United States Marine Corps Weapons & Equipment
M40/42 Chemical/Biological Protective Masks
Primary function: Provides respiratory, eye, and face protection against
field concentrations of chemical and biological agents.
Protects against: Chemical and biological agent vapors, aerosols, toxins, and radiological fallout particles.
Protection probabilities:
95% against 5,000 mg-min/m3
75% against 20,000 mg-min/m3
50% minimum probability of achieving no more than .002 percent penetration of Bacillus globigii.
Breathing resistance: not greater than 55mm of water at 85 liter/min
Unit Replacement Cost: $157
Features: The M40/42 series field protective masks will replace the M17 (general purpose), M25 (vehicle crewman),
and M9 (heavy duty) masks. The M40/42 masks consist of a silicone rubber face piece with an in-turned peripheral
face seal and binocular rigid lens system. A face-mounted canister (gas and aerosol filter) can be worn on either
the left or the right cheek, and withstand a maximum of 15 nerve, choking, and blister agent attacks. It will also
withstand a maximum of 2 blood agent attacks. Biological agents do not degrade the filter. The mask is furnished
in small, medium, and large sizes. It provides the user with unobstructed and undistorted forward vision, and corrective
lenses can be obtained. The mask also permits intelligible speech, does not interfere with hearing and provides
for a drinking capability while being worn. Because of these features, the mask can be worn continuously for 8
to 12 hours. Microphone air adapters will be provided for combat vehicle and aircraft applications.
Inventory: The Acquisition Objective is 277,069. 87% (241,714) of the AO will be met with current funding through
FY 95.
Information and Photos Courtesy of United States Marine Corps
