Evaluation of Decontaminated N95 Respirators 

Date Tested: 10/5/2020 

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. Each cycle has a time 

duration of 90 minutes at a temperature of 175°F. 

Decontamination Cycles: 5 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 5 cycles of the UVC light/infrared heat decontamination process and an 

additional 5 respirators that served as controls. Figure 1 photos show how the samples looked upon arrival. Figure 2 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 61.90% and 93.77%, respectively. All ten 

decontaminated respirators measured less than 95%. See Table 1. 

Manikin Fit Factor Results: The manikin fit factor showed failing fit factors (less than 100) for all decontaminated 

respirators evaluated. Testing stopped after observing manikin fit factor results of <100 for 3 treated samples. See Table 2. 

Strap Integrity Results: Visual discoloration of the decontaminated straps was observed (shown in Fig. 1C). Inconsistent 

changes were shown between the top and bottom straps with the top strap showing a 1.14% increase in recorded force and 

the bottom strap showing a 0.73% decrease in recorded force. See Table 3. 

Note: The decontaminated respirator samples submitted for testing were observed to have significant damage when 

compared to the control submissions. The decontaminated samples were folded/bent, the filter media was flaking off, the 

nosepieces were lifting up from the mask adhesive, and the straps had notable discoloration. Pictures showing the 

comparison between the submitted controls and decontaminated samples are provided in Figures 1 and 2. 

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.” 
Figure 1. Samples (as received)

Fig 1A. Control-Front Fig 1A. Control-Back

Fig 1B. Sample-Front Fig 1B. Sample-Back

Fig 1C. Control Straps (Top), Sample Straps (Bottom)

A A

B B

C
Figure 2. Laboratory Test Photos

Fig 2A. Large Static Advanced Headform-Control Fig 2A. Large Static Advanced Headform-Sample

A A

B C

Fig 2B. Instron 5943 Tensile Tester Fig 2C. TSI 8130 Filter Tester
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.

• BOLD filter efficiencies < 95%.

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 12.6 0.654 0.654 99.35

Control 2 85 14.3 0.212 0.214 99.79

Control 3 85 15.0 0.584 0.627 99.37

Halyard Fluidshield 

46767 Regular, UVC 

light/infrared heat, 5 

cycles 

Min Fil Eff: 61.90%

Max Fil Eff: 93.77%

1

85 9.1 10.1 10.1 89.90

2

85 9.6 6.23 6.23 93.77

3

85 6.9 28.6 28.6 71.40

4

85 6.6 25.6 27.0 73.00

5

85 7.4 20.6 20.6 79.40

6

85 7.1 16.6 16.6 83.40

7

85 5.9 38.1 38.1 61.90

8

85 7.9 16.4 17.6 82.40

9

85 9.5 7.91 7.91 92.09

10 85 10.1 6.85 6.85 93.15
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 4 200 129 142 151

Control 5 136 104 136 123

Halyard Fluidshield 

46767 Regular, UVC 

light/infrared heat, 5 

cycles 

Large Static 

Advanced Headform 

(Lunar Studio)

11 3 2 3 2

12 5 6 7 5

13 3 2 3 2

14 * * * *

15 * * * *

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.

• BOLD overall manikin fit factors < 100.

• * Samples not tested because treated samples 11-13 achieved manikin fit factors <100.
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 2.372 2.326

Control 2 2.395 2.359

Control 3 2.334 2.337

Control Strap Average 2.367 2.341

Halyard Fluidshield 46767 

Regular, UVC light/infrared 

heat, 5 cycles

1 2.386 2.301

2 2.354 2.373

3 2.426 2.307

4 2.410 2.313

Decontaminated Strap 

Average 2.394 2.324

% Change 

((Deconned - Controls)/

Controls)

1.14% -0.73%