Gas Masks

Gas masks are protective devices that are worn over the face to protect the wearer from inhaling dangerous and harmful airborne pollutants, chemicals and toxic gases. They are tight fitting devices that usually seal off the wearer's mouth and nose, but some models can also cover the eyes and other vulnerable parts of the face. However it should not be confused with scuba masks or oxygen masks, which import fresh air from a closed tank.

Working of Gas Masks
The gas masks work by preventing the harmful gases and components from entering the wearer's inside. It does with the help of three different methods.
Filtration: It is the first line of defense of gas masks. Gas masks use replaceable filter with an extremely fine mesh that physically blocks incoming particles like smoke & virus laden powders. However the problem that occurs often with these filters is that they also restrict the flow of clean air.
Absorption: It blocks the vaporized liquid poisons and germs from entering the wearer's airway with the help of absorbent chemicals like activated charcoal. However the capacity of these chemicals to attract the harmful gases is limited. Such type of masks are helpful in factory settings where the nature of pollutants are known.
Chemical Neutralization: This is the final air purification method used for purifying poisonous gases. Gas masks using this method contain a gas or chemical attached under the face plate. The fumes interact with the incoming poison and neutralizes it, making it harmless for respiration. Such methods are used for those masks, which are used in wars. However it creates some unpleasant atmosphere due to the presence of the neutralizing agent.