Anthophyllite asbestos

Veblen, D. R. (1980). Anthophyllite asbestos microstructures, intergrown sheet silicates and mechanism of fiber formation. Amer. Min. 65 1075-1086. 

Measurement of the angle of extinction can be performed as follows Line up the cross hairs (if the eyepiece does not have a cross hair, it is possible to use the lines of a Patterson Globe and Circle Reticle or a porton Reticle) with a natrolite particle or fibers of an anthophyllite asbestos standard which is at extinc... 

Meurman LO, Kiviluoto R, Hakama M. 1974. Mortality and morbidity among the working population of anthophyllite asbestos miners in Finland. Br J Ind Med 31 105-112. 

Varga C, Horvath G, Timbrell V. 1996a. In vivo studies on genotoxicity and cogenotoxicity of ingested UICC anthophyllite asbestos. Cancer Lett 105 181-185. 

Regulatory agencies such as the U.S. Environmental Protection Agency (EPA) and Occupational Safety and Health Administration (OSHA) recognize six asbestos minerals chrysotile, a serpentine mineral and five amphibole minerals, actinolite asbestos, tremolite asbestos, anthophyllite asbestos, crocidolite asbestos, and amosite asbestos. Nonasbestiform amphibole minerals are not included in U.S. health regulations regarding asbestos because there is insufficient evidence that they will produce adverse health effects of the same type and severity produced by chronic exposure to asbestos. 

Tremolite asbestos has only rarely been found in commercially mined deposits. Some tremolite asbestos has been mined in South Africa, India, Maryland, and South Korea, but it has never been a nationally important commercial source of asbestos in the United States. (Ross 1981). The extent of tremolite asbestos mining was small in Powhatan and Pylesville, Maryland, where it occurs with anthophyllite asbestos in ultramafic rocks (Ross 1981). In South Africa, tremolite asbestos was mined in the early twentieth century, but most amphibole asbestos recently mined in South Africa is amosite or crocidolite... 

Results of a survey of asbestos fibers in consumer cosmetic talc powders from Italian and international markets using electron microscopy, electron diffraction, and energy dispersive x-ray analysis showed that asbestos was detected in 6 of 14 talc samples from the European Pharmacopeia (Paoletti et al. 1984). Chrysotile was identified in 3 samples, 2 samples contained tremolite asbestos and anthophyllite asbestos, and 1 sample contained chrysotile and tremolite asbestos. The authors noted that, in all talc powders analyzed, fibrous talc particles frequently were present that were morphologically similar to amphibole asbestos fibers. Counting fibers as particles with aspect ratio >3 1 and width < 3 m, the percentages of particles that were asbestos fibers ranged from <0.03% to 0.13% for 4 samples, and were 18% to 22% for the other 2 samples. Paoletti et al. (1984) noted that the European Pharmacopeia, at that time, had not established analytical quality control of asbestos contamination. 

Talc has been used in the manufacture of crayons for many years. Recently, it was reported in the U.S. press that tremolite asbestos, anthophyllite asbestos, and chrysotile were detected in some crayons at concentrations ranging from 0.03% to 2.86% (CPSC 2000). In response, the Consumer Product Safety Commission (CPSC 2000) examined crayons from several U.S. manufacturers to determine whether asbestos was present. Trace amounts of anthophyllite asbestos were found in some of the crayons. The CPSC (2000) concluded that the risk that children would be exposed to fibers through inhalation or ingestion of talc-containing crayons is extremely low, but recommended that, as a precaution, crayons should not contain these fibers. The manufacturers have agreed to reformulate their crayons using substitute materials (CPSC 2000). 

Synonyms/Trade Names Actinolite, Aotinolite asbestos, Amosite (cummingtonite-grunerite), Anthophyllite, Anthophyllite asbestos, Chrysotile, Crocidolite (Riebeckite), Tremolite, Tremolite asbestos ... 

As found in 29 CFR 1910.1001, the OSHA PEL for asbestos fibers (i.e., actinolite asbestos, amosite, anthophyllite asbestos, chrysotile, crocidolite, and tremolite asbestos) is an 8-hour TWA airborne concentration of 0.1 fiber (longer than 5 micrometers and having a length to diameter ratio of at least 3 to 1) per cubic centimeter of air (0.1 fiber/cm ), as determined by the membrane filter method at approximately 400X magnification with phase contrast illumination. No worker should be exposed in excess of 1 fiber/cm (excursion limit) as averaged over a sampling period of 30 minutes. 

Actinolite Amosite Anthophyllite Asbestos Asbestos, blue, 9 Asbestos, brown Asbestos, white, 9 Blue asbestos Blue asbestos (crocidolite), 9 Brown asbestos (amosite, mysorite), 9 Chrysotile Crocidolite Mysorite Talcum with tremolite and/or actinolite Tremolite White asbestos White asbestos (chrysotile, actinolite, anthophyllite, tremolite), 9... 

Asbestos, blue, brown or white, includes each of the following hydrated mineral silicates chrysotile, crocidolite, amosite, anthophyllite asbestos, tremolite asbestos, actinolite asbestos, and every product containing any of these materials. US 173.216... 

Asbestosincludes chrysotile, amosite, crocidolite, tremolite asbestos, anthophyllite asbestos, actinolite asbestos, and any of these minerals that has been chemically treated and/or altered. For purposes of this standard, asbestos Includes PACM, as defined below. 

Asbestos A term for naturally occurring fibrous miner-ais. Asbestos inciudes chrysotile, cummingtonite-gruner-ite asbestos (amosite), anthophyllite asbestos, tremolite asbestos, crocidoiite, actinolite asbestos and any of these minerals which have been chemically treated or altered. The precise chemicai formulation of each species varies with the location from which it was mined. Nominal compositions are listed ... 

