Protective (Gas) Masks

The Washington National Guard Museum has an extensive collection of original protective (gas) masks. Protective masks were originally known as gas masks as they were designed to protect against battlefield chemical agents. While today’s masks have some similarities in design and function, modern masks are designed to protect against a more complex set of liquid and aerosol agents.

Gas masks became standard military equipment during the First World War due to the widespread use of chemical agents beginning in 1914. Arriving in France in late 1917, US Armed Forces had no gas masks so several hundred thousand masks were purchased from the French and British. 

Corrected English Model (CEM)

The CEM is a modified version of the English Small Box Respirator (SBR). Full scale production started in January 1918 with about 1.6 million manufactured between January and March 1918. The CEM was available in six sizes (1 through 6) and was one of two most commonly worn American made gas masks during the war.

Although the appearance of the mask was very similar to the SBR, American industry made the following changes:

  • Facepiece was cut fuller to make it more comfortable
  • Mask was made more durable with the use of rubberized sailcloth
  • Facepiece was impermeable to known chemical agents used by the German Army
  • Eyepieces were made using laminated glass and celluloid. Lamination prevented leaking of gas even if the eyepieces were cracked
  • Filter canister size was changed to improve filtration capabilities
  • Nose-clip was changed to improve comfort

The CEM was standard issue until replaced by the M1 Service Gas Mask in 1921.

M1 Service Gas Mask

The M1 Service Gas Mask was based on an experimental WW1 design known as the Kops Tissot Monro (KTM). The mask came in five sizes, had fixed round eyepieces and was a made from rubberized sailcloth like the CEM.

In 1934, the improved model M1A1 was adopted. It was also available in five sizes, included replaceable lenses and other minor changes.

In 1935, the M1A2 mask was adopted with a one-size stockinet-covered rubber mask.

M1 series Service Masks served from 1921 until 1944.

M2A1 Service Gas Mask

The M2A1 mask started as the M1 Training mask developed in 1939. It was the first mask to have a fully molded rubber facepiece. The success of the M1 Mask resulted in it being standardized in 1941 as the M2A1 Service Gas Mask. While the M1 Training Mask used a cylindrical canister attached directly to the mask, the M2A1 had the filter at the end of a house like the M1 Service Mask. Three sizes were available for the M2A1 – small, universal and large.

Additional changes resulted in the M2A2 in 1942 and M2A3 in 1944. Over 8 million M2A series masks were produced during WW2 before becoming obsolete in 1949.

A design flaw with the M2A series mask resulting in fogging issues. Fogging issues and a heavy filter led to the development of the M3 series and M4 series masks.

M6 Dog Gas Mask

During WW2, the US Army experimented with several styles of dog gas masks before adopting the M6 Dog Gas Mask. The mask covered the snout and eyes of the dog. One M12 filter is attached to each side of the mask below the eye piece. Total production was limited to 1,409 masks during WW2. In 1968, only 32 dog masks were available and they were in poor condition leading to obsolete status in 1969.