크리스토틸레아베스토

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]:

In case of fire in the surroundings, use appropriate extinguishing media.

Fresh air, rest.

Remove contaminated clothes. Rinse skin with plenty of water or shower.

First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention.

Rinse mouth.

PRECAUTIONS FOR "CARCINOGENS": Storage site should be as close as practical to lab in which carcinogens are to be used, so that only small quantities required for ... expt need to be carried. Carcinogens should be kept in only one section of cupboard, an explosion-proof refrigerator or freezer (depending on chemicophysical properties ...) that bears appropriate label. An inventory ... should be kept, showing quantity of carcinogen & date it was acquired ... Facilities for dispensing ... should be contiguous to storage area. /Chemical Carcinogens/

PRECAUTIONS FOR "CARCINOGENS": A high-efficiency particulate arrestor (HEPA) or charcoal filters can be used to minimize amt of carcinogen in exhausted air ventilated safety cabinets, lab hoods, glove boxes or animal rooms ... Filter housing that is designed so that used filters can be transferred into plastic bag without contaminating maintenance staff is avail commercially. Filters should be placed in plastic bags immediately after removal ... The plastic bag should be sealed immediately ... The sealed bag should be labelled properly ... Waste liquids ... should be placed or collected in proper containers for disposal. The lid should be secured & the bottles properly labelled. Once filled, bottles should be placed in plastic bag, so that outer surface ... is not contaminated ... The plastic bag should also be sealed & labelled. ... Broken glassware ... should be decontaminated by solvent extraction, by chemical destruction, or in specially designed incinerators. /Chemical Carcinogens/

Chrysotile asbestos fibers in lab solutions were degraded by chemical treatment.

SRP: Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in air, soil or water; effects on animal, aquatic and plant life; and conformance with environmental and public health regulations. If it is possible or reasonable use an alternative chemical product with less inherent propensity for occupational harm/injury/toxicity or environmental contamination.

SRP: Wastewater from contaminant suppression, cleaning of protective clothing/equipment, or contaminated sites should be contained and evaluated for subject chemical or decomposition product concentrations. Concentrations shall be lower than applicable environmental discharge or disposal criteria. Alternatively, pretreatment and/or discharge to a permitted wastewater treatment facility is acceptable only after review by the governing authority and assurance that "pass through" violations will not occur. Due consideration shall be given to remediation worker exposure (inhalation, dermal and ingestion) as well as fate during treatment, transfer and disposal. If it is not practicable to manage the chemical in this fashion, it must be evaluated in accordance with EPA 40 CFR Part 261, specifically Subpart B, in order to determine the appropriate local, state and federal requirements for disposal.

PRECAUTIONS FOR "CARCINOGENS": There is no universal method of disposal that has been proved satisfactory for all carcinogenic compounds & specific methods of chem destruction ... published have not been tested on all kinds of carcinogen-containing waste. ... summary of avail methods & recommendations ... /given/ must be treated as guide only. /Chemical Carcinogens/

PRECAUTIONS FOR "CARCINOGENS": ... Incineration may be only feasible method for disposal of contaminated laboratory waste from biological expt. However, not all incinerators are suitable for this purpose. The most efficient type ... is probably the gas-fired type, in which a first-stage combustion with a less than stoichiometric air:fuel ratio is followed by a second stage with excess air. Some ... are designed to accept ... aqueous & organic-solvent solutions, otherwise it is necessary ... to absorb soln onto suitable combustible material, such as sawdust. Alternatively, chem destruction may be used, esp when small quantities ... are to be destroyed in laboratory. /Chemical Carcinogens/

For more Disposal Methods (Complete) data for Chrysotile asbestos (7 total), please visit the HSDB record page.

Evacuate danger area! Consult an expert! Personal protection: complete protective clothing including self-contained breathing apparatus. Vacuum spilled material with specialist equipment. Then store and dispose of according to local regulations.

