60%

n=4, m=2 n=10, m=2 n=10, m=2

Stryker STERIZONE 

VP4 Sterilizer

100% 100% 100%

n=9, m=3 n=9, m=3 n=9, m=3

Supercritical 

Carbon Dioxide

100% 45% 33% 80%

n=8, m=3 n=11, m=3 n=6, m=3 n=5, m=1

UVGI 100% 100% 100%

n=4, m=2 n=6, m=3 n=6, m=3

UVGI and Infrared 

Heat

100% 50% 100% 0%

n=4, m=1 n=8, m=1 n=5, m=1 n=3, m=1

VPHP 94% 88% 60% 100% 100% 100% 94% 90% 100% 86% 0%

n=56, m=12 n=204, m=16 n=8, m=5 n=6, m=5 n=6, m=5 n=6, m=5 n=51, m=16 n=57, m=13 n=5, m=1 n=62, m=14 n=3, m=1

Percent for the “All Cycles” column was calculated as an average change weighted by the number of samples in each cycle number. Sample size (n) = number of decontaminated 

respirators tested for each cell. m = number of different models tested. 

Acronyms: PAA=Aerosolized Peracetic Acid, ROS=Reactive Oxygen Species, LTP= Low Temp Plasma, UVGI=Ultraviolet Germicidal Irradiation, VPHP=Vapor Phase Hydrogen Peroxide

CASE Conclusions

The decontamination techniques and respirator models included in this assessment were not selected 

by NIOSH and were at the sole discretion of the decontamination providers. Therefore, this report 

includes an exploratory analysis of a convenience sample and may not be generalizable to all 

decontamination techniques or N95 FFRs.

The results of the evaluations suggest that some FFR decontamination techniques did not substantially 

impact filtration efficiency, manikin fit factor, or strap integrity while other techniques had a negative 

impact. Specifically, the following decontamination techniques were not shown to reduce filtration 

efficiency or manikin fit (See Appendix B for specific information on FFR models tested, dose, and 

number of cycles):

• PAA

• Chlorine dioxide gas

• Commercial steamer

• DiKlor-G® sterilization

• Dry heat in a commercial laundry dryer or environmental chamber

• Methylene blue plus light

• Stryker STERIZONE VP4 Sterilizer

The data suggest that these techniques practiced with their specified number of cycles and dose may 

not negatively impact FFR performance; however, studies should be developed that control for and 

explore various treatments across numerous models to provide greater confidence in these findings.

Some techniques reduced filtration efficiency to less than 95% in some or all of the tested FFRs:

• Supercritical CO2 (evaluated for 3 models)

• Electron beam irradiation (evaluated for 1 model)

• UVGI in combination with infrared heat (evaluated for 1 model)

Some techniques negatively impacted manikin fit when compared to controls in some or all of 

the tested FFRs:

• FFRs decontaminated using gravity steam (evaluated for 2 models)

• Microwave generated plasma (evaluated for 2 models)

• Moist heat (evaluated for 1 model)

• Sterrad NX100 HPV/low temp plasma (evaluated for 2 models)

• Supercritical CO2 (evaluated for 3 models)

• UVGI in combination with infrared heat (evaluated for 2 models)

• Vapor Phase Hydrogen Peroxide (VPHP) (evaluated for 16 models)

While the filtration efficiency and manikin fit results were stratified by the number of decontamination 

cycles in Tables 2 and 3 of this report, the number of cycles did not systematically influence the results. 

No obvious filtration or manikin fit degradation pattern was observed across the number of 

decontamination cycles in any of the techniques tested. For a more in-depth look at the data, see the 

supplementary tables in the appendix of this report. Each of the 19 supplementary tables presents 

filtration efficiency, manikin fit factor, and strap force change data for a separate decontamination 
13

technique. Thus, evaluation of a convenience sample of 1,354 N95 FFR units across 29 models found 

that 42% of the decontamination techniques evaluated (8 of 19) negatively impacted fit and/or 

filtration efficiency.

The strap integrity evaluation results were largely mixed. The observed percent changes in tensile force 

between decontaminated and control straps, including both positive and negative changes within and 

between tested techniques. However, commercial steamer and DiKlor-G® sterilization did seem to 

result in increased strap tensile force compared with controls. Interpretation and potential translation 

of these results should consider that it is still unclear if observed changes in strap tensile force has a 

downstream influence on FFR fit. Therefore, further examination into this test technique and the 

impact on FFR fit is warranted.

Respirator manufacturers were made aware of the webpage of test results.

For some of the decontamination techniques that NIOSH tested, the FDA used these results in the

evaluation of new decontamination technique EUA applications and to update or revoke existing EUAs. 

NIOSH testing provided decontamination technique developers and service providers with laboratorybased data to ascertain the impact of their techniques on respirator performance.

Further Considerations for Decontamination and Reuse of Filtering 

Facepiece Respirators

• Healthcare organizations should review the FDA EUAs prior to incorporating decontamination

techniques into a respiratory protection program. Only the FDA EUA approved techniques can

be used in healthcare settings.

