The Gas Mask GP-5 is a piece of equipment used to protect the wearer against hazardous agents in the air. It is also worn to reduce damage from the Haze Anomaly in Anomalies and is available to players for purchase in the Shop.
Historically, the development of gas masks has been driven by military research and defense requirements. In addition, technological advances have allowed for the production of more advanced masks that have enhanced performance and comfort. While these improvements have led to significant increases in mask filtration efficiency, there are still limitations, particularly regarding the stability of filtration, and difficulty from thermal and moisture perspectives.
Early gas masks consisted of a small box connected by a breathing tube to a mask constructed to fit closely over the mouth and nose. The box contained granules that absorbed poisonous gases, thus filtering the air passing through the tube into the mouth of the wearer.
The most common type of filter is the charcoal-based, cellulose-acetate or phenolic-acetate filter. These are effective in protecting against many noxious gases, including hydrocarbons and cyanide compounds. Moreover, they are also effective against some biological agents.
However, the filtration efficiency of these filters is not constant and depends on various factors such as the aerosol particle size and type. For example, the filtration efficiency decreases with a decreased aerosol particle size and a greater pressure differential. Furthermore, it is important to note that matching (or fitting) issues, electrostatic attraction, and decontamination methods also affect filtration efficiency.