Can a mask be used after its expiration date?
Text updated on 2020-06-08
It is possible to use an expired mask, with little risk but under certain conditions.
Governments are stockpiling hundreds of millions of FFR respirators. These expire 3 to 5 years after they are manufactured. However, when there is a shortage, it is possible to use an expired mask: its filtration and breathability properties are almost always preserved, sometimes even 17 years after manufactured.
Make sure that the mask has not been damaged during storage, that the elastics or straps are strong, and that there are no leaks when you place it on your face (when blow hard through your nose, you must not feel any air coming out). However, the effectiveness of the FFR respirator appears to decrease over time. Therefore, it is not recommended to use a mask more than 17 years after it was manufactured.
As far as surgical masks are concerned, there are no scientific articles available.
Five expired N95 respirator models do not show a drop in filtration efficiency below 95%, nor in breathability below the standard, up to 13 years after manufacture, with 13 years being close to the limit.Lin, T. H., Tseng, C. C., Huang, Y. L., Lin, H. C., Lai, C. Y., & Lee, S. A. (2020). Effectiveness of N95 facepiece respirators in filtering aerosol following storage and sterilization. Aerosol and Air Quality Research, 20, 833-843.
21 models of N95 respirators that have expired (max. 10 years) do not differ from non-expired models in terms of filtration capacity and breathability.Viscusi, D. J., Bergman, M., Sinkule, E., & Shaffer, R. E. (2009). Evaluation of the filtration performance of 21 N95 filtering face piece respirators after prolonged storage. American journal of infection control, 37(5), 381-386.
98% of the 3,971 expired FFR respirators retain their filtration and breathability properties between 7 and 17 years after manufacture.Greenawald, L.A., Moore, S.M., & Yorio, P.L. (2020). Inhalation and Exhalation Resistance and Filtration Performance of Stockpiled Air-Purifying Respirators: Overall Performance of Nearly 4,000 Respirators Sampled from Ten Stockpile Facilities. NIOSH's PPE Case Report - March 25, 2020. Accessed on June 6, 2020.