The gas mask is a mask used to protect users from inhaling toxic air pollutants and gases. Masks form a closed cover on the nose and mouth, but can also cover the eyes and other soft tissues in the face. Some gas masks are also respirators, although the word gas mask is often used to refer to military equipment (eg a field protective mask). Users of gas masks are not protected from gas that can be absorbed by the skin. Most gas mask filters will last about 24 hours in a nuclear biological chemical situation (NBC).
Toxic substances in the air can be gases (eg, mustard sulfur and chlorine gas) or particulates (such as biological agents). Many gas masks include protection of both types. Gas masks are used in construction to protect against welding fumes, in dismantling to protect against asbestos or other harmful particles, and in the chemical industry when handling hazardous materials, such as in making repair of leaking equipment or cleaning up after spills; workers usually issue a gas mask as a precaution against leakage.
During demonstrations and protests in which tear gas or CS-gas is used by riot police, gas masks are commonly used by police and demonstrators. In addition to serving their functional purpose, gas masks are also used as a symbol in industrial music, with the most prominent example, a drum and bass subgenre called neurofunk. These symbols are used by graffiti labeling because masks protect them from poisonous fumes of paint tubes, and by urban explorers penetrating into environments where hazardous materials, such as asbestos, may exist.
The traditional gas mask style with two small circular eye windows is derived when the only material suitable for this eye window is glass or acrylic; such as the famous fragile glass, the glass eye window should remain small and thick. Later, the discovery of polycarbonate was allowed for gas masks with large full-face windows. Some have one or two filters attached to the face mask while others have large filters connected to a face mask with a hose, which is sometimes confused with the respirator.
Video Gas mask
Principles of construction
Absorption is a process that is drawn into the body or substrate (usually larger), and adsorption is the deposition process on the surface. This can be used to remove particulate and gas hazards. Although some form of reaction may occur, it is not necessary; this method can work at an attractive cost. For example, if the target particle is positively charged, a negatively charged substrate may be used. Examples of substrates include activated carbon, and zeolites. This effect can be very simple and very effective, for example using a damp cloth to cover the mouth and nose while escaping from the fire. Although this method is effective in trapping particulates produced by combustion, it does not filter out harmful gases that may be toxic or that replace the oxygen needed for survival.
Old gas mask security
Gas masks have a limited life span associated with the absorbent capacity of the filter. Once the filter is saturated with hazardous chemicals, the filter stops providing protection and the user may be injured. Most gas masks use an insulating cap above the air intake to prevent the filter from degenerating before use, but protective capability also decreases at the age of the filter or if exposed to moisture and heat. Very old unused gas mask filters from World War II may not be effective at all in protecting users, and may even potentially harm users due to long-term changes in the chemical composition of the filter.
The World War II gas masks contained blue asbestos in their filters. It is not known how long it must be used in the filter. Inhalation of blue asbestos in the factories resulted in the death of 10 percent of labor due to pleural mesothelioma and peritoneum. This number is between 2.5 and 3.2 times the normal incidence of lung cancer or respiratory cancer.
Many stories come from various Russian gas masks and their filters are now common in surplus stores; GP-5 is often considered to have asbestos filters. Filters are made so that asbestos fibers can not be inhaled, if the filter layer is not damaged. Almost all the masks of the Russian Cold War period contain asbestos, however, only those produced before 1972 pose a threat, and even then, mask construction makes it impossible to inhale asbestos if it is not damaged.
Modern gas masks are quite safe and do not use asbestos, but it is still important to be careful when using modern gas masks. Typically, masks that use 40 mm connections are newer designs. Rubber degrades with time, so the new "modern type" mask in the box can be cracked and leaked. In addition, US C2 (black) tubes proved to contain hexavalent chromium: a study by the US Army Chemical Corps showed that the level in the filter was acceptable, but implied vigilance when using, as it was a carcinogen.
Filter classification
The filter is selected according to the toxic compound. Each type of filter protects against certain hazards:
- AX - Low boiling organic compounds (<= 65Ã, Â ° C)
- A - High boiling organic compound (& gt; 65Ã, Â ° C)
- B - Inorganic gases (hydrogen sulfide, chlorine, hydrogen cyanide)
- E - Sulfur dioxide and hydrogen chloride (acid gas)
- K - Ammonia and amines
- CO - Carbon monoxide
- Hg - Mercury
- Reactors - Iodine and methyl iodide (radioactive)
- P - Particles; classified as P1, P2, and P3 according to the elimination efficiency
- ABEK, ABEK-P3, ABEK-HgP3 or other combination filters against various hazards
Particle filters are often incorporated, because in many cases, the hazardous material is mist-shaped, which has been captured by the particle filter before entering the chemical absorber. Filtration can be assisted by air pumps to improve the wearer's comfort. Air filtration is possible only if there is sufficient oxygen in the first place. So when dealing with asphyxia, or when ventilation is bad or danger is unknown, filtering is not possible and air must be supplied from pressurized bottles as in scuba diving. Also, gas masks do not protect against other hazards; for example, corrosive gas can damage the skin, requires full body protection.