PRECAUTIONS FOR "CARCINOGENS": Smoking, drinking, eating, storage of food or of food & beverage containers or utensils, & the application of cosmetics should be prohibited in any laboratory. All personnel should remove gloves, if worn, after completion of procedures in which carcinogens have been used. They should ... wash ... hands, preferably using dispensers of liq detergent, & rinse ... thoroughly. Consideration should be given to appropriate methods for cleaning the skin, depending on nature of the contaminant. No standard procedure can be recommended, but the use of organic solvents should be avoided. Safety pipettes should be used for all pipetting. /Chemical Carcinogens/

PRECAUTIONS FOR "CARCINOGENS": In animal laboratory, personnel should remove their outdoor clothes & wear protective suits (preferably disposable, one-piece & close-fitting at ankles & wrists), gloves, hair covering & overshoes. ... Clothing should be changed daily but ... discarded immediately if obvious contamination occurs ... /also,/ workers should shower immediately. In chemical laboratory, gloves & gowns should always be worn ... however, gloves should not be assumed to provide full protection. Carefully fitted masks or respirators may be necessary when working with particulates or gases, & disposable plastic aprons might provide addnl protection. If gowns are of distinctive color, this is a reminder that they should not be worn outside of lab. /Chemical Carcinogens/

PRECAUTIONS FOR "CARCINOGENS": ... Operations connected with synth & purification ... should be carried out under well-ventilated hood. Analytical procedures ... should be carried out with care & vapors evolved during ... procedures should be removed. ... Expert advice should be obtained before existing fume cupboards are used ... & when new fume cupboards are installed. It is desirable that there be means for decreasing the rate of air extraction, so that carcinogenic powders can be handled without ... powder being blown around the hood. Glove boxes should be kept under negative air pressure. Air changes should be adequate, so that concn of vapors of volatile carcinogens will not occur. /Chemical Carcinogens/

PRECAUTIONS FOR "CARCINOGENS": Vertical laminar-flow biological safety cabinets may be used for containment of in vitro procedures ... provided that the exhaust air flow is sufficient to provide an inward air flow at the face opening of the cabinet, & contaminated air plenums that are under positive pressure are leak-tight. Horizontal laminar-flow hoods or safety cabinets, where filtered air is blown across the working area towards the operator, should never be used ... Each cabinet or fume cupboard to be used ... should be tested before work is begun (eg, with fume bomb) & label fixed to it, giving date of test & avg air-flow measured. This test should be repeated periodically & after any structural changes. /Chemical Carcinogens/

For more Preventive Measures (Complete) data for Chrysotile asbestos (19 total), please visit the HSDB record page.

In vitro studies have shown that the effects of asbestos can be diminished by compounds that reduce the levels of reactive oxygen species, such as free radical scavengers (ascorbic acid, bemitil, mannitol, salicylate, 5,5'-dimetyl-l-proline N-oxide, rutin, vitamin E, vitamin A) and enzymes that catalyze the decomposition of reactive oxygen species (catalase, superoxide dismutase). Patients should quit smoking, perform bronchial drainage and can use chest physical therapy techniques to further aid in removing secretions. Shortness of breath is treated with bronchodilators, inhaled or oral medications that open up the bronchial tubes and allow the passage of air. In more severe asbestosis cases, supplemental oxygen may be required. Productive cough is treated with humidifiers and chest percussion. Asbestosis can be treated, but not cured. (L222, L227)

In vitro studies have shown that the effects of asbestos can be diminished by compounds that reduce the levels of reactive oxygen species, such as free radical scavengers (ascorbic acid, bemitil, mannitol, salicylate, 5,5'-dimetyl-l-proline N-oxide, rutin, vitamin E, vitamin A) and enzymes that catalyze the decomposition of reactive oxygen species (catalase, superoxide dismutase). Patients should quit smoking, perform bronchial drainage and can use chest physical therapy techniques to further aid in removing secretions. Shortness of breath is treated with bronchodilators, inhaled or oral medications that open up the bronchial tubes and allow the passage of air. In more severe asbestosis cases, supplemental oxygen may be required. Productive cough is treated with humidifiers and chest percussion. Asbestosis can be treated, but not cured. (L222, L227)

...Among 31 hamsters receiving total dose of 4.5 mg (benzo(a)pyrene) plus 12 mg chrysotile /by intracheal injection/ over period of 12 wk, 7 developed pulmonary adenomas, 7 pulmonary carcinomas, 9 tracheal papillomas and 1 laryngeal papilloma. No lung tumors were observed in 17 hamsters receiving chrysotile alone, and only 1 pulmonary carcinoma but 9 tracheobronchial papillomas were found among 38 hamsters receiving (benzo(a)pyrene) alone.

Exposure of rat liver epithelial cells to chrysotile alone did not increase the mutant incidence whereas benzo(a)pyrene was mutagenic. Simultaneous exposure of the cells to chrysotile and benzo(a)pyrene resulted in an enhanced mutant recovery compared to exposure to either of these substances alone.

