NPPTL Respirator Assessments to Support the COVID-19 Response

Beyond Shelf Life/Stockpiled Respirator Assessment

In 2017, NIOSH established a Personal Protective Equipment (PPE) Stockpile Partnership to inform the design and execution of studies to evaluate stockpiled air-purifying respirators. As part of this partnership, NIOSH obtained samples of N95 respirators and determined their inhalation and exhalation resistance and filtration performance. Since completing this examination, and due to the current respirator shortage associated with COVID-19, NPPTL has received several requests to assess the performance of stockpiled respirators that are beyond their designated shelf life or have been subjected to prolonged storage.

NPPTL staff is conducting a limited assessment to determine the particulate filter efficiency of N95 respirators that are beyond their designated shelf life or subject to prolonged storage using NIOSH Standard Test Procedure TEB-APR-STP-0059pdf icon (STP-0059). All NIOSH-approved N95 respirators are approved using STP-0059. As such, this assessment will allow NPPTL to assess the particulate filter efficiency of NIOSH-approved N95s that are beyond the manufacturer-supplied shelf life date or subjected to long-term storage conditions. Several models of N95s were examined as part of the NIOSH Stockpile Study. Respirators included in that study will not be evaluated in this assessment. Please visit to determine if your respirators were included in the previous study.

If you are interested in having NPPTL assess the filtration performance of your stockpiled/beyond shelf life N95s, that were not included in the previous assessment, please complete the following form. If assessment of multiple models of respirators is being requested, this form should be completed for each model.

Page last reviewed: October 29, 2020