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Evaluation of Decontaminated N95 Respirators 

Date Tested: 10/19/2020 – 10/21/2020 

Respirator Model(s): Halyard Fluidshield 46767 Regular 

Tests: Filtration with NaCl (modified version of STP-0059), Manikin Fit Factor with Static Advanced Headform, and Strap 

Integrity with Tensile Testing 

Decontamination Method: The Clean Sleep Hyperion is a closed, free-standing mobile chamber specifically designed for 

sanitizing soft surfaces. The Hyperion’s proprietary technology utilizes UVC light and infrared heat. In independent 

laboratory tests, using an FDA approved protocol, the Hyperion eliminated 99.9% of viruses and bacteria on N95 

respirators. Each cycle has a time duration of 90 minutes at a temperature of 175°F. 

Decontamination Cycles: 3 cycles 

While decontamination and reuse of FFRs are not consistent with standard and approved usage, these options 

may need to be considered when FFR shortages exist. This assessment was developed to quantify the filtration 

efficiency and manikin fit factor1 of an N95 respirator that has been decontaminated. This assessment is not to 

determine the effectiveness of the decontamination procedure at killing pathogenic microorganisms. The results 

provided in this report are specific to the subset of samples that were provided to NPPTL for evaluation. These 

results may be used to update the CDC guidance for Crisis Capacity Strategies (during known shortages). 

Twenty respirators that were unworn and not subjected to any pathogenic microorganisms were submitted for 

evaluation. This included 15 respirators that were subjected to 3 cycles of the UVC light/infrared heat 

decontamination process and an additional 5 respirators that served as controls. Figure 1 photos document the 

procedures used. The samples were tested using a modified version of the NIOSH Standard Test Procedure 

(STP) TEB-APR-STP-0059 to determine particulate filtration efficiency. The TSI, Inc. model 8130 using sodium 

chloride aerosol was used for the filtration evaluation. For the laboratory fit evaluation, a static manikin 

headform was used to quantify changes in manikin fit factor. The TSI, Inc. PortaCount® PRO+ 8038 in “N95 

Enabled” mode was used for this evaluation. Additionally, tensile strength testing of the straps was performed 

to determine changes in strap integrity. The Instron® 5943 Tensile Tester was used for this evaluation. The full 

assessment plan can be found here. 

Filtration Efficiency Results: The minimum and maximum filter efficiencies were 97.89% and 99.62%, 

respectively. All ten respirators measured efficiencies greater than 95%. See Table 1. 

Manikin Fit Factor Results: The manikin fit factor showed passing fit factors (greater than 100) for all respirators 

evaluated. The manikin fit test procedure used in this assessment did not show any detriments in fit associated 

with the decontamination method used. See Table 2. 

Strap Integrity Results: Inconsistent changes were shown between the top and bottom straps, with the top 

straps showing a 3.16% increase in recorded force and the bottom straps showing a 0.90% decrease in force. 

See Table 3. 

1The American Industrial Hygiene Association defines the Manikin Fit Factor as “An expression related to the amount of leakage measured through the 

face or neck seal of a respirator mounted to a manikin under specified airflow and environmental conditions. If the challenge to the seal is an airborne 

substance, it is the ratio of its airborne concentration outside the respirator divided by the concentration that enters the respirator through the seal. If the 

challenge is airflow or air pressure, conditions and assumptions for quantifying leakage must be specified. Leakage from other sources (e.g., air purifying 

elements) must be essentially zero. The respirator may be mounted to the manikin without sealants; be partially sealed to the manikin; or be sealed to the 

manikin with artificially induced leaks.” 
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Figure 1. Laboratory Test Photos

1A 1B

Fig 1A. Large Static Advanced Headform Fig 1B. TSI 8130 Filter Tester 

1C

Fig 1C. Instron 5934 Tensile Tester 
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Table 1. Filter Efficiency Evaluation

Notes:

• The test method utilized in this assessment is not the NIOSH standard test procedure that is used for certification 

of respirators. Respirators assessed to this modified test plan do not necessarily meet the requirements of STP0059, and therefore cannot be considered equivalent to N95 respirators that were tested to STP-0059. 