The combined carcinogenic activity of intratracheally inoculated Canadian chrysotile asbestos dust and orally or sc administered n-nitrosodiethylamine was studied in long term experiments in Syrian Golden hamsters. In animals treated with asbestos only, no lung tumors developed, and single tracheal or laryngeal papillomas were found in only a very few cases. In animals treated with chrysotile asbestos and n-nitrosodiethylamine, a synergistic effect which increased the incidence of lung tumors was observed.

With regard to mesotheliomas, 1 study suggested a particularly high risk of combined exposure to chrysotile and amphiboles (risk ratio, 61), thus almost multiplying the risk ratios (6 and 12, respectively) of exposures to chrysotile and to amphibole alone.

For more Interactions (Complete) data for Chrysotile asbestos (12 total), please visit the HSDB record page.

Infected people develop a slow buildup of scar-like tissue in the lungs and in the membrane that surrounds the lungs, so breathing becomes difficult. Blood flow to the lung may also be decreased, and this causes the heart to enlarge. This disease is called asbestosis. Infected people have increased chances of getting two principal types of cancer: cancer of the lung tissue itself and mesothelioma, a cancer of the thin membrane that surrounds the lung and other internal organs. The cellular immune system of the patient can be depressed. Also, deletions of chromosome segments have been noted in human mesothelioma cells or cell lines. (L222)

Infected people develop a slow buildup of scar-like tissue in the lungs and in the membrane that surrounds the lungs, so breathing becomes difficult. Blood flow to the lung may also be decreased, and this causes the heart to enlarge. This disease is called asbestosis. Infected people have increased chances of getting two principal types of cancer: cancer of the lung tissue itself and mesothelioma, a cancer of the thin membrane that surrounds the lung and other internal organs. The cellular immune system of the patient can be depressed. Also, deletions of chromosome segments have been noted in human mesothelioma cells or cell lines. (L222)

AQUATIC FATE: ... In a study of the zeta potentials of natural and synthetic chrysotiles ... a wide variety of zeta potentials /were found/. Strongly positive values were found in samples containing an excess of magnesium in the form of brucite (Mg(OH)2). Synthetic chrysotile and natural samples containing little or no brucite, gave moderately positive zeta potentials over the pH range of 3-11. Feebly positive or weakly negative zeta potentials were found in chyrsotiles which had undergone weathering (due to natural leaching of the brucite layer). Since the pH at the ambient concentration of Mg2+ ions near the surface are the main controlling factors of the chrysotile zeta potential, and since chrysotile's brucite layer is susceptible to leaching in aqueous solution, the zeta potential of chrysotile is a constantly changing value. These results explain the temporary colloidal stability of dilute suspensions of chrysotile in the environmental media and the mutual coagulation of chrysotile and amphibole asbestos slurries.

AQUATIC FATE: ... Due to the positive zeta potential of chrysotile in environmental media, low viscosity suspensions could be prepared by means of the inherent charge of the chrysotile surfaces. This charge however, is so small in pure chrysotile that dispension was obtained only with short fibers and low fiber concentrations (1%). By increasing the concentration of certain metallic salts ... it was found that low viscosity suspensions could be prepared under almost any environmental condition. These observations suggest that the presence of trace metals will produce a suspension of chrysotile asbestos in water which will persist until sufficient magnesium has leached from the chrysotile structure to degrade the suspension. ... It is probable that under certain conditions asbestos will persist in the water column until its concentration becomes high enough to destroy the suspension or until leaching of the brucite layer decays the zeta potential to a point where it will become negative.

The substance can be absorbed into the body by inhalation.

Inhalation (L222) ; injection (L222)

Inhalation (L222) ; injection (L222)

