Classification of gas masks by the method of protection

Having clarified the situation with the classical classification of gas masks, let's move on to a more complex differentiation. By functionality, gas masks are divided into: - filtering gas masks; - insulating gas masks. The filtering gas mask works on the principle of sucking in contaminated air, processing it through a filtering absorbing box and releasing carbon dioxide through special protected openings after a person inhales. Such gas masks are very popular, due to its long-term use, in emergency situations you can stay in a filtering gas mask for up to 12 hours. Other, less popular, but also useful PPE include self-contained gas masks, based on the breathing of a person inside a gas mask with pre-prepared clean air. They contain a large reservoir of air, which is somewhat reminiscent of a scuba diver's oxygen cylinder. The disadvantage of such a gas mask is that its direct operation should not exceed 3 hours, and of course, walking with such a gas mask is also quite difficult, because when fully loaded, it weighs more than one kilogram.