The gas mask is a device for protection of respiratory organs, eyes and skin from toxic substances, contained in the air we breathe.
Military gas mask protects from radioactive and toxic substances. There are masks filtering and isolating type. Protective effect of filtering gas masks based on the release of air from S and PB during transit through the gas box. The insulating gas mask type (Fig., a) protects against the damaging effects by isolating the respiratory system. The greatest distribution in the troops and civil defense received a gas mask with filter type, they are one of the basic universal means of protection against mass destruction weapons. There are combined (see figure, b)civil (Fig., in) and children (figure, d) filter masks. By design, they differ a little one from another, but the basic scheme of their design and effects on the human body have a lot in common. Military gas mask consists of front and gas boxes connected by a corrugated tube. The gas mask is placed in protivogaznyh bag. The set of mask also includes a steam-free plates, pencil special composition and insulating sleeves points. In the box of the mask has two protective layers: smoke filter and special absorber of - charge. The first of these delays aerosols (smoke, fog) S and PB, and the second S all known in the gaseous state. The filter gas mask does not prevent carbon monoxide. Protection from carbon monoxide provides hopcalite cartridge connected to the box filter respirator cartridge or self-contained breathing apparatus.

Masks and - insulating entrepreneur: 1 - regenerative cartridge, 2 - starting device, 3 - frame, 4 - facial region, 5 - bag, 6 - a breathing bag;
b - combined filter: 1 - gas box, 2 - valve box, 3 - fairing, 4 - glasses, 5 - helmet-mask (front side), 6 - charge, 7 - filter;
in civil - DPP-4: 1 - the front part, 2 - valve box, 3 - connection tube, 4 - gas box;
g - children DP-6: 1 - mask, 2 - ribbon, 3 - back piece, 4 - valve box with expiratory pressure valve 5 - rubber tube, 6 - hole for the flow of air, 7 - gas box, 8 - connection tube, 9 - points.

The front of the respirator consists of rubber helmet-mask or mask with glasses and air - fairing, dyhatelnye and two expiratory valves, providing the distribution of air flows. The front of the mask are the five and three sizes. The size indicated by the number on the chin part of the helmet-mask. The mask has a certain impact on the physiological functions of the person, due to three factors: breathing resistance, hazardous your mask space and action front of a gas mask. The breathing resistance, measured in mm of the water column occurs due to the friction of air passing through a gas mask and largely depends on the speed of air movement. In rest and at low physical activity resistance is small and easily overcome. If the physical work flow area is increasing dramatically, especially on the inhale, and the breathing resistance could reach several hundred millimeters of water column (against tens of millimeters alone). This leads to an overload of the heart, respiratory muscles and fatigue working in a gas mask. To reduce the resistance to breathing and increase length of stay in the gas mask should breathe calmly.
Harmful space - the space between the front part of the gas mask and the surface of the head - in modern filtering gas masks equal to about half the volume of inhaled air alone, military gas mask is 250-300 cm3, child - 50 to 200 cm3. In this space is delayed exhaled air, containing up to 4% of carbon dioxide. When inhaling the gas mask in the lungs mixture of atmospheric air containing small amounts of carbon dioxide, and air your mask space. From the depth of inhalation and magnitude of harmful space depends on the content of carbon dioxide and oxygen in the air we breathe. At a constant value your mask space of a gas mask its adverse effects will be the smaller, the more the depth of inhalation. Therefore, when using a gas mask breathe deeply.
The front part of the gas mask affects the visibility and narrows the field of vision, particularly when the dew points; increased sweating on the skin, long-term contact with rubber; mask renders mechanical pressure that can cause the blood circulation disorders and pain, especially when the wrong selection of the front. The adverse impact of a gas mask on healthy people can be reduced by carrying out systematic training. Application filtering gas masks for protection of the wounded and sick is limited; they are not used for protection of seriously ill with heart disease, hypertension, angina, pneumonia, exudative pleuritis, edema, and tuberculosis of the lungs, stroke, meningitis, the concussion, penetrating wounds to the chest, head injuries, elevated intracranial pressure, coma, collapse. Such sick and wounded should ensure the collective protection means. If no shelters or they depressurized, contraindications for the protection of the wounded and sick using mask not. For a head injury is a special front side (SHR). As a means of protecting infants serves children protective camera (spare wheel bracket), which is a shell (envelope) from airtight fabric stretched over a frame; its volume may reach 50 HP Sealing is done by rolling the side panels at the roller shutter. The air in the camera is supplied with a manual fur through gas box SE-4U. Spare wheel bracket is used only during the transition parents with infants in the shelter.
Industrial filtering gas masks are special boxes of Lignohumate a, B, CD, BKF, etc. designed to trap fumes and aerosols only certain hazardous substances (acid gases, carbon monoxide, hydrogen derived sulfur, nitrogen, phosphorus, arsenic, vapors of organic substances and others). For protection from carbon monoxide is used BMW brand or CO mining filter samostoiatel SP-55 PM dust protection applies dust respirator (see).
Industrial insulating gas masks are also hose gas masks consisting of masks and long rubber hose for air intake from non-infected areas.

