3 ms·

I've seen this a couple of places, but no-one has explained why the masks expire? Also - it should be possible to design simple protocols to rotate the stock p

• dsfyu404ed 7y ago
  Like most non-organic things masks "expire" because the manufacture needs to not be liable after a certain date (after all, the manufacturer can't be realistically held responsible indefinitely) and the institutions buying the masks are unwilling to take on the responsibility of determining the quality of their own stockpile so they just trash them and buy more. The military actively researches this kind of thing and knows exactly how long past it's expiration date many products are good for. I'm unaware of any other organizations that take on this responsibility.
• ckcheng 7y ago
  I found: "Over time, components such as the straps and nose bridge material may degrade, which can affect the quality of the fit and seal" [1] Also, some filters are constructed from charged fibers and electrostatic attraction helps in the filtering [2]. I wonder if that electrostatic attraction can be lost in some way, which would help explain the expiry date. Anyway, [1] also says using expired masks may be considered in a crisis, best for training and fit testing though. [1] https://www.cdc.gov/coronavirus/2019-ncov/hcp/respirators-strategy/crisis-alternate-strategies.html https://www.cdc.gov/coronavirus/2019-ncov/hcp/respirators-st... [2] https://blogs.cdc.gov/niosh-science-blog/2009/10/14/n95/ https://blogs.cdc.gov/niosh-science-blog/2009/10/14/n95/