Maps Gas mask
Use
Modern masks are usually made of elastic polymers of various sizes. It comes with a variety of adjustable straps that can be tightened to secure the appropriate. Crucially, it is connected to the filter cartridge near the mouth either directly, or through a flexible hose. Some models contain drinking tubes that can be connected to a water bottle. Corrective lens inserts are also available for users who need them.
Masks are usually tested for fit before use. Once the mask is installed, it is often tested by various challenge agents. Isoamyl acetate, synthetic banana flavourant, and camphor are often used as a harmless challenge agent. In the military, tear gas such as CN, CS, and stannic chloride in a room can be used to give users confidence in mask efficiency.
Reactions and exchanges
This principle relies on harmful substances to humans that are usually more reactive than air. This separation method will use some form of substance which is generally reactive (eg acid) or supported by some solid material. An example is synthetic resin. These can be made with various groups of atoms (usually called functional groups) that have different properties. So the resin can be adjusted for certain toxic groups. When the reactive substance comes in contact with the resin, it will be attached to it, removing it from the air stream. It can also be swapped with less harmful substances on this site.
Although it is raw, the hypo helmet is a temporary measure for British troops in the trenches offering at least some protection during a gas attack. As the months pass and poison gas is used more often, more sophisticated gas masks are developed and introduced. There are two main difficulties with gas mask design:
- Users can be exposed to many types of toxic materials. Military personnel are particularly vulnerable to a variety of toxic gases. However, if the mask is for a particular use (such as protection from certain toxic substances in the plant), then the design can be much simpler and lower cost.
- Protection will disappear over time. The filter will be clogged, the substrate for absorption will be filled, and the reactive filter will run out of reactive substances. Thus the user only has the protection for a limited time, and then he must replace the filter device in the mask, or use a new mask.
History and development
Initial respiratory device
According to Popular Mechanics , "Sponges are commonly used in ancient Greece as gas masks..." The first type of rudimentary gas mask was discovered in the 9th century by the Persian brothers Banu Musa in Baghdad, Iraq. They describe it in their Book of Ingenious Devices , especially to protect workers in contaminated wells. In 1785, Jean-FranÃÆ'§ois PilÃÆ' Â ¢ tre de Rozier found a respirator.
An example of a primitive respirator used by miners and introduced by Alexander von Humboldt in 1799, when he worked as a mining engineer in Prussia. There is also a plague-shaped parasitic outpour of birds of doctors filled with spices dating from the seventeenth century. The pioneer of modern gas masks was created in 1847 by Lewis P. Haslett, a device containing elements that allow breathing through noses and funnels, breathe air through ball-shaped filters, and ventilate to exhale air back into the atmosphere. According to First Fact, it states that "a gas mask that resembles a modern type patented by Lewis Phectic Haslett of Louisville, Kentucky who received a patent on June 12, 1849." US Patent # 6,529 issued to Haslett, describes the first "Inhaler or Lung Protector" that filters dust from the air.
The earliest version was built by the Scottish chemist John Stenhouse in 1854 and the physicist John Tyndall in the 1870s. Another early design was "Safety Hood and Smoke Protector" which was discovered by Garrett Morgan in 1912, and patented in 1914. A simple device consisting of a cotton hood with two hoses hanging onto the floor, allowing the wearer to breathe air safely found in there. In addition, a wet sponge is inserted at the end of the hose to filter the air better. It was later modified to include its own air supply, which led to a World War I gas mask.
First World War
The Germans used toxic gas for the first time against the Allied forces at the Second Battle of Ypres, Belgium on April 22, 1915. In an immediate response were cotton wrapped with gauze issued to troops on 1 May. This is followed by the Black Veil Respirator, discovered by John Scott Haldane, who is a cotton soaked in an absorbent solution secured above the mouth using a black cotton veil. Seeking to fix the Black Veil respirator, Cluny MacPherson created a mask made of a chemical absorbent cloth and mounted all over his head. A 50.5 cm canvas tent is ÃÆ'â € Ã, 48Ã,® cm (19.9 Ã, Â ± 18,9Ã, in) lined with chlorine absorbent chemicals, and comes with a transparent mica lens. Macpherson presented his idea to the Anti-Gas Department of the British War Office on May 10, 1915, with a prototype developed soon after. This design was adopted by the British Army and was introduced as British Smoke Hood in June 1915; Macpherson was appointed to the War Office Committee for the Protection of Toxic Gas. More intricate absorbing compounds are added later for further iteration of the helmet (helm PH), to defeat other respiratory toxic gases used such as phosgene, diphosgene and chloropicrin. In the summer and fall of 1915, Edward Harrison, Bertram Lambert and John Sadd developed the Large Box Respirator. This gas tube mask has a can of absorbent material with a hose and was started in February 1916. A short version, Small Box Respirator, was made universal issue from August 1916.