• The respirator manufacturer should be consulted about any impact that the decontamination

technique has on their respirators before considering the use of any technique. Only respirator

manufacturers can reliably provide guidance on how to decontaminate their specific models.

• Decontamination and subsequent reuse of FFRs is a crisis strategy that should only be

implemented during severe FFR shortages and no conventional or contingency strategies are

viable. Decontamination is not consistent with NIOSH approved use of respirators.

• Decontamination does not extend the life of a respirator and repeated donnings will reduce

the fit factor of an FFR. FFRs may have fit failures after five donnings.2

• If you are contemplating incorporating decontamination techniques into your respiratory

protection program as part of a crisis strategy, you should review the NIOSH Respirator

Decontamination Assessment Results webpage, the Center for Disease Control and Prevention

(CDC) webpage on Implementing Filtering Facepiece Respirator (FFR) Reuse, Including Reuse

after Decontamination, When There Are Known Shortages of N95 Respirators, and OSHA’s

Coronavirus Disease (COVID-19) | Occupational Safety and Health Administration.

2 Bergman, Michael S., et al. “Impact of multiple consecutive donnings on filtering facepiece respirator fit.” American 

journal of infection control 40.4 (2012): 375-380.
14

• The fit factor of the FFR may be reduced with repeated donnings and even techniques that may 

not damage the FFR filter may require frequent fit evaluations. A protective approach 

recommended by the CDC is to limit the number of donnings to five and then dispose of the 

FFRs. Even with guidance on the maximum recommended number of donnings, it is important 

to thoroughly inspect a respirator each time it is used and discard it if it is soiled, damaged, 

difficult to breathe through, or you are unable to pass a seal check – even if it has not been 

used the maximum number of times specified by the CDC or the manufacturer.

• The effect of decontamination techniques on the security of the strap attachment to the mask 

was not completed in these assessments and should be considered in the future.

• The effect of decontamination technique was summarized across various FFR models consisting 

of differing product materials in this report. Consideration of the effect on individual FFR 

models and materials may be important to consider in the future. 

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websites. All web addresses referenced in this document were accessible as of the publication date. 

Suggested Citation

NIOSH [2021] PPE CASE: Assessment of Filter Penetration Performance and Fit for Decontaminated N95 Respirators by

Quinn, T., Bergman M., Strickland, K., Streeter, R., Vollmer, B., Meyers, J., Wilson, A., Pollard, J.P. Pittsburgh, PA U.S. 

Department of Health and Human Services, Centers for Disease Control and Prevention, National Institute for Occupational 

Safety and Health, NPPTL Report Number P2021-0101.
Appendix A. Supplementary Tables

Supplementary Table 1 – Aerosolized Peracetic Acid (PAA) results for filtration efficiency, manikin fit, and strap performance by model

Dose Number 

of Cycles

Respirator

Model

% with ≥95% 

filtration efficiency

% with manikin fit 

factor ≥100

% change in top strap 

tensile force from control

% change in bottom strap 

tensile force from control

76 min x 1.06% PAA 

solution

1 cycle 3M 1860 100% (n=5) 100% (n=3) 2.68 ± 3.78% (n=3) 1.83 ± 1.16% (n=3)

3 cycles 3M 1860 100% (n=5) 100% (n=3) 0.42 ± 2.26% (n=3) 2.60 ± 1.72% (n=3)

5 cycles 3M 1860 100% (n=5) 100% (n=3) 3.27 ± 2.89% (n=3) 1.01 ± 4.38% (n=3)

Supplementary Table 2 – Chlorine Dioxide Gas results for filtration efficiency, manikin fit, and strap performance by model

Dose Number 

of Cycles

Respirator

Model

% with ≥95% 

filtration efficiency

% with manikin 

fit factor ≥100

% change in top strap tensile 

force from control

% change in bottom strap 

tensile force from control

1000–2000 ppm-hr

5 cycles 3M 8000 --- 100% (n=5) -10.25 ± 1.41% (n=3) -6.14 ± 0.75% (n=3)

10 cycles 3M 8000 --- 100% (n=5) -15.04 ± 3.63% (n=3) -6.15 ± 2.59% (n=3)

20 cycles 3M 8000 100% (n=10) 80% (n=5) -7.86 ± 2.10% (n=3) -4.72 ± 2.54% (n=3)

2,500 ppm-hr 4 cycles 3M 8200 100% (n=4) --- -11.56 ± 2.38% (n=4) -7.11 ± 1.98% (n=4)

850 ppm-hr 5 cycles 3M 8200 100% (n=10) 100% (n=5) -6.69 ± 2.78% (n=3) -11.04 ± 3.88% (n=3)

720 ppm-hr

1 cycle 3M V-Flex 1805 100% (n=10) 100% (n=4) 0.54 ± 5.52% (n=3) 9.82 ± 3.21% (n=3)

4 cycles 3M 1860 100% (n=10) 100% (n=5) 15.26 ± 6.17% (n=3) 18.38 ± 10.93% (n=3)

VWR 89201-508 100% (n=10) 0% (n=5) -6.15 ± 6.78% (n=3) -5.57 ± 4.66% (n=3)

“---” indicates that no test was performed.

