On Tue, 08 Sep 2020 00:30:48 -0700, Jeff Liebermann
wrote:

The
catch is that while the shelf life of the filters is 10-20 years, once
the air seal is broken on the filter canister, I believe that the
filter is only good for perhaps one day.

https://surviveafterend.com/how-long-does-a-gas-mask-filter-last/
8 hrs after the seal is broken.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558