If I am using a combination cartridge with a PAPR, how do I know when to change the cartridge? Can the cartridge be decontaminated to extend its useful life?

The training you receive in the use of your assigned respirator as part of your employer’s respiratory protection plan will tell you the frequency of cartridge change that has been determined to be appropriate for the conditions in your worksite. The Occupational Safety and Health Administration’s Standard for Respiratory Protection (29 CFR 1910.134) requires employers to implement a change schedule for all cartridges used in the workplace for protection against vapors and gases when there isn't an end-of-service- life indicator on the cartridge. This schedule must be site specific and take into consideration worksite conditions such as humidity, worker breathing rate, as well as the contaminants and their concentrations.

The cartridge can’t be decontaminated (i.e. reconditioned for reuse). The filter media in the cartridge has a finite capacity and the mechanism used to remove the contaminants from the air is usually not reversible.