Supplementary Table 3 – Commercial Steamer results for filtration efficiency, manikin fit, and strap performance by model

Dose Number 

of Cycles

Respirator

Model

% with ≥95% 

filtration efficiency

% with manikin fit 

factor ≥100

% change in top strap tensile 

force from control

% change in bottom strap 

tensile force from control

30 seconds at 100°C 10 cycles 3M 8210 100% (n=10) 100% (n=5) 7.82 ± 1.02% (n=4) 10.86 ± 2.10% (n=4)

Supplementary Table 4 – DiKlor-G® Sterilization, Chlorine Dioxide results for filtration efficiency, manikin fit, and strap performance by model

Dose Number 

of Cycles

Respirator

Model

% with ≥95% 

filtration efficiency

% with manikin fit 

factor ≥100

% change in top strap tensile 

force from control

% change in bottom strap 

tensile force from control

800 ppm-hr 6 cycles 3M 8210 100% (n=10) 100% (n=5) 15.14 ± 1.07% (n=3) 16.05 ± 1.47% (n=3)

Not reported 6 cycles 3M 1860 100% (n=10) 100% (n=5) 11.70 ± 0.75% (n=3) 12.00 ± 4.65% (n=3)
16

Supplementary Table 5 – Dry Heat (commercial laundry dryer) results for filtration efficiency, manikin fit, and strap performance by model

Dose Number 

of Cycles

Respirator

Model

% with ≥95% 

filtration efficiency

% with manikin fit 

factor ≥100

% change in top strap tensile 

force from control

% change in bottom strap 

tensile force from control

90 min at 80-85°C 3 cycles

3M 1860 100% (n=10) 100% (n=5) -1.74 ± 1.72% (n=3) -3.23 ± 2.31% (n=3)

3M 8511 100% (n=10) 100% (n=5) -4.76 ± 5.58% (n=3) -3.70 ± 3.18% (n=3)

Halyard 62126 100% (n=10) 100% (n=5) -4.38 ± 2.11% (n=3) -3.28 ± 0.84% (n=3)

70 min at 80-85°C 3 cycles

3M 1860 100% (n=10) 100% (n=5) -6.56 ± 2.36% (n=3) -2.53 ± 1.47% (n=3)

3M 8511 100% (n=10) 100% (n=5) -12.09 ± 1.82% (n=3) 9.73 ± 0.53% (n=3)

Halyard 62126 100% (n=10) 100% (n=5) -4.60 ± 1.13% (n=3) -5.23 ± 1.79% (n=3)

Supplementary Table 6 – Dry Heat (environmental chamber) results for filtration efficiency, manikin fit, and strap performance by model

Dose Number 

of Cycles

Respirator

Model

% with ≥95% 

filtration efficiency

% with manikin fit 

factor ≥100

% change in top strap tensile 

force from control

% change in bottom strap 

tensile force from control

60 min at 75°C 5 cycles

3M 1860 100% (n=7) 100% (n=3) -4.31 ± 1.28% (n=5) -1.23 ± 2.05% (n=5)

3M 1870+ 100% (n=7) 100% (n=3) 9.44 ± 1.93% (n=5) 1.43 ± 1.89% (n=5)

Halyard 46717 100% (n=7) 100% (n=3) -4.03 ± 0.62% (n=5) -5.26 ± 1.39% (n=5)

45 min at 75°C 10 cycles

3M 1860 100% (n=10) 100% (n=5) -5.62 ± 4.13% (n=4) 0.11 ± 3.81% (n=4)

3M 1860S 100% (n=10) 100% (n=5) -8.71 ± 2.08% (n=4) -5.79 ± 2.06% (n=4)

3M 1870+ 100% (n=10) 100% (n=5) 3.25 ± 3.44% (n=4) -1.28 ± 3.13% (n=4)

3M 8210+ 100% (n=10) 50% (n=10) -0.40 ± 3.22% (n=3) 3.00 ± 3.05% (n=3)

3M 9205+ 100% (n=10) 100% (n=5) 5.90 ± 3.60% (n=4) 6.83 ± 3.59% (n=4)

3M V-Flex 1804 100% (n=10) 80% (n=5) -4.82 ± 1.79% (n=4) 0.59 ± 1.78% (n=4)

Supplementary Table 7 – Electron Beam Irradiation results for filtration efficiency, manikin fit, and strap performance by model

Dose Number 

of Cycles

Respirator

Model

% with ≥95% 

filtration efficiency

% with manikin fit 

factor ≥100

% change in top strap 

tensile force from control

% change in bottom strap 

tensile force from control

25 kGy/cycle

1 cycle 3M 8200 0% (n=4) --- -0.40 ± 8.38% (n=4) -1.29 ± 4.81% (n=4)

2 cycles 3M 8200 0% (n=3) --- 11.78 ± 8.96% (n=3) 0.99 ± 5.05% (n=3)

3 cycles 3M 8200 0% (n=3) --- 14.65 ± 3.25% (n=3) 7.20 ± 2.77% (n=3)

“---” indicates that no test was performed.
17

Supplementary Table 8 – Gaseous Ozone results for filtration efficiency, manikin fit, and strap performance by model

Dose Number 

of Cycles

Respirator

Model

% with ≥95% 

filtration efficiency

% with manikin fit 

factor ≥100

% change in top strap 

tensile force from control

% change in bottom strap 

tensile force from control

450 ppm 5 cycles 3M 1870 100% (n=5) --- -0.23 ± 22.58% (n=3) -5.32 ± 17.3% (n=3)

“---” indicates that no test was performed.