In the 1987 Regulations, asbestos is defined as any of the following minerals crocidolite, amosite, chrysotile, fibrous anthophyllite, fibrous actinolite, fibrous tremolite and any mixture containing any of these. Before carrying out work on any substance suspected of being asbestos, a competent person must be called to advise on its possible... 

Over the past several decades six different silicate minerals have been mined as asbestos and processed for industrial and commercial applications. The most commonly encountered asbestos mineral today is chrysotile. The five other minerals are tremolite, actinolite, anthophyllite, grunerite, and rie-beckite. All five are members of the amphibole group of minerals, and each can occur as chunky, acicular, or equant crystals, as well as in fibrous form. When found as fine fibrous aggregates, in quantities appropriate for mining, they are usually distinguished as a special variety—for example, tremolite-asbestos. 

Two to 3 percent of the world s total asbestos production has been of the crocidolite variety, most of which has come from South Africa. Western Australia was a minor producer of crocidolite between 1944 and 1966. All amosite has been mined in the Transvaal Province of South Africa (2 to 3 percent of the world total). The only significant anthophyllite production came from Finland, where about 350,000 tons were mined between 1918 and 1966. Table 2.6 lists the composition, optical, and diffraction characteristics of the six asbestos minerals. More information on individual mineral species can be found in the references accompanying the sections on serpentine and amphibole types. Discussion of the geology, terminology, and exploitation of the several types of asbestos can be found in Ross (1981). 

Synonyms Asbestos is a generic term applied to a number of hydrated mineral silicates including amosite, chrysotile, tremolite, acti-nolite, anthophyllite, and crocidolite... 

ASBESTOS. The tenn asbestos is a generic designation referring usually to six types of naturally occurring mineral fibers which are or have been commercially exploited, These fibers are extracted from certain varieties of hydrated alkaline silicate minerals comprising two families seipe.ntin.es and amphiboles. The serpentine group contains a single fibrous variety chrysotile five fibrous forms of amphiboles are known anthophyllite, amosite, crocidolite. tremolite, and actinolite... 

The fractional breakdown of the recent world production of the various fiber types shows that the industrial applications of asbestos fibers have now shifted almost exclusively to chrysotile. Two types of amphiboles, commonly designated as amosite and crocidolite are still being used, but their combined production is currently less than 2% of die total world production. The odier three amphibole varieties, anthophyllite, actinolite, and tremolite, have no significant industrial applications presently, This... 

Monoclinic minerals have an inclined angle of extinction. Orthorhombic minerals have parallel extinction. Chrysotile can be monoclinic or orthorhombic depending upon whether it is the ortho or clino variety. The b axis of the clino variety is so close to 90° (93°), (25) that the fibers will appear to have parallel extinction unless this is carefully measured. Anthophyllite, an orthorhombic mineral, has parallel extinction that is, the angle of extinction is zero degrees. All amphibole asbestos minerals except anthophyllite are monoclinic. Although wollastonite is a triclinic mineral, its extinction is parallel, or nearly parallel. The angle of extinction of some asbestos minerals is shown in table I (26, 27). 

Talc fibers may be present in some talcs, especially if the talcs contain anthophyllite or tremolite asbestos and a metamorphosis or transition to talc has taken place. The transition is sometimes incomplete as in talcs from the Gouveneur district of upper New York State. If talc fibers are present, further testing as described below will be necessary. 

If asbestos is present and the sample is not a talc sample, it is most likely to be chrysotile since about 90% or more of the asbestos used in American industry is chrysotile. If the sample is taken from a shipyard, there is a high probability that it will be amosite asbestos. If asbestos is found in a talc sample, it is likely to be anthophyllite or tremolite-actinolite or an asbestos intermediate fiber chrysotile is a possibility, however. If the sample is insulation, expect a variety of fibers. 

R04 RG 600 SERPENTINE SERPENTINE CHRYSOTILE SYLODEX WHITE ASBESTOS WHITE ASBESTOS (chiysotile, actinolite, anthophyllite, ttemolite) (DOT)... 

Asbestos is the name given to a group of six different fibrous minerals (amosite, chrysotile, crocidolite, and the fibrous varieties of tremolite, actinolite, and anthophyllite) that occur naturally in the environment. One of these, namely chrysotile, belongs to the serpentine family of minerals, while all of the others belong to the amphibole family. All forms of asbestos are hazardous, and all can cause cancer, but amphibole forms of asbestos are considered to be somewhat more... 

It is important to recognize that asbestos is not a single substance, but is the generic name for a family of six related poly silicate fibrous minerals of which one (chrysotile) belongs to the serpentine family and five (actinolite, amosite, anthophyllite, crocidolite, and tremolite) belong to the amphibole family. These minerals differ from each other in physical and chemical properties, and each mineral can exist in a wide range of fiber sizes. These differences between fiber type and, more importantly, fiber size (length and diameter) are believed to be important determinants of the health risks posed by asbestos. 

Animal studies also indicate that inhalation exposure to asbestos produces mesotheliomas. Mesotheliomas have been observed in rats exposed to chrysotile, amosite, anthophyllite, crocidolite, or tremolite at concentrations ranging from 350 to 1,600 f/mL for 1-2 years (Davis and Jones 1988 Davis et al. 1985 Wagner et al. 1974, 1980a) and in baboons exposed to either 1,110-1,220 f/mL for 4 years (Goldstein and Coetzee 1990) or 1,100-1,200 17mL for up to 898 days (Webster et al. 1993). Incidences of mesothelioma ranged from 0.7 % to 42% in these studies. 

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