A gas mask is a piece of protective clothing that covers the wearer’s head and face to reduce the effects of dangerous gases. It protects against toxic vapors and particles, but it cannot prevent radiation or other harmful substances from reaching the body through the skin or lungs. The mask is used by soldiers, emergency responders, and industrial workers.
The earliest gas masks were created to protect against poisonous chemicals, such as chlorine gas used by German forces in the Battle of Ypres in 1915. They were not designed for use in combat, however, and many Allied soldiers who did not have their own masks died.
To use a gas mask correctly, the chin is pushed well forward into the mask, and the elastics are drawn over the head as far as they will go. The mask will then form a snug fit around the chin and mouth. The mask must be fitted properly in order to work effectively, but it is difficult to find a size that fits all wearers of a particular type. This is especially true for people with facial deformities, or those with a very large nose.
The main factors affecting the effectiveness of a gas mask are the aerosol particle size, type, and gas flow. Other factors include the fit of a mask and the penetration of particles through the filter. The relationship between filtration efficiency and the facial seal leakage of a mask is also discussed, and existing problems and future development trends are presented.