These were stored in a tool box in our warehouse. They were not exposed to the elements. The 3M TR-6530N Versaflo Organic Vapor/Acid Gas/HEPA Cartridge is a high-quality replacement cartridge designed specifically for use with 3M TR-600/800 PAPR systems. Made in Canada, this cartridge is equipped with a filter class that efficiently captures organic vapor, acid gas, and HEPA particles, providing safe and reliable protection for users in various industrial and medical settings. With a unit quantity of 1, this cartridge ensures long-lasting performance and ensures a clean and comfortable breathing environment for the wearer.