Medical Aspects of Chemical Warfare (2008) - The Black Vault

Chemical Defense Equipmentquantitatively test protective masks for defects and toassess the fit on any individual. The device providesthe operator with an audible and visual indication ifa component is defective or if the fit does not meetaccepted service-specific standards.The JSMLT currently works with M40 series andMCU-2/P masks. Future capabilities are planned toinclude M42, M45, and the JSGPM. Key features ofthe JSMLT include ability to locate leaks so repair orreplacement decisions can be made; preventive maintenancechecks and services serviceability testing forleakage in the mask, outlet valve, and drink tube; optionto perform a fit test on human subjects with thesame protocol used by the M41 PATS; and two testheads that allow testing for various mask sizes. The USMarine Corps, Air Force, and Navy are current usersof the JSMLT. 14,15M40A1 Chemical-Biological Field MaskThe M40 series chemical-biological (CB) field mask(Figure 17-5) replaced the M17 series mask as the standardprotective mask issued to the US military. Theinner layer of the facepiece is composed of moldedsilicone rubber that fits tightly against the face, and hasan in-turned peripheral seal, which increases comfortand fit. The mask’s two-ridged eye lenses are approximately35% larger than the type used in the M17 series,providing a better field of view. Filtration is providedin the M40A1 mask by one C2A1 filter canister, whichcan be mounted on either cheek. Two canisters may bemounted on both cheeks for special-purpose activitiessuch as explosive ordnance disposal or technical escort.Any other standard-thread canister issued by NATOcountries will fit the M40A1 mask. 14,15Communication is provided by two voicemitters.One is mounted in the front to allow face-to-face communication;the second is located in the cheek to permitthe use of a radio telephone handset. A drinking systemconsists of internal and external drink tubes; the externaltube has a quick-disconnect coupling that connectswith the M1 canteen cap. The system allows personnelto hydrate while wearing the respirator (Figure 17-6). Asix-point, adjustable harness with elastic straps locatedat the forehead, temples, and cheeks comes together ata rectangular head pad for ease of fitting. 14,15The M40A1 mask comes in three sizes: small,Fig. 17-5. The M40A1 chemical-biological field mask.Photograph: Courtesy of the Chemical Casualty Care Division,US Army Medical Research Institute of ChemicalDefense, Aberdeen Proving Ground, Md.Fig. 17-6. The M40A1 chemical-biological field mask withdrinking tube assembly allows the soldier to drink withoutunmasking. Soldiers wearing mission-oriented protectiveposture gear must drink water to prevent heat stress. Thedrinking tube, essentially a flexible straw, couples withthe canteen cap. The user holds the canteen upright andinverted, then sips water through the tube. After every fewsips, the user must blow exhaled air back into the canteento equalize the atmospheric pressure without introducingcontaminated air.Photograph: Courtesy of the Chemical Casualty Care Division,US Army Medical Research Institute of ChemicalDefense, Aberdeen Proving Ground, Md.565