Supplementary Table 9 – Gravity Steam results for filtration efficiency, manikin fit, and strap performance by model

Dose Number 

of Cycles

Respirator

Model

% with ≥95% 

filtration efficiency

% with manikin fit 

factor ≥100

% change in top strap 

tensile force from control

% change in bottom strap 

tensile force from control

30 min at 121°C 3 cycles

3M 1860 100% (n=5) 0% (n-2) 9.85 ± 1.48% (n=3) 2.11 ± 2.1% (n=3)

3M 1870 100% (n=5) 100% (n=2) -21.57 ± 0.74% (n=3) -5.71 ± 4.97% (n=3)

3M V-Flex 1905 100% (n=5) 100% (n=2) 1.33 ± 5.49% (n=3) -13.8 ± 3.99% (n=3)

Supplementary Table 10 – Methylene Blue results for filtration efficiency, manikin fit, and strap performance by model

Dose Number 

of Cycles

Respirator

Model

% with ≥95% 

filtration efficiency

% with manikin fit 

factor ≥100

% change in top strap 

tensile force from control

% change in bottom strap 

tensile force from control

10μM spray 

(~7mL/cycle) + 100k 

lux light for 60 mins

5 cycles

3M 1860 100% (n=7) 100% (n=3) -3.67 ± 3.61% (n=5) 1.91 ± 3.83% (n=5)

3M 1860S 82% (n=11) 100% (n=4) -4.47 ± 2.34% (n=3) 4.88 ± 4.76% (n=3)

3M 1870+ 100% (n=7) 100% (n=3) 3.53 ± 10.21% (n=5) 14.37 ± 3.78% (n=5)

Halyard 46727 100% (n=7) 100% (n=2) -1.40 ± 0.76% (n=5) -1.48 ± 1.55% (n=5)

Supplementary Table 11 – Microwave generated plasma results for filtration efficiency, manikin fit, and strap performance by model

Dose Cycles 

Tested

Respirator

Model

% with ≥95% 

filtration efficiency

% with manikin 

fit factor ≥100

% change in top strap 

tensile force from control

% change in bottom strap 

tensile force from control

45 seconds 3 cycles

3M 1860 100% (n=5) 100% (n=2) -0.20 ± 1.37% (n=3) -5.68 ± 0.55% (n=3)

3M 8210 80% (n=5) 50% (n=2) -2.25 ± 2.17% (n=3) -8.69 ± 3.73% (n=3)
18

Supplementary Table 12 – Moist Heat results for filtration efficiency, manikin fit, and strap performance by model

Dose Number 

of Cycles

Respirator

Model

% with ≥95% 

filtration efficiency

% with manikin fit 

factor ≥100

% change in top strap 

tensile force from control

% change in bottom strap 

tensile force from control

60 min at 100°C & 

100%RH

1 cycle 3M 1860 100% (n=3) 0% (n=5) -5.29 ± 2.69% (n=3) -8.58 ± 1.48% (n=3)

3 cycles 3M 1860 100% (n=3) 0% (n=5) -5.84 ± 1.47% (n=3) -11.43 ± 0.85% (n=3)

5 cycles 3M 1860 100% (n=3) 0% (n=5) -5.10 ± 4.37% (n=3) -10.40 ± 1.73% (n=3)

15 min at 85°C & 

65%RH

1 cycle 3M 1860 100% (n=4) 33% (n=3) 1.89 ± 1.19% (n=4) -1.73 ± 2.84% (n=4)

3 cycles 3M 1860 100% (n=4) 33% (n=3) 2.28 ± 2.79% (n=4) -0.15 ± 2.96% (n=4)

5 cycles 3M 1860 100% (n=4) 33% (n=3) 2.75 ± 2.70% (n=4) 1.02 ± 1.56% (n=4)

Supplementary Table 13 – Plasma Discharge Reactive Oxygen Species results for filtration efficiency, manikin fit, and strap performance by model

Dose Number 

of Cycles

Respirator

Model

% with ≥95% 

filtration efficiency

% with manikin 

fit factor ≥100

% change in top strap 

tensile force from control

% change in bottom strap 

tensile force from control

500 ppm-min

1 cycle BYD DE2322 100% (n=3) --- -3.55 ± 1.19% (n=3) -4.75 ± 4.38% (n=3)

Prestige Ameritech RP88020 100% (n=3) --- 4.21 ± 5.4% (n=3) 3.79 ± 6.39% (n=3)

3 cycles BYD DE2322 100% (n=3) --- 1.93 ± 1.76% (n=3) -4.87 ± 2.47% (n=3)

Prestige Ameritech RP88020 100% (n=3) --- 1.73 ± 1.96% (n=3) 2.44 ± 4.05% (n=3)

“---” indicates that no test was performed.