IDENTIFICATION AND USE: Chrysotile asbestos forms monoclinic crystals, which are usually white to grayish green, but may have tan coloration. Chrysotile, the most abundant form of asbestos in industrial applications, occurs naturally in fiber bundle lengths ranging from several millimeters to over 10 cm. Chrysotile was the predominant fiber type in use in buildings. Other uses include paper products, paint and caulking, textiles and plastics. HUMAN STUDIES: Most airborne chrysotile fibers are considered respirable because their fiber diameters are less than 3 um. Analyses of human lungs of workers exposed to chrysotile asbestos indicate much greater retention of tremolite, an amphibole asbestos commonly associated with commercial chrysotile in small proportions, than of chrysotile. In humans commercial grades of chrysotile have been associated with an increased risk of lung cancer in epidemiological studies of exposed workers. Mesothelioma and digestive-tract cancer were observed in workers occupationally exposed to chrysotile. An excess of laryngeal cancer was reported in studies of chrysotile miners. Cytogenetic study of workers in the chrysotile asbestos industry demonstrated that chromosome type aberrations were presented by paired fragments and centromere rupture, those of chromatide type - by deletions, single fragments and chromatide ruptures. ANIMAL STUDIES: In laboratory rats, chrysotile fibers are deposited primarily at the alveolar duct and bifurcations. In the nasopharyngeal and tracheobronchial regions, chrysotile fibers are cleared via mucociliary clearance. At the alveolar duct bifurcations the fibers are taken up by epithelial cells. Fiber length is an important determinant of alveolar clearance of chrysotile fibers. Short fibers (less than 5 um long) are cleared more rapidly than long fibers. Chrysotile is more rapidly cleared from the lung than are ampohiboles including crocidolite and amosite. Experimental samples of chrysotile fibers have been shown in long term inhalation studies to cause fibrogenic and carcinogenic effects in laboratory rats. These effects include interstitial fibrosis and cancer of the lung and pleura. Fibrogenic and carcinogenic effects have also been found in long term studies in rats using other modes of administration (intratracheal instillation and intrapleural or intraperitoneal injection.) When filter material containing chrysotile was added to the diet of rats, the overall incidence of malignant tumors (including kidney, lung, and liver tumors) was increased. Oral administration of chrysotile did not cause tumors in hamsters. Dietary administration of chrysotile asbestos fibers of short or intermediate lengths did not cause tumors in female rats, but dietary exposure to the intermediate-length fibers resulted in a low incidence of benign adenomatous polyps of the large intestine in male rats. Placental transmission of chrysotile asbestos fibers from mother to fetus with reliable increased incidence of neoplasma in first generation was demonstrated in rats. Chrysotile demonstrated fetotoxicity and teratogenicity in mice. Chinese hamster cells exposed to 0.01 ng/mL chrysotile had a significantly increased number of chromosome abnormalities. Chrysotile induced unscheduled DNA synthesis in rat hepatocytes. Chrysotile did not induce micronuclei in bone-marrow cells of mice or chromosomal aberrations in bone-marrow cells of rhesus monkeys treated in vivo. Based on the broad surface area of asbestos fibers and their ability to enter the cytoplasm and nuclei of cells, it was hypothesized that proteins that adsorb onto the fiber surface play a role in the cytotoxicity and carcinogenesis of asbestos fibers. Chrysotile directly interact with chromatin structure through different mechanisms. Furthermore, RNA-binding proteins preferably interacted with chrysotile, suggesting that chrysotile may also interfere with transcription and translation. ECOTOXICITY STUDIES: L. gibba plants were exposed to four concentrations (0.5, 1.0, 2.0, and 5.0 ug/mL) of chrysotile asbestos under laboratory conditions. Chrysotile exposure caused a decrease in total and reduced glutathione and an enhancement in the oxidized glutathione as well as the reduced/oxidized glutathione ratio. An increase in ascorbate pool size, and reduced as well as oxidized ascorbate was found to be accompanied by a decrease in the ratio of reduced/oxidized ascorbate.

The majority (approximately 95%) of water consumers in the United States are exposed to asbestos fiber concentrations of less than 10 fibers/L. In a few areas people are exposed to concentrations between 1 and 10 million fibers/L with intermittent exposures over 100 million fibers/L. There is at least one area where continuous exposure is over 100 million fibers/L. The mass concentrations of chrysotile asbestos in the water of cities with less than 1X10+6 fibers/L are likely to be less than 0.01 ug/L, corresponding to a daily intake of less than 0.02 ug. However, in areas with significant contamination, whether from natural sources, man's activities, or erosion from A/C pipes, the intake of asbestos from water can exceed 2 ug/day. There is at least one area where continuous exposure is over 100 million fibers/L. Everett, Washington, with concentrations of chrysotile above 1X10+7 fibers/L; Seattle, with from 1X10+6 to 1X10+7 fibers/L; and San Francisco, with chrysotile concentrations about 1X10+7 fibers/L in some systems

