Gas masks, as personal protective equipment, are used to provide effective protection for personnel's respiratory organs, eyes, and facial skin. The mask consists of a face mask, an air duct, and a canister. The face mask can be directly connected to the canister or connected to the canister through an air duct. Gas masks can be selected from various types of filter canisters according to protection requirements, and are used in chemical, warehouse, scientific research, and various toxic and harmful work environments.

According to the principle of protection, gas masks can be divided into filter type gas masks and isolation type gas masks.

Composed of a face mask and a canister (or filter element). The face mask includes components such as the mask body, eye window, communicator, breathing valve, and headband (or helmet). The filter canister is used to purify toxic gases and contains a filter layer and adsorbent. These two materials can also be mixed to make a filter plate and assembled into a filter element. The lighter (around 200 grams) filter canister or filter element can be directly attached to the mask, while the heavier filter canister is connected to the mask through an air duct.

Gas masks are mainly used to block toxic gases produced through the respiratory tract, such as cyanide chloride (CK), chloropicrin (PS), etc; It also has a certain effect on the protection against biological toxins. After the entry into force of the Convention on the Prohibition of Chemical Weapons, the demand for gas masks temporarily decreased; But with the strengthening of counter-terrorism operations, the threat of potential chemical attacks still exists, and gas masks are still important equipment for chemical protection, with a considerable amount of equipment in various countries.

In addition, people working in toxic and harmful gas environments are also using gas masks as protection; But the structure of general civilian gas masks is not as complex as military ones, and various indicators are not as strict as military ones. Design more appearances for civilian chemical protection to meet the needs of different groups of people.