I did some quick internet search for information on whether it is safe to use expired face masks or they lose efficacy and I got mixed results. I didn't find any post in this forum about this topic either.
I guess it should be alright to use face masks (at least surgical masks or FFP2) even long after they have expired -naively, I don't see why they should degrade- but then why do they have the expiry dates. Is it something any EA organization has looked at? I haven't found any.
My thought is that masks are probably one of the easiest and cheapest ways to prepare for a future pandemic, but keeping a large stock (be it personally or by states, for example) is a waste of money and impractical if they expire after a few years and have to be replaced. So it may be a simple yet effective issue to look at for an EA organization.
If they do degrade, it doesn't look like it should be too difficult to find a way to cheaply produce masks that keep their properties for at least several decades, ideally a century or two. So, it may not be too difficult to get regulators to mandate that masks must comply with such standards, for example. And if they don't degrade, it may be possible to push for getting rid of expiry dates or making them more accurate. Of course, producers may not be happy with this, but the gains would be significant.
Really long-lasting face masks would allow for the storage of really large quantities, enabling a quick response when needed.
