Purex Filter Shelf-Life
According to the manufactury "We do not allocate a shelf life to Purex filters because if they are kept in sealed
packaging and stored in a dry area there should be no degradation due to
environmental conditions.
Particle filters such as Pads, Labyrinth Bags, HEPAs and Cascades are
fabricated from synthetic polymer or borosilicate (glass like) fibres which are
not subject to oxidation or UV degradation.
The activated carbon blends used for gas removal in Purex filters will adsorb
airborne contaminants over time but their performance should not degrade if
packaged and stored correctly."
Information received 2022-06