Also in World War I, because dogs were often used on the front lines, a special type of gas mask developed that dogs were trained to wear. Other gas masks were developed during World War I and next time for horses in various units mounted near the front lines. In America, thousands of gas masks are produced for US and Allied forces. Mine Safety Appliances is a major manufacturer. This mask is then used extensively in industry.
Modern masks
Modern gas masks were developed in 1944 by the US Army Chemical Warfare Service. It is made of plastic and rubber material as it greatly reduces weight and bulk, compared to World War I gas masks and puts the user's face more fitting and comfortable. A major improvement is to replace a separate filter tube connected by the hose by a screw filter tube on the side of the gas mask, which can be easily replaced. Also, plastic lenses can be replaced, much help vision.
The development of gas masks has reflected the development of chemical agents in warfare, meeting the need to protect against the more deadly threats, biological weapons, and radioactive dust in the nuclear era. However, where agents causing skin contact or skin penetration occur, such as blister agents or nerve agents, gas masks alone are insufficient protection, and full protective clothing should be worn in addition to protecting from contact with the atmosphere.. For civil defense and personal protection reasons, individuals often purchase gas masks believe that they protect against the harmful effects of an attack with a nuclear, biological, or chemical agent (NBC); which is only partially true, as a gas mask only protects against respiratory absorption. While most military gas masks are designed to protect against all NBC agents, they can have proof tube filters against (heavier) or only agents against riot and smoke agents (lighter, and often used for training purposes) ; so too there is a light mask only for use in riot control agents and not for the NBC situation.
Although careful training and the availability of gas masks and other protective equipment can negate the effects of accidents from attacks by chemical agents, forces forced to operate in a full-fledged protective device are less efficient at accomplishing tasks, tiring, and possibly psychologically affected by the threat of attacks by these weapons. During the Cold War era, it was seen as inevitable that there would be a constant NBC threat on the battlefield, and thus the troops needed protection where they could remain fully functional; so protective devices, and especially gas masks have evolved to include innovations in terms of improving user convenience, and in compatibility with other equipment (from drinking devices to artificial respiratory tubes, to communication systems etc.). Gas masks have now arrived at 'fourth generation' development.
During the Iran-Iraq War (1980-88), Iraq developed its chemical weapons program with the help of European countries (such as Germany and France), and used them on a large scale against the Iranians and against the Iraqi Kurd. Iran is not ready for a chemical war. In 1984, Iran received gas masks from the Republic of Korea and East Germany, but the Korean mask was not suitable for the faces of non-East Asian people and the filter lasted only 15 minutes, and 5,000 masks purchased from East Germany proved to be not gas masks but spray painting glasses. Until the end of 1986, Iranian diplomats were still traveling in Europe to buy activated charcoal and filter models to produce defense equipment in the country. In April 1988, Iran began production of a domestic gas mask by Iranian Yasa factories.
The world's first filtered charcoal charcoal gas mask was created in 1915 by Russian chemist Nikolay Zelinsky.
In the first gas mask of World War I, it was initially discovered that wood charcoal is a good toxic gas absorber. Around 1918, it was discovered that charcoal made of shells and seeds of various fruits and nuts such as coconut, chestnut, horse-chestnuts, and peach stones performed much better than charcoal wood. These waste materials are collected from the community in the recycling program to assist the war effort.
In schools
Most civilians learn how to use gas masks through the civil defense department, but children receive gas mask education in school practice. The school will implement education and training of gas masks after the outbreak of war. Schools will rigorously enforce compulsory gas masks at all times. Gas masks and air strike attacks are very closely connected and children will be made to wear gas masks in daily activities, including gymnastics. The use of gas masks in the classroom is very difficult for teachers because they are difficult to distinguish one child from another. Gas masks become uniforms of students' uniforms. Other civilians learn to use gas masks through posters, pamphlets and radio lectures, but children learn through cartoons and rhymes such as "coughing and sneezing spread disease".
See also
- Air purifying respirator cartridges and canisters
- GP-5 gas mask
- Gas Mask M2
- M40 Field Guard Mask
- Neurofunk (music genre)
- NBC Settings
- helmet PH
- Outbreak Doctor Clinic
- Respirator
- Test respirator fit
- Small Respirator Box
- Cotton smoke
- Specified Protection Factor
- Respirator tests at work
Note
Bibliography
- Wetherell, Anthony; Mathers, George (2007), "Respiratory Protection", in Marrs, Timothy; Maynard, Robert; Sidell, Frederick, Chemical Warfare Agent: Toxicology and Treatment, New York: Wiley, pp. 157-174, ISBN 978-0470013595
- Mayer-Maguire, Thomas; Baker, Brian (2015), British Military Respirator and Anti-Gas Equipment from Two World Wars , Crowood Ã,
External links
- NBC Gas Mask - 7 Essential Tips thesurvivalcorps.com.
- How to Work Stuff - Science.com Gas Mask
- Inventor Mask History Gas.about.com, About, Inc. updated August 6, 2016
- Respirator Fact Sheet
- CBRN SCBA NIOSH Approved Respirator NIOSH List Approved CBRN SCBA respirator
Source of the article : Wikipedia
0 Comments