Supplementary Table 14 – Sterrad NX100 HPV/Low Temp Plasma results for filtration efficiency, manikin fit, and strap performance by model

Dose Cycles 

Tested

Respirator

Model

% with ≥95% 

filtration efficiency

% with manikin 

fit factor ≥100

% change in top strap tensile 

force from control

% change in bottom strap 

tensile force from control

Not reported 2 cycles

3M 8511 100% (n=10) 40% (n=5) -3.37 ± 5.88% (n=3) 3.62 ± 3.42% (n=3)

Halyard 46727 100% (n=10) 80% (n=5) -5.61 ± 2.57% (n=3) -5.62 ± 3.00% (n=3)

Supplementary Table 15 – Stryker STERIZONE VP4 Sterilizer results for filtration efficiency, manikin fit, and strap performance by model

Dose Number 

of Cycles

Respirator

Model

% with ≥95% 

filtration efficiency

% with manikin 

fit factor ≥100

% change in top strap tensile 

force from control

% change in bottom strap 

tensile force from control

Pre-set cycle

(Cycle 1), 41°C 5 cycles

3M 1860 100% (n=7) 100% (n=3) 27.52 ± 10.45% (n=5) 33.79 ± 8.57% (n=5)

3M 1870+ 100% (n=7) 100% (n=3) 11.95 ± 2.25% (n=5) 11.86 ± 4.56% (n=5)

Halyard 46727 100% (n=7) 100% (n=3) -17.20 ± 2.74% (n=5) -18.75 ± 1.44% (n=5)
19

Supplementary Table 16 – Supercritical Carbon Dioxide results for filtration efficiency, manikin fit, and strap performance by model

Dose Number 

of Cycles

Respirator

Model

% with ≥95% 

filtration efficiency

% with manikin 

fit factor ≥100

% change in top strap 

tensile force from control

% change in bottom strap 

tensile force from control

60 min at 37°C & 1100 psig 10 cycles 3M 1860 0% (n=10) 80% (n=5) -0.89 ± 1.42% (n=3) 2.17 ± 2.04% (n=3)

90 min at 37°C 1 cycle

3M 1860 0% (n=4) 0% (n=2) 9.38 ± 1.57% (n=4) 8.73 ± 4.53% (n=4)

3M 1860S 0% (n=5) 0% (n=2) 5.62 ± 0.79% (n=4) 10.16 ± 0.35% (n=4)

3M V-Flex 1804 0% (n=4) 100% (n=2) 1.55 ± 5.44% (n=4) 10.26 ± 3.12% (n=4)

Supplementary Table 17 – Ultraviolet Germicidal Irradiation (UVGI) results for filtration efficiency, manikin fit, and strap performance by model

Dose Number 

of Cycles

Respirator

Model

% with ≥95% 

filtration efficiency

% with manikin fit 

factor ≥100

% change in top strap tensile 

force from control

% change in bottom strap 

tensile force from control

UV-C 254nm

1000 mJ/cm2 10 cycles 3M 1860 100% (n=5) 100% (n=2) -1.09 ± 2.33% (n=3) -3.97 ± 4.12% (n=3)

3M 8210 100% (n=3) 100% (n=2) 1.85 ± 0.69% (n=3) 1.36 ± 1.66% (n=3)

UV-C 254nm

500 mJ/cm2

1 cycle 3M 1860S 100% (n=5) --- -0.84 ± 1.66% (n=3) 2.57 ± 1.50% (n=3)

3 cycles 3M 1860S 100% (n=5) --- 0.17 ± 2.86% (n=3) 1.47 ± 4.54% (n=3)

5 cycles 3M 1860S 100% (n=5) --- 5.12 ± 1.09% (n=3) 7.62 ± 2.32% (n=3)

10 cycles 3M 1860 100% (n=5) 100% (n=1) --- ---

3M 8210 100% (n=3) 100% (n=1) 5.65 ± 6.90% (n=3) 0.16 ± 2.48% (n=3)

“---” indicates that no test was performed.

Supplementary Table 18 – UVGI and Infrared Heat results for filtration efficiency, manikin fit, and strap performance by model

Dose Number 

of Cycles

Respirator

Model

% with ≥95% 

filtration efficiency

% with manikin fit 

factor ≥100

% change in top strap tensile 

force from control

% change in bottom strap 

tensile force from control

90 min at 175°C 3 cycles Halyard 46767 100% (n=10) 100% (n=5) 3.16 ± 2.05% (n=3) -0.89 ± 1.94% (n=3)

5 cycles Halyard 46767 0% (n=10) 0% (n=3) 1.14 ± 1.32% (n=4) -0.75 ± 1.43% (n=4)
20

Supplementary Table 19 – Vapor Phase Hydrogen Peroxide (VPHP) results for filtration efficiency, manikin fit, and strap performance by model

