NPPTL COVID-19 Response: Beyond Shelf Life/Stockpiled Respirator Assessment

Manufacturer: 3M

Model Tested: 1870 (TC-84A-3844)

Date Tested: July 27, 2020

Report Prepared: July 27, 2020

These findings pertain to the 3M, model 1870 (TC-84A-3844) submitted for testing; and may not be 

applicable to other stockpile facilities and/or under different environmental storage conditions. The 

maximum and minimum filter efficiency was 99.89% and 99.30%, respectively. All twenty respirators

measured more than 95% efficiency. There was no designated expiration date.

NIOSH regulation sets the minimum quality and performance requirements for the approval of 

respirators (42 CFR 84). NIOSH does not have requirements for shelf life or storage conditions for 

particulate-only APRs. The approval holder (i.e. the entity that is granted the approval from NIOSH) is 

responsible for understanding how their products’ design or performance may be affected by various 

use or storage conditions and must provide instruction for establishing the proper use, storage, and 

maintenance procedures for their approved products, which may include designating a shelf life. FFR 

or particulate filter packaging (such as the box) often includes NIOSH-approved user instructions, label 

information, and recommendations on shelf life. Additionally, some approval holders also disseminate 

recommendations related to storage and shelf life through resources such as user and web notices. 

The respirators tested in this study were generally not designed for long-term storage. 

Based on research conducted by NIOSH and this limited testing, NIOSH does not have enough 

information to definitively know the level of protection that may be provided by respirators that 1) are 

stored for prolonged periods of times; 2) are stored under various storage conditions; or 3) have 

exceeded the approval holder’s designated shelf life. Users of respirators that have exceeded the 

designated shelf life should be forewarned to avoid a false sense of confidence; these devices may not 

provide the same level of protection as those that have not exceeded the designated shelf life. We 

recommend contacting the approval holder(s) of the respirators in the stockpile with specific questions 

regarding the use of product beyond the manufacturer- designated shelf life.

The results provided in this letter are specific to the subset of NIOSH-approved N95s, past their 

designated shelf life, that were provided to NPPTL for evaluation.

These results will be added to the CDC guidance for Stockpiled N95 Filtering Facepiece Respirators 

Beyond the Manufacturer-Designated Shelf Life.
NPPTL COVID-19 Response: Beyond Shelf Life/Stockpiled Respirator Assessment

Evaluation of Stockpiled and Beyond

Manufacturer-Designated Shelf Life N95s

Test: TEB-APR-STP-0059

Manufacturer: 3M

Item Tested: 1870 (TC-84A-3844)

Expiration Date: None Provided Manufacture Date: None Provided

Filter

Flow Rate

(LPM)

Initial Filter 

Resistance 

(mmH2O)

Initial Percent 

Leakage

(%)

Maximum 

Percent Leakage

(%)

Filter Efficiency

(%)

1 85 9.9 0.09 0.25 99.75

2 85 9.7 0.13 0.27 99.73

3 85 8.3 0.38 0.42 99.58

4 85 9.4 0.07 0.16 99.84

5 85 9.2 0.11 0.18 99.82

6 85 7.8 0.13 0.25 99.75

7 85 9.9 0.07 0.15 99.85

8 85 9.3 0.10 0.18 99.82

9 85 8.3 0.06 0.11 99.89

10 85 10.6 0.09 0.24 99.76

11 85 9.2 0.09 0.14 99.86

12 85 7.7 0.17 0.31 99.69

13 85 9.1 0.13 0.30 99.70

14 85 9.2 0.11 0.20 99.80

15 85 8.0 0.11 0.20 99.80

16 85 9.7 0.12 0.28 99.72

17 85 9.4 0.10 0.18 99.82

18 85 7.6 0.53 0.70 99.30

19 85 9.6 0.14 0.32 99.68

20 85 8.2 0.09 0.19 99.81

Minimum Filter Efficiency: 99.30 Maximum Filter Efficiency: 99.89
NPPTL COVID-19 Response: Beyond Shelf Life/Stockpiled Respirator Assessment
NPPTL COVID-19 Response: Beyond Shelf Life/Stockpiled Respirator Assessment
NPPTL COVID-19 Response: Beyond Shelf Life/Stockpiled Respirator Assessment
NPPTL COVID-19 Response: Beyond Shelf Life/Stockpiled Respirator Assessment
NPPTL COVID-19 Response: Beyond Shelf Life/Stockpiled Respirator Assessment
NPPTL COVID-19 Response: Beyond Shelf Life/Stockpiled Respirator Assessment
NPPTL COVID-19 Response: Beyond Shelf Life/Stockpiled Respirator Assessment
NPPTL COVID-19 Response: Beyond Shelf Life/Stockpiled Respirator Assessment