Gas mask - is a device to protect the face, eyes and respiratory organs of human of radioactive and toxic substances, harmful impurities, bacterial agents, which are present in the air in the form of aerosols, gases or vapors.
Gas masks by a principle of protection can be divided into:
- filter gas masks, which clean the air you breathe;
- insulating gas mask (including hose gas masks), which isolates the the respiratory organs from the environment.
By the purpose filter gus masks can be divided into:
Civil and military gas masks are needed for protection against chemical agents, bacterial aerosols and radioactive dust; industrial - for the protection from harmful impurities which evaporate on the production.
Filter gas masks appeared during World War I. Initially gas masks looked like a multi-layer gauze bandages and masks, which were soaked with different liquid substances, that can react with poisonous substances.
Insulating gas mask can provide the best protection of respiratory organs, they are used in a lack of oxygen in the atmosphere and under high gas pollution of atmosphere.
Hose gas mask is an insulating gas mask, which is needed for protection of respiratory system, skin and eyes from harmful substances.
By the method of the air supply hose gas masks can be divided into two types:
- Self priming hose gas masks with air feed through the hose from a clean area;
- Hose gas masks with force-feed of clean air using fans, blowers or the compressed air networks, after its purification.
Hose gas masks have several advantages - they have unlimited time of protective action, and thanks to the overpressure - is excluded ingress of contaminated air.
Hose gas masks are often used in the petroleum refining industry.
Modern gas masks can be characterized by high efficiency, although you can use them to achieve high-quality protection onl, when you will properly select and apply the right kind of gas masks in a particular situation.