A gas mask refers to a protective chemical absorbent air filtration system. The chemical absorbent, in most cases, is activated charcoal, and works like a sponge for chemicals. To block out small particles, “a high efficiency particulate air filter (HEPA) is what is needed, similar to a surgeon’s mask. A military gas mask offers a huge advantage for the soldiers who want protection against chemical attacks. You can check out modern military grade gas mask on https://www.gasmaskpro.com/gas-masks
The advantages of having a gas mask is that you can set a poisonous gas off towards the enemy more closer than you usually could before it is exposed freely into the air. Then the soldier would simply put on the gas mask and once the gas is exposed he run through the gas and start killing off the enemy as they are either blinded or being affected heavily by/from the gas due to them having the disadvantage.
Various government agencies, including the Centers for Disease Control and the Defense Department have tested gas masks to be sure they meet HEPA standards. Because chemical and biological agents can spread very quickly, experts agree that for a gas mask to be effective, timing is everything.
In a chemical attack, you must have it at your side to make a difference. Microorganisms would most likely be in the air without our knowledge, so the only way to protect oneself would be to wear the mask for 24 hours a day, seven days a week.