When filters or chemical cartridges are left in the open air with contaminants present in the air, the service life of the filters or cartridges can be compromised. Particulate contaminants can build up on the surface of the filter or adversely affect the electrostatic charge in the filter if so designed. Cartridges may also absorb vapor or gas contaminants and thereby have their service lives reduced. Air is not being drawn through the filters or cartridges in this environment, but the filtering efficiency can still be reduced.

Always story the filters and cartridges in a clean, uncontaminated environment. Always enclose the filters or cartridges in the original and new plastic bags with the ends folded over to protect them from the ambient air even though it is deemed to be clean.