Dose Number 

of Cycles

Respirator

Model

% with ≥95% 

filtration efficiency

% with manikin 

fit factor ≥100

% change in top strap tensile 

force from control

% change in bottom strap 

tensile force from control

25 min at 45°C with 

35% HP

10 cycles Makrite 9500-N95S 100% (n=5) 100% (n=3) -6.59 ± 1.07% (n=5) -2.60 ± 3.12% (n=5)

20 cycles Makrite 9500-N95S 60% (n=5) 33% (n=3) -4.05 ± 2.85% (n=5) 0.13 ± 3.65% (n=5)

30 cycles Makrite 9500-N95S 100% (n=5) 0% (n=3) -8.62 ± 4.41% (n=5) -11.63 ± 1.29% (n=5)

3 hours at 7%

1 cycle

3M 8000 100% (n=4) 0% (n=1) --- ---

3M 8210 100% (n=3) 100% (n=2) --- ---

3M 8210V 100% (n=3) 100% (n=2) --- ---

Crosstex GPRN95 100% (n=4) 0% (n=1) --- ---

Moldex 1512 100% (n=3) 100% (n=2) --- ---

2 cycles

3M 8000 100% (n=5) --- --- ---

3M 8210 100% (n=3) 100% (n=2) --- ---

3M 8210V 100% (n=3) 100% (n=2) --- ---

Crosstex GPRN95 100% (n=5) --- --- ---

Moldex 1512 100% (n=3) 100% (n=2) --- ---

3 cycles

3M 8000 100% (n=5) --- --- ---

3M 8210 100% (n=3) 100% (n=2) --- ---

3M 8210V 100% (n=3) 100% (n=2) --- ---

Crosstex GPRN95 100% (n=5) --- --- ---

Moldex 1512 100% (n=3) 100% (n=2) --- ---

4 cycles

3M 8000 100% (n=5) --- --- ---

3M 8210 100% (n=3) 100% (n=2) --- ---

3M 8210V 100% (n=3) 100% (n=2) --- ---

Crosstex GPRN95 100% (n=5) --- --- ---

Moldex 1512 100% (n=3) 100% (n=2) --- ---

5 cycles

3M 8000 100% (n=5) --- --- ---

3M 8210 100% (n=3) 100% (n=2) --- ---

3M 8210V 100% (n=3) 100% (n=2) --- ---

Crosstex GPRN95 100% (n=5) --- --- ---

Moldex 1512 100% (n=3) 100% (n=2) --- ---

“---” indicates that no test was performed.
21

Supplementary Table 19 Continued – Vapor Phase Hydrogen Peroxide (VPHP) results for filtration efficiency, manikin fit, and strap performance by model

Dose Number 

of Cycles

Respirator

Model

% with ≥95% 

filtration efficiency

% with manikin 

fit factor ≥100

% change in top strap tensile 

force from control

% change in bottom strap 

tensile force from control

Not Reported

5 cycles

3M 1860 100% (n=5) 100% (n=2) --- ----

3M 1860S 100% (n=3) 100% (n=3) 21.38 ± 2.50% (n=3) 16.49 ± 2.58% (n=3)

3M 8210 100% (n=5) 100% (n=2) -1.22 ± 2.05% (n=3) -12.98 ± 1.93% (n=3)

3M 8511 100% (n=10) 100% (n=5) 13.10 ± 1.16% (n=3) 24.85 ± 2.69% (n=3)

3M 9205+ 100% (n=10) 100% (n=5) -10.32 ± 1.50% (n=3) -19.52 ± 2.67% (n=3)

3M V-Flex 1804 100% (n=5) 100% (n=2) 7.40 ± 6.19% (n=3) 8.78 ± 2.48% (n=3)

Gerson 1730 100% (n=10) 100% (n=4) -3.78 ± 4.83% (n=3) -3.95 ± 2.28% (n=3)

Gerson 1740 100% (n=10) 75% (n=4) -14.24 ± 5.05% (n=3) -4.50 ± 6.58% (n=3)

Moldex 1512 100% (n=8) 100% (n=4) -11.32 ± 2.74% (n=3) -9.49 ± 4.28% (n=3)

Moldex 2200 100% (n=8) 50% (n=4) 4.91 ± 1.09% (n=2) -5.01 ± 8.72% (n=2)

Sperian N1105 100% (n=10) 100% (n=5) 7.31 ± 3.01% (n=3) 24.03 ± 3.06% (n=3)

Sperian N1125 100% (n=10) 80% (n=5) 9.32 ± 2.82% (n=3) 18.69 ± 11.41% (n=3)

Sperian One-Fit 100% (n=15) --- -0.50 ± 20.48% (n=3) -1.52 ± 7.74% (n=3)

10 cycles

3M 1860 100% (n=10) 100% (n=5) 17.25 ± 0.82% (n=3) 37.67 ± 3.10% (n=3)

3M 8210 100% (n=10) 100% (n=5) 0.54 ± 1.69% (n=3) -10.08 ± 1.95% (n=3)

3M 8511 100% (n=10) 100% (n=5) 15.25 ± 12.15% (n=3) 23.43 ± 1.35% (n=3)