/AQUATIC SPECIES/ The effects of chrysotile asbestos on siphoning activity, shell and tissue growth, fiber uptake, and gill ultrastructure in adult Asiatic clams (Corbicula sp.) and on larval release and mortality patterns from reproductively active adults were evaluated in 96-hr to 30-day experiments at 0-108 fibers/L. Adult siphoning activity was significantly (a = 0.05) depressed in 96-hr asbestos exposures when no food was offered or after 30 days when food was available. Shell growth was significantly inhibited in accordance with reduced siphoning. Corbicula exposed to 108 fibers/L accumulated 69.1 fibers/mg dry weight if food was offered. Fiber uptake was not observed at lower concentrations in 96-hr or 30-day tests. Adult clams exposed to 108 fibers/L for 30 days accumulated 147.3 and 903.7 fibers/mg in gill and viscera, respectively. Gill tissue was significantly altered at 108 fibers/L and fibers were observed in gill locules and in ctenidial tissue. Fiber dimension analysis suggested that small, thin fibers were preferentially accumulated by both gill and visceral tissues. Significant increases in mortality of larvae exposed to asbestos and decreases in larvae released per milligram of adult dry weight were observed in reproductive adults exposed to asbestos at 104-108 fibers/L. Corbicula is an efficient accumulator of chrysotile asbestos and may be considered for use as an indicator of asbestos contamination.

/AQUATIC SPECIES/ The effects of chrysotile asbestos on larval coho salmon (Oncorhynchus kisutch) and juvenile green sunfish (Lepomis cyanellus) were investigated at levels approximating those reported in the Great Lakes basin (106 fibers/liter). Behavioral stress effects, such as loss of rheotaxic position and balance, were observed in salmon exposed at 3.0 X 10+6 fibers/liter and in sunfish exposed at 1.5 and 3.0 X 10+6 fibers/liter. Coho larvae at 1.5 X 10+6 fibers/liter were significantly more susceptible to an anesthetic stress test, becoming ataxic and losing equilibrium faster than control cohorts (P < 0.001). Two of 106 larvae exposed at 3.0 X 10+6 fibers/liter developed tumorous swellings and three additional fish developed coelomic distentions. Cytological examination of ventral epidermal tissue revealed cellular histolysis, and evidence by transmission electron microscopy confirmed the presence of asbestos in the salmon larvae. Distortion of the lateral line region in asbestos-treated coho salmon was linked to behavioral and orientational aberrations. Differential mortality was not observed between control and treated groups of either test species.

/AQUATIC SPECIES/ Chrysotile asbestos is a fibrous contaminant of water supplies in the United States, Canada and abroad. Evaluations of the effects of chrysotile were made on all life stages of the cyprinodontid fish, the Japanese Medaka (Oryzias latipes). These included: egg hatchability and survival; larval to juvenile growth, survival, histopathology and asbestos bioaccumulation; and adult reproduction and asbestos bioaccumulation. Asbestos did not substantially impair the egg stage at concentrations of less than 108 fibers/l. Larval and juvenile fish were the most sensitive stages with significant growth reductions occurring at 10+6-10+8 fibers/L and 100% mortality at 10+10 fibers/L in 56 days of exposure. At 10+10 fibers/L, direct evidence (transmission election microscopy of selected tissues) of chrysotile accumulation was present with concomitant epidermal lesions. A small percentage (5% of those originally exposed) of fish at 10+10 fibers/L developed ventral non-invasive epidermal hyperplastic plaques. Reproduction tests resulted in 33% greater spawning frequency in control populations (compared to 10+4 and 10+8 fibers/L) and 25% more viable eggs. It is concluded that chrysotile may represent a significant environmental hazard, especially to young fish, and that asbestos should receive greater attention than it has historically received.

Cough.

