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asbestos, common name for any of a variety of silicate minerals within the amphibole and serpentine groups that are fibrous in structure and more or less resistant to acid and fire. Chrysotile asbestos, a form of serpentine that is also known as white asbestos and has curly fibers, is the chief commercial asbestos. Varieties of amphibole asbestos, which has needlelike fibers, are amosite, or brown asbestos, used in insulating materials; crocidolite, or blue asbestos, used for making asbestos-cement products; and tremolite, used in laboratories for filtering chemicals. Asbestos is usually found comprising veins in other rock; in most cases it appears to be the product of metamorphism. The asbestos-producing nations are Russia, Kazakhstan, China, and Brazil. Asbestos is mined both in open quarries and underground.

Since the 1960s, asbestos has been recognized as a potent carcinogen and serious health hazard. Inhalation of airborne asbestos fibers has been established as the cause of asbestosis (thickening and scarring of lung tissue) and as a cause of mesothelioma (a highly lethal tumor of the pleura) as well as of cancers of the lung, intestines, and liver. In 1972, the Occupational Safety and Health Administration began regulating asbestos and strengthening work safety standards. Large class action lawsuits were filed and won against asbestos companies, which had probable prior knowledge of the dangers involved. In 1989, the Environmental Protection Agency imposed a ban on 94% of U.S. asbestos production and imports, to be phased in over a seven year period. Most current asbestos exposure comes from asbestos in older buildings and products such as automobile brakes.


See P. H. Riordon and V. F. Hollister, Geology of Asbestos Deposits (1981); S. S. Chissick and R. Derricott, Asbestos: Properties, Applications and Hazards (1983).

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A noncombustible, flexible mineral fiber that is able to withstand high temperatures; it is fabricated into many forms, either alone or mixed with other ingredients. Once commonly used in many building materials, including insulation, fireproof siding, and resilient flooring. The use of asbestos in some products has been banned by the EPA (Environmental Protection Agency) and the U.S. Consumer Products Safety Commission; manufacturers also have adopted voluntary limitations on its use. When found in older buildings, most commonly in floor tiles, pipe and furnace insulation, or asbestos shingles, the product’s friability is a major determinant in how it must be handled during renovations.
Illustrated Dictionary of Architecture Copyright © 2012, 2002, 1998 by The McGraw-Hill Companies, Inc. All rights reserved
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.



a collective term used to designate a group of fine-fiber minerals of the silicate class that form aggregates made up of extremely fine, flexible fibers. These properties are possessed by minerals of two groups—serpentine and amphibole, known respectively by the names chrysotile asbestos and amphibole asbestos, which differ in atomic structure. Chemically, asbestos minerals are composed of hy-drated silicates of magnesium and iron and partially of calcium and sodium. Most important is chrysotile asbestos, which constitutes 95 percent of the total asbestos in use.

Chrysotile asbestos is a mineral of the serpentine group, Mg6[Si4O10](OH)8; it is a double-layered, sheet-form silicate. One layer consists of silicon oxide tetrahedra, the other of oxide octahedra with magnesium (or sometimes with iron) at the center. In particles it has a greenish-gray color and a silken sheen. Its hardness on the mineralogical scale ranges from 2 to 2.5, and its density is 2,500 kg/m3. The fibers are flexible, possessing a high tensile strength (approximately 3 giganewtons per m2 [300 kilograms-force per mm2]) and a high resistance to fire (the melting point is roughly 1500°C); they are poor conductors of heat and electricity. Fiber length varies from fractions of a millimeter to 50 mm, rarely more, and its thickness is measured in fractions of a micron. Deposits are formed in ultrabasic rocks, rich in magnesium, by the action of hydrothermal solutions connected with younger granites. In the USSR chrysotile asbestos is mined in the Urals (the Bazhenov and Kiembaev deposits), the western part of Kazakhstan (Dzhetygarina), and the Tuva ASSR (Ak-Dovurak). In the northern part of Chita Oblast the Molodezhnyi deposit has been discovered, in which exceptionally long asbestos fibers are encountered. Of great importance are the chrysotile deposits in the serpentine belt of the Eastern and Western Saian mountains, as well as in the Northern Caucasus. Major foreign deposits of chrysotile asbestos have been found in Canada (Quebec Province) and South Africa (Southern Rhodesia and the Republic of South Africa); it is also mined in Czechoslovakia, China, the USA, Italy, France, Finland, Cyprus, Japan, and the Australian Commonwealth. Chrysotile asbestos is suitable for the manufacture of fireproof textile products, heat-insulating products, various fillers for plastics, and asbestos cement.