3M 9205+ 100% (n=10) 100% (n=5) -14.04 ± 2.78% (n=3) -18.26 ± 5.25% (n=3)

3M V-Flex 1804 100% (n=10) 80% (n=5) 25.76 ± 5.50% (n=3) 22.73 ± 3.62% (n=3)

Gerson 1730 100% (n=10) 100% (n=5) -19.68 ± 3.49% (n=3) -16.38 ± 7.29% (n=3)

Gerson 1740 100% (n=10) 25% (n=4) -4.38 ± 3.81% (n=3) 5.86 ± 6.81% (n=3)

Moldex 1512 100% (n=10) 100% (n=5) -10.01 ± 2.86% (n=3) -11.80 ± 2.84% (n=3)

Moldex 2200 90% (n=10) 100% (n=5) 10.43 ± 3.74% (n=3) -11.23 ± 3.42% (n=3)

Sperian N1105 100% (n=10) 100% (n=5) 10.53 ± 5.41% (n=3) 4.54 ± 8.55% (n=3)

Sperian N1125 100% (n=10) 80% (n=5) 9.41 ± 4.80% (n=3) -4.54 ± 7.70% (n=3)

Sperian One-Fit 100% (n=10) --- 18.45 ± 14.87% (n=3) -3.63 ± 19.95% (n=3)

“---” indicates that no test was performed.
22

Supplementary Table 19 Continued – Vapor Phase Hydrogen Peroxide (VPHP) results for filtration efficiency, manikin fit, and strap performance by model

Dose Number 

of Cycles

Respirator

Model

% with ≥95% 

filtration efficiency

% with manikin 

fit factor ≥100

% change in top strap tensile 

force from control

% change in bottom strap 

tensile force from control

Not Reported

15 cycles 3M 1860 100% (n=10) 100% (n=5) 22.42 ± 2.24% (n=3) 42.93 ± 5.96% (n=3)

20 cycles

3M 1860 100% (n=10) 100% (n=5) 24.85 ± 1.62% (n=3) 39.06 ± 8.30% (n=3)

3M 1870+ 100% (n=6) 100% (n=4) -15.29 ± 3.99% (n=3) -17.81 ± 2.00% (n=3)

3M 8210 100% (n=10) 100% (n=5) -6.14 ± 0.90% (n=3) -16.65 ± 3.57% (n=3)

3M 8511 100% (n=10) 100% (n=5) 18.06 ± 11.48% (n=3) 0.10 ± 4.19% (n=3)

3M 9205+ 100% (n=10) 100% (n=5) -18.73 ± 4.06% (n=3) -19.30 ± 3.16% (n=3)

3M V-Flex 1804 100% (n=10) 80% (n=5) 6.04 ± 7.71% (n=3) 5.94 ± 3.97% (n=3)

Gerson 1730 100% (n=10) 100% (n=5) 0.13 ± 9.31% (n=3) -5.33 ± 4.14% (n=3)

Gerson 1740 100% (n=10) 100% (n=5) 1.27 ± 2.81% (n=3) -8.83 ± 11.35% (n=3)

Moldex 1512 100% (n=10) 100% (n=5) -14.49 ± 2.20% (n=3) -15.53 ± 2.60% (n=3)

Moldex 2200 100% (n=10) 80% (n=5) 1.38 ± 6.31% (n=3) 3.84 ± 4.88% (n=3)

Sperian N1105 100% (n=10) 80% (n=5) 5.56 ± 4.54% (n=3) -10.25 ± 7.76% (n=3)

Sperian N1125 100% (n=10) 40% (n=5) 0.24 ± 3.07% (n=3) -6.42 ± 3.19% (n=3)

Sperian One-Fit 100% (n=10) --- 3.62 ± 23.37% (n=3) 17.98 ± 5.19% (n=3)

“---” indicates that no test was performed.
APPENDIX B. N95 FFR PERFORMANCE EVALUATION METHODS

Particulate Filter Efficiency Testing 

The maximum and minimum penetration value will be reported for the set of 10 respirators. If valves are 

present on the respirator, they will be sealed for testing. Each respirator will be tested on a TSI 8130 and/or 

8130A Automated Filter Tester, set to the following parameters:

a. The flow rate will be set to 85.0 ± 4.0 Liters/Minute.

b. Aerosol concentration will not exceed 200 mg/m3

.

c. The particle size distribution will be 0.075 ± 0.020 micrometer with a geometric standard deviation not 

exceeding 1.86.

d. Each respirator will be tested for 10 minutes.

e. Maximum penetration will be recorded for each individual respirator

While some of the test parameters listed are consistent with NIOSH Standard Test Procedure TEB-APR-STP-0059 

(STP-0059) 1

, this modified test is different. Respirators assessed to this modified test plan do not meet the 

requirements of STP-0059, and therefore cannot be considered equivalent to N95 respirators that were tested 

to STP-0059. The values reported are only to provide an indication of filter efficiency following 

decontamination. 

