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Evaluation of Decontaminated N95 Respirators 

Date Tested: 8/19/2020 – 8/26/2020 

Respirator Model(s): 3M 8200, Prestige Ameritech RP88020, and BYD DE2322 

Tests: Filtration with NaCl (modified version of STP-0059) and Strap Integrity with Tensile Testing 

Decontamination Method: Respirator model 3M 8200 was decontaminated using an Electron Beam Irradiation method. 

Both the Prestige Ameritech RP88020 and BYD DE2322 respirator models were decontaminated using a Plasma Discharge 

reactive oxygen species (ROS) method, which involved a surface dielectric barrier discharge technique for plasma ROS 

generation. 

Decontamination Cycles: 1 cycle (Electron Beam Irradiation); 1 cycle and 3 cycles (Plasma Discharge ROS) 

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). 

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

evaluation. This included 1 respirator that was subjected to 1 cycle of the electron beam irradiation 

decontamination process, 6 respirators subjected to 1 cycle of the plasma discharge ROS decontamination 

method, 6 respirators subjected to 3 cycles of the plasma discharge ROS decontamination method, and an 

additional 7 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. 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 respirator subjected to electron beam irradiation (1 cycle) measured an 

efficiency less than 95%. All samples treated with plasma discharge ROS (1 and 3 cycles) measured efficiencies 

greater than 95%. See Table 1. 

Strap Integrity Results: No visual degradation of the straps was observed. The sample treated with electron 

beam irradiation (1 cycle) showed a decrease in recorded force. The Prestige Ameritech RP88020 treated with 

plasma discharge ROS (1 and 3 cycles) showed an increase in recorded force. The BYD DE2322 treated with 

plasma discharge ROS showed a decrease in recorded force at 1 cycle and mixed results between top and 

bottom straps at 3 cycles. See Table 2. 
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Figure 1A. TSI 8130 Filter Tester Figure 1B. Instron 5943 Tensile Tester

A

B
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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.

• 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 

(%)

3M 8200, control Control 1 85 12.0 1.10 1.11 98.89

3M 8200, Electron 

Beam Irradiation, 1 

cycle

1 85 12.3 36.4 36.4 63.6

Prestige Ameritech 

RP88020, control

Control 9 85 7.6 0.657 0.657 99.34

Control 10 85 7.4 2.21 2.21 97.79

Control 11 85 7.8 1.34 1.38 98.62

Prestige Ameritech 

RP88020, Plasma 

Discharge ROS, 1 

cycle

Min Fil Eff: 99.35%

Max Fil Eff: 99.56%

1 85 7.5 0.468 0.483 99.52

2 85 7.6 0.425 0.441 99.56

3 85 7.7 0.649 0.649 99.35

Prestige Ameritech 

RP88020, Plasma 

Discharge ROS, 3 

cycles

Min Fil Eff: 99.50%

Max Fil Eff: 99.59%

5 85 7.7 0.400 0.414 99.59

6 85 7.4 0.442 0.470 99.53

7 85 7.7 0.495 0.502 99.50

BYD DE2322, control

Control 9 85 14.0 2.35 2.35 97.65

Control 10 85 13.0 1.53 1.53 98.47

Control 11 85 14.7 1.75 1.75 98.25

BYD DE2322, Plasma 

Discharge ROS, 1 

cycle

Min Fil Eff: 97.79%

Max Fil Eff: 98.04%

1 85 10.8 2.21 2.21 97.79

2 85 13.5 1.96 1.96 98.04

3 85 14.4 2.21 2.21 97.79

BYD DE2322, Plasma 

Discharge ROS, 3 

cycles

Min fil Eff: 97.10%

Max Fil Eff: 98.69%

5 85 15.4 1.31 1.31 98.69

6 85 13.3 2.90 2.90 97.10

7 85 14.1 2.24 2.24 97.76
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Table 2. 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)

3M 8200, control Control 1 4.682 4.888

3M 8200, Electron Beam 

Irradiation, 1 cycle

1 4.116 4.520

% Change

((Deconned - Controls) / Controls) -12.1% -7.53%

Prestige Ameritech RP88020, 

control 

Control 9 2.574 3.010

Control 10 2.663 2.798

Control 11 2.514 2.937

Control Strap Average 2.584 2.915

Prestige Ameritech RP88020, 

Plasma Discharge ROS, 1 cycle

1 2.553 2.876

2 2.693 2.966

3 2.832 3.234

Decontaminated Strap Average 2.693 3.025

% Change

((Deconned - Controls) / Controls) 4.22% 3.77%

Prestige Ameritech RP88020, 

Plasma Discharge ROS, 3 cycles

5 2.687 3.079

6 2.600 3.026

7 2.599 2.853

Decontaminated Strap Average 2.629 2.986

% Change

((Deconned - Controls) / Controls) 1.74% 2.44%

BYD DE2322, control

Control 9 4.564 4.628

Control 10 5.501 4.736

Control 11 4.666 5.005

Control Strap Average 4.910 4.790

BYD DE2322, Plasma Discharge 

ROS, 1 cycle

1 4.721 4.506

2 4.686 4.387

3 4.800 4.795

Decontaminated Strap Average 4.736 4.563

% Change

((Deconned - Controls) / Controls) -3.54% -4.74%

BYD DE2322, Plasma Discharge 

ROS, 3 cycles

5 4.915 4.492

6 5.012 4.485

7 5.087 4.693

Decontaminated Strap Average 5.005 4.557

% Change

((Deconned - Controls) / Controls) 1.93% -4.86%