A gas-particulate filter canister includes a filter canister body and first and second canister end caps secured to opposing ends of the filter canister body. First and second filter cartridges are supported within the filter canister body for filtering a gas in series. The filter cartridges can be standalone units which are built independently and are installed into the filter canister body. The filter cartridges can be concentrically arranged and can include a particulate filter cartridge and a gas filter cartridge.