Static Advanced Headform Fit Evaluation 

Static fit testing will be completed using a static advanced headform (StAH). A medium size StAH (Hanson 

Robotics Inc., Plano, TX) (corresponding to the medium size dimensions of the NIOSH Principal Component 

Analysis Panel), will be used to assess the static fit of respirators. Depending on the size of the respirator 

received and the perception of fit on the medium sized headform, a large sized StAH (Lunar Studios, Wylie, TX) 

may also be used. Overall manakin fit factor (mFFO) will be determined for 5 respirators that were subjected to 

decontamination procedures and an additional 2 control respirators that are new and were not 

decontaminated. This evaluation includes the assessment of mFFO using the below-described methodology.

The static advanced headform fit testing and tensile strength testing will be used to determine the 

anticipated changes in fit. The stress of the straps following the decontamination procedure will be compared to 

1 NIOSH Standard Test Procedure: https://www.cdc.gov/niosh/npptl/stps/pdfs/TEB-APR-STP-0059-508.pdf
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that of the control respirators that did not undergo the decontamination technique. Therefore, the results of 

this testing will show any changes in tensile strength due to the decontamination technique. Likewise, the 

change in the overall manikin fit factor will be reported.

Headform Donning 

Respirators will be donned to the headform following the respirator manufacturers’ guidance for correct 

headstrap placement and adjustment of the bendable noseclip (for models so equipped). Manikin fit factor 

evaluations are performed utilizing a “screening” technique that was developed to quickly evaluate the seal of 

the respirator to the face of the StAH prior to beginning the actual fit factor evaluation. The screening technique

first involves donning the respirator onto the StAH and making adjustments to the noseclip and head straps. 

Then, with the breathing machine operating at 11.2 lpm, the test operator observes a graphic display of realtime fit factors (FF) on the PortaCount® screen (real-time FF mode) where FFs are output approximately 1 per 

second. If the real-time output shows 10-consecutive FFs ≥ 100, then the test operator begins the actual fit 

factor evaluation. If not, the respirator is doffed, re-donned, adjusted, and reevaluated in real-time FF mode. Fit 

factor evaluations are started after the third attempt if fit criteria is not met after three attempts.

Headform Breathing 

Respirator fit will be evaluated for the StAH under cyclic breathing conditions. The tube extending from the 

bottom of the StAH is connected to an inflatable (non-latex, powder-free) bladder inside an isolated, airtight, 

plastic cylinder. This configuration prevents any particles potentially generated by the simulator from entering 

the breathing zone of the StAH. A port on the cylinder is connected to a Series 1101 breathing simulator (Hans 

Rudolf, Inc., Shawnee, KS).

Two minute-volumes are used for manikin fit factor evaluation: normal breathing (14 breaths / min 

(bpm) x 800 ml tidal volume = 11.2 lpm) and deep breathing (12 bpm x 1700 ml tidal volume = 20.4 lpm). The 

use of only two exercises (normal and deep breathing) differs from the standard OSHA-accepted PortaCount® fit 

test which also includes dynamic movements and a speaking passage. Therefore, fit results from this assessment 

cannot be directly translated to using the standard OSHA-accepted test.

Manakin Fit Factor 

Manikin fit factor (mFF) will be measured on the StAH using a PortaCount® Pro+ model 8038 Respirator 

Fit Tester (TSI, Inc., Shoreview, MN) operating in the N95-enabled mode. The PortaCount® utilizes condensation 

nuclei counting technology to enumerate individual particles and calculate a quantitative respirator mFF. The 
25

test agent used will be ambient room aerosol supplemented with generated sodium chloride aerosol. A noncommercial software will automate the fit factor data collection. 

An individual fit factor evaluation includes three successive 86-sec exercises: an initial normal breathing 

exercise (NB1), a deep breathing exercise (DB), and then a second normal breathing exercise (NB2). Each 86-sec 

exercise consists of four PortaCount® actions: ambient purge (6 sec), ambient sample (15 sec), mask purge (15 

sec), and mask sample (50 sec). Four mFFs are obtained for each test—one for each of the three exercises and 

an overall exercise (mFFO), calculated as the harmonic mean of the mFFs from the three individual exercises.

Tensile Testing of Elastomeric Straps 

Straps will be removed from 5 respirators as required for particulate filter efficiency testing. These straps include 

the top and bottom straps from 3 respirators that were subjected to the decontamination process and 

additional top and bottom straps from 2 control respirators that are new and have not undergone any 

decontamination process. The integrity of these elastomeric head straps will be assessed using an Instron 5943 

tensile tester as follows. 

1. Straps will be sectioned into 10-cm segments, with ~15 mm on each side to be clamped. 

2. Straps will be inserted into the Instron and pulled at 1 cm/s until 200% strain (30 cm sample length) is 

reached.

3. This “pre-stretching” position will be held for 2 minutes. 

4. Straps will be returned to their original position for 5 minutes and the new segment length will be 

measured after the 5 minutes. 

5. Straps will be pulled at 1 cm/s until reaching 150% strain of the new length. This 150% strain position 

will be held for 30 seconds and the force at the end of the 30 seconds will be recorded.