MASK FILTER INFO
M13 series: should not be used for NBC protection.
C2: Click here for photo of original (OBSOLETE) C2 container. Racal Filter Technologies of Canada manufactures most of these. The year of manufacture is determined by examining the stamped code on the green can the filters come packed in and is two digits after the letters RFT (or MST, for very early C2s). Example: RFT94XXXXX was made in 1994, the X is the lot number. The letter immediately following the year is the month of manufacture A=January, B=February, M=December
(I is not used). Example: RFT92D005-006 indicates a manufacture date of April, 1992. Filter itself has a metal body painted black with lot number usually stamped in white or yellow ink. If left sealed in the green can under reasonable storage conditions the shelf life should be between 10 and 18 years. Realistically expect 9 to 12 years. Click here for information on filter toxicity.
C2A1: Click here to see photo of original C2A1 (most now nearing their expiration dates). Ditto information for C2 filters. Racal and MSA manufacture these. Filter body is anodized green metal with lot number in white, black, or purple-blue ink. The C2A1 however do not contain chromium compounds, but must be disposed of as hazardous waste. Contracts beginning in 2003 are being packaged in high-impact plastic, re-usable cases. Gone are the days of the OD cans with sharp edges. Click here to see the latest issue.
C7: An excellent green-plastic-bodied Racal filter commonly issued to the Canadian armed forces. Introduced in late 1996. Packaged with quick-remove seals in place, sealed in a loose-fitting green foil bag, thus providing two levels of security for freshness. Same dating scheme as C2 series; shelf life expected to be 12 to 15 years. Of special note are these details from the Canadian government: The carbon is impregnated with an organic amine so as to provide protection against field achievable concentrations of toxic organofluorine mask-penetrants, such as PFIB and its congeners. An alkaline pretreatment enhances its shelf-life.
Flodins NBC-37 canister filters (common issue to many European nations and sometimes issued to US forces working with NATO): Date of manufacture is stamped on canister itself in black ink. Filter is flat OD green painted metal. Original filters from the factory are in green cans similar to the C2 series, many militaries repackage them with the plug seals in place in clear plastic bags to save weight in transit. Shelf life should be similar to C2A1. Chemical composition makes these potentially one of the world's best filters, albeit quite difficult to locate.