Respirator Model, 

Decon Method, # of 

cycles

Treated 

Sample #

Flow 

Rate

(Lpm)

Initial Filter 

Resistance

(mmH2O)

Initial Percent 

Leakage (%)

Maximum 

Percent 

Leakage (%)

Filter 

Efficiency 

(%)

Halyard Fluidshield 

46767 Regular, 

controls

Control 1 85 12.3 0.483 0.493 99.51

Control 2 85 12.0 0.496 0.497 99.50

Control 3 85 12.8 0.541 0.541 99.46

Halyard Fluidshield

46767 Regular, 

UVC light/infrared 

heat, 3 cycles 

Min Fil Eff: 97.89%

Max Fil Eff: 99.62%

1

85 12.3 0.465 0.465 99.54

2

85 12.6 0.601 0.601 99.40

3

85 15.1 0.518 0.518 99.48

4

85 16.2 0.437 0.437 99.56

5

85 12.9 0.724 0.724 99.28

6

85 12.6 1.130 1.13 98.87

7

85 13.8 2.010 2.11 97.89

8

85 13.7 0.444 0.444 99.56

9

85 13.1 0.370 0.384 99.62

10 85 12.9 0.845 0.845 99.16
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Table 2. Manikin Fit Evaluation

Manikin Fit Factor of Decontaminated N95s

Respirator Model, 

Decon Method, # of 

cycles

Treated

Sample #

mFF Normal 

Breathing 1

mFF Deep 

Breathing

mFF Normal 

Breathing 2

Overall 

Manikin Fit 

Factor

Halyard Fluidshield 

46767 Regular, 

controls

Large Static 

Advanced Headform

(Lunar Studio)

Control 4 200+ 200+ 200+ 200+

Control 5 200+ 191 200+ 197

Halyard Fluidshield 

46767 Regular, UVC 

light/infrared heat, 3 

cycles

Large Static 

Advanced Headform 

(Lunar Studio)

11 200+ 200+ 200+ 200+

12 200+ 200+ 200+ 200+

13 200+ 200+ 200+ 200+

14 200+ 167 200+ 188

15 200+ 200+ 200+ 200+

Notes:

• Per OSHA 1910.134(f)(7), if the fit factor as determined through an OSHA-accepted quantitative fit testing protocol 

is equal to or greater than 100 for tight-fitting half facepieces, then the fit test has been passed for that respirator.

• This assessment does not include fit testing of people and only uses two exercises (normal and deep breathing) on 

a manikin headform. 

• This assessment is a laboratory evaluation using a manikin headform and varies greatly from the OSHA individual 

fit test. This headform testing only includes normal breathing and deep breathing on a stationary (non-moving) 

headform; therefore, fit results from this assessment cannot be directly translated to using the standard OSHAaccepted test. Instead, this testing provides an indication of the change in fit performance (if any) associated with 

the decontamination of respirators. 
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Table 3. Strap Integrity Evaluation

Tensile Force in Respirator Straps of Decontaminated N95s

(recorded force values are at 150% strain)

Respirator Model, Decon 

Method, # of cycles

Straps from Treated Sample 

#

Force in Top 

Strap (N)

Force in Bottom 

Strap (N)

Halyard Fluidshield 46767 

Regular, controls

Control 1 2.275 2.317

Control 2 2.169 2.314

Control 3 2.267 2.333

Control Strap Average 2.237 2.321

Halyard Fluidshield 46767 

Regular, UVC light/infrared heat, 

3 cycles

1 2.288 2.346

2 2.360 2.256

3 2.275 2.299

Decontaminated Strap 

Average 2.308 2.300

% Change

((Deconned - Controls)/ 

Controls)

3.16% -0.90%