Laboratory testing of expired masks maintain an acceptable filtration performance with less than 2% failing testing in a study of nearly 4,000 masks from 93 lots
Another study assessing stockpiled N95 masks in Taiwan found acceptable filtration up to 13 years post storage
Guidelines indicate that expired N95 respirators should be used before resorting to extended use/reuse
Badea, A; Groot, G; Dalidowicz, M; Miller, L. What evidence is available regarding degradation of N95 respirators/masks? 2020 Nov 20; Document no.: PPE110203 RR. In: COVID-19 Rapid Evidence Reviews [Internet]. SK: SK COVID Evidence Support Team, c2020. 15 p. (CEST rapid review report)