Amphibole asbestos is represented by several minerals of the amphibole group, such as tremolite, anthophyllite, and crocidolite. Amphibole asbestos is an aggregate of fine, hairlike crystals lying in a parallel or radial formation or without any order at all. The fibers of certain types of amphibole asbestos are brittle. The color and other physical properties depend on its composition. Fiber length ranges up to 5 cm but often is even longer. Deposits of amphibole asbestos are limited to metamorphic rocks; in the USSR they are located in the Urals (Syserf); abroad they are found in Southern Rhodesia and the Republic of South Africa. Amphibole asbestos has a high resistance to acid and seawater and is also a good material for fireproofing and heat-insulating products. It is most widely used in the chemical industry as a filler.


Merenkov, B. Ia. Genezis khrizotil-asbesta. Moscow, 1958.
Mestorozhdeniia khrizotil-asbesta SSSR. Moscow, 1967.


The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.


A general name for the useful, fibrous varieties of a number of rock-forming silicate minerals that are heat-resistant and chemically inert; two varieties exist: amphibole asbestos, the best grade of which approaches the composition Ca2Mg5(OH)2Si8O22(tremolite), and serpentine asbestos, usually chrysotile, Mg3Si2(OH)4O5.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

asbestos, asbestos fiber

Fine, flexible, non-combustible, inorganic fiber obtained from natural hydrous magnesium silicate; can withstand high temperatures without change; a poor heat conductor; is fabricated into many forms either alone or with other ingredients. A recognized health hazard.
McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.


a. any of the fibrous amphibole and serpentine minerals, esp chrysotile and tremolite, that are incombustible and resistant to chemicals. It was formerly widely used in the form of fabric or board as a heat-resistant structural material
b. (as modifier): asbestos matting
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005


Used as a modifier to anything intended to protect one from flames; also in other highly flame-suggestive usages. E.g., asbestos longjohns, asbestos cork award.
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References in periodicals archive ?
To consider whether lung cancer may have been caused by asbestos it is necessary to explore the patient's work history.
With the lapse of time following the last exposure, there is a decreasing number of patients in our data, a decreasing number of asbestos bodies as well as a decreasing asbestos exposure with respect to fiber years (Figure 3a [2]).
Take for example the UK, where asbestos of all forms was completely banned in 1999 and yet diseases such as mesothelioma, lung cancer and asbestosis are still notable causes of deaths in the construction and trade industry.
Although asbestos's use in the United States is heavily restricted and the material is no longer used in construction, the country still allows limited use in products including gaskets, roofing materials and sealants.
Samples were collected from a total of 91 points in 46 separate small-scale preschools at 20 boroughs in Seoul during 9 months, from April to December 2015, surveying airborne asbestos concentrations (Figure 1).
The Beware Asbestos campaign, which was launched on October 9 and will run until March, 2015, aims to encourage safe working practices among those workers most at risk from asbestos - i.e.
Asbestos is believed to pose little risk when encapsulated in housing materials that are in good condition, and is only considered a health hazard when its fibres are present in the air.
There are many sources of asbestos in houses and the most commonly recognised are corrugated cement sheeting, vinyl floor tiles and linoleum sheet flooring and adhesive, loose blown-in loft insulation, soffit boards, textured coatings on ceilings and walls, pipe insulation, insulation boards, gutters and downpipes, flash guards for electrical fuses, acoustic tiles, toilet seats and cisterns, sink baffles and window putty, to name a few.
The Occupational Safety and Health Administration (OSHA) has established permissible exposure limits for asbestos workers.