The mask-is the means of individual protection of respiratory organs, eyes and skin from exposure to toxic and radioactive substances, bacterial aerosols, as well as toxic vapors, gases, fumes and dust arising under production conditions.
There are masks military and industrial. On device and principle of the protective action of Petrograd divided into filtering and isolating.
In filtering gas mask breathing air coming from the atmosphere, the gas is cleaned in a box from harmful impurities in the processes of adsorption, chemisorption, catalysis and filtering. Breathing in insulating P. carried out in isolation from the external environment through the existing gas mask oxygen and absorber of carbon dioxide from the exhaled air.
Filtering gas mask consists of absorption (gas) box and the front part stacked for storage in a bag (Fig. 1). The set of mask are also anti-fog film or a pencil to protect the glass from fogging and insulating cuff of glasses. Box attached to the front part, directly or through flexible connecting hose. In the box is placed in the charge, consisting of activated carbon - catalyst and chemical absorber, and smoke filter.
The front of the respirator consists of rubber mask (or helmet-mask) with the glasses and valve boxes with dyhatelnye and expiratory valves. The masks are made in several sizes.
Combat filter P. presents army examples of a type of MO-2 (Fig. 1) and samples for the population SE-4U (Fig. 2).
To protect children from 1,5 till 14 years are used baby masks DP-6, and APS-BM, for children under 1.5 years camera protective baby (CPCS). To protect wounded in the head and fired using special helmets SHR in the form of hood (Fig. 3).
Industrial filtering gas masks are special boxes (grades a, b, CD, BKF, and others), designed to trap fumes and aerosols only certain hazardous substances (acid gases, carbon monoxide, hydrogen derivatives of sulfur, nitrogen, phosphorus, arsenic, vapors of organic substances and others). For protection from carbon monoxide is used BMW brand WITH or mining filter samostoiatel SP-55m; in the troops there hopcalite cartridge unit 2.
Dust protection apply dust respirator RP-51, RPP-57, TRB-5, f-57, PB-1 and others (see Respirators).
The negative impact of filtering gas mask on the body due to increasing the breathing resistance, the presence of the front space, where there is a part of exhaled air with excess CO2, limited field of vision, difficulty hearing and speech, the pressure of the front part of Peterhof to the underlying tissues.
Filtering gas mask, somewhat reducing the health, shall not prevent the execution of any work, military and industrial character. Enhance productivity contributes significantly to the training in a gas mask. At low temperatures and wind protection from possible frostbite under the mask of the chin and neck.
Insulating gas masks used if the air is very high concentrations of toxic substances or substances which people absorb guided not filter P., the lack in the atmosphere of oxygen and in submarine works. There are two types of insulating P., differing from each other on the principle of supply of oxygen for breathing - from the cylinder, where it is compressed (Fig. 4), or of peroxide compounds, where it is chemically bound form (Fig. 5). Military P. first type is KIP-5 (Fig. 6), the second type - IP (Fig. 7). The duration of these P. depends on the intensity of exercise, and is a few hours. In production conditions and rescue works are used insulating P. - RCM-1, ALAC-2, ALAC-2m, Ural-1, Lugansk-2, Donbass-2, a similar device to mask KIP-5, but with a great time of protective action (up to 4-6 hours). Insulating samostoiatel PS-5 built by type IE.
In insulating P. person breathing gas mixture with a high content of O2 and CO2, with high humidity and temperature; negative effects on the body also provides the front part P. and resistance to breathing. For efficiency in insulating gas masks, moreover, affect their relatively high weight and bulkiness. Their design is complex.
In order to avoid accidents at work requires strict adherence to the rules of use of gas masks and medical surveillance.
Industrial insulating P. include hose P. (Fig. 8 and 9)consisting of masks and long (from 10 to 50 m) rubber hose for air intake from non-infected areas. Cm. also Sanitary-chemical protection.

masksFig. 1. Filtering gas mask: 1 - gas box; 2 - connection tube; 3 - helmet; 4 - glasses; 5 - the valve box; 6 - rubber stopper; 7 - smoke filter; 8 - batch (bottom layer - chemical absorber, top - activated carbon); 9 - gas bag with shoulder strap.
Fig. 2. Civil gas masks GP-4U: 1 - gas box; 2 - mask; 3-bag.
Fig. 3. Gas helmet for wounded in the head.
Fig. 4. Diagram of the human breathing in the device type KIP-5: 1 - the valve; 2 - tube for the inhaled air; 3 - oxygen tank; 4 - a breathing bag; 5 - regenerative cartridge; 6 - tube for breath.
Fig. 5. Diagram of the human breathing in gas mask type entrepreneur: 1 - regenerative cartridge; 2 - a breathing bag.
Fig. 6. The device oxygen device KIP-5: 1 - valve box; 2 - dyhatelnye corrugated tube; 3 - combined mechanism of oxygen supply; 4 - oxygen tank: 5 - breathing bag; in - regenerative cartridge; 7 - valve overpressure; 8 - expiratory corrugated tube.
Fig. 7. The device insulating gas mask IP-46: 1 - regenerative cartridge with oxygen-containing drug; 2 - starting the device; 3 - frame; 4 - bag; 5 - a breathing bag.
Fig. 8. Hose mask PSH-1 self-priming type.
Fig. 9. Hose mask the AAA-5 with supply air blower.