Chemical Gas Mask Quality Control

Gas masks, and air purifying respirators in general, are regulated by the Code of Federal Regulations (CFR). These regulations specify the type of masks to use for a specific application. Examples of the different mask types recognized by the CFR include self-contained breathing apparatus, non-powered air purifying particulate respirators, chemical cartridge respirators, and dust masks. The regulations stipulate the exact kind of testing that must be done to ensure the quality of the finished product. The type of testing depends on the masks' final application, that is, what kind of contaminants it will be expected to filter. The CFR specifies the types of contaminants that the gas must be tested with, and it also stipulates the conditions under which the testing must be conducted. For example, some masks must be exposed to the contaminant for long periods of time. Others must be tested under specific temperature and humidity conditions. This is done by drawing an air stream contaminated with a known amount of poison through the mask. The amount of time required for the contaminant to saturate the filter and begin to pass through is then measured.

Testing is done at several points in the manufacturing process. There is an initial inspection of incoming goods to ensure they meet minimum quality specifications. This includes the filtrants, the resins used for molding, and the finished eyepieces as they are received. The canister must be tested after assembly to ensure it has proper seal and that the carbon filter works. The gas  mask is tested once again after all componentry has been assembled. The final mask may be placed on a mannequin head to ensure that the seal is tight and that the mask maintains its seal in movement.