A standard gas mask that reduces the devastating effects of nerve and chemical gas inhalation.
  — The Arsenal 

The MK1 Gas Mask is the first gas mask available to players. It is unlocked after players reach the rank of Sergeant First Class/II. It reduces by 40% the harmful effects of all dangerous gases (visible as a purple cloud or haze) encountered by the wearer, such as those caused by the G7A Gas Grenade and environmental hazards on some maps.



  • There is a rumor that sometimes, when going through the vent in Overdose, the mask will stop players from coughing, thus making their appearance unexpected. However, it does not happen very often and is considered a glitch by most players.
  • Like most of the other face gear items, players only get this for looks rather than the benefits. Some players even say it throws off other players mentally.
  • The MK1 Gas Mask is based off the real-life Russian GP-4 Gas Mask made by the Soviet Union. It also appears identical to many WWI gas masks.
  • the MK1 Gas Mask is useful for Cabin Fever and Black Lung because of its great gas protection.
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