Symptoms of asbestos exposure include shortness of breath, often accompanied by a cough. (L222)

Symptoms of asbestos exposure include shortness of breath, often accompanied by a cough. (L222)

The following link will take the user to the National Toxicology Program (NTP) Test Status of Agents Search page, which tabulates the results and current status of tests such as "Short-Term Toxicity Studies", "Long-term Carcinogenicity Studies", "Developmental Studies", "Genetic Toxicology Studies", etc., performed with this chemical. Testing status for chrysotile asbestos is available.[Available from, as of March 27, 2018: https://ntpsearch.niehs.nih.gov/?e=True&ContentType=Testing+Status]

... The leaching of asbestos in distilled water and at body temperature (37 °C) /was determined/. ... although ... chemical equilibrium /could not be reached/ after 2 months of leaching, a significant amount of the chrysotile had dissolved (1,000 umol of Mg/g asbestos had been leached). ... ... The effect of milling (done to produce industrial useful fibers) on the chemical structure of asbestos /was determined/. The milling altered the crystallinity of the chrysotile which appeared to include shifts in interlayer bonding between the magnesium & silica sheets & changes in hydroxyl configuration. The changes would theoretically increase the leachability of chrysotile in water & might replicate the effect that transport in the aquatic environment would have on the individual asbestos fiber.

Chrysotile asbestos is a naturally formed serpentine mineral fiber(1).

... The origin of asbestos has been the subject of extensive geological research. Serpentine asbestos such as chrysotile occurs under widely differing geological conditions from the amphiboles. Similary, the modes of occurrence or the manner in which the fibers are physically imbedded in the host rock also differ widely. The current opinion is that chrysotile fiber resulted from two separate metamorphic reactions in ultrabasic rocks of igneous origin. The initial hydrothermal reaction altered the olivines and pryroxenes to serpentine. At a subsequent point the serpentine was redissolved and the mineral rich solutions flowed into cracks and crevices in the host rock where chrysotile fiber was reprecipitated. In this reprecipitation process, asbestos fiber was usually deposited in a cross-vein mode of occurrence; i.e., the fiber is arranged perpendicular to the wall rock. In some cases, chrysotile was either deposited or affected by earth movements such that the fibers lie principally parallel to the wall rock. This mode of occurrence is referred to as slip fiber. The 3rd and unusual mode of occurrence of chrysotile is referred to as a massive or agglomerated form wherein the fibers have been deposited as platelets having no specific fiber orientation. This unique formation has been found and commercially mined in the New Idria serpentine deposits of California and at Stragari, Yugoslavia. In these cases the asbestos content of the ore is abnormally high, but the fiber length is very short as compared to commercially useful cross-vein.

Pursuant to section 8(d) of TSCA, EPA promulgated a model Health and Safety Data Reporting Rule. The section 8(d) model rule requires manufacturers, importers, and processors of listed chemical substances and mixtures to submit to EPA copies and lists of unpublished health and safety studies. Chrysotile asbestos is included on this list. Effective date: 10/4/82; Sunset date: 10/4/92.

Persons in charge of vessels or facilities are required to notify the National Response Center (NRC) immediately, when there is a release of this designated hazardous substance, in an amount equal to or greater than its reportable quantity of 1lb or 0.454 kg. The toll free number of the NRC is (800) 424-8802. The rule for determining when notification is required is stated in 40 CFR 302.4 (section IV. D.3.b). /The RQ for asbestos is limited to friable forms only./

The combination of asbestos fibers with various types of natural or synthetic resins led to the development of a variety of products and applications. Among those, the incorporation of asbestos fibers (mainly chrysotile) into rubber matrices yields materials that were widely used for the fabrication of packings and gaskets. Complex formulations, comprising short asbestos fibers (usually chrysotile), resins, and other fillers and modifiers, were developed as friction materials for brake linings and pads. Asbestos fibers also found broad application as reinforcing agents in coatings, sealings, and adhesive formulations. Of these applications, brake linings and pads, gaskets, and roof coatings remain the bulk of the consumption.

Loose asbestos fibers, or formulations containing asbestos fibers for spray coatings, were widely used in the building industry for fire protection and heat or sound insulation during and after World War II. Such applications used mainly chrysotile or amosite ... This practice was discontinued in the 1970s because of health concerns.

In different types of packings, woven brake linings to clutch facings, and electric insulation.

Chrysotile fibers were frequently used as a reinforcing agent in cement, paper and plastic products.

For more Uses (Complete) data for Chrysotile asbestos (7 total), please visit the HSDB record page.

Asbestos are used in building materials (roofing shingles, ceiling and floor tiles, paper products, and asbestos cement products), friction products (automobile clutch, brake, and transmission parts), heat-resistant fabrics, packaging, gaskets, and coatings. Some vermiculite or talc products may contain asbestos. Exposure most likely by breathing air containing asbestos fibers or by drinking asbestos fibers that are present in water. (L222)

Tremolite is an amphibole that is found as a contaminant in chrysotile and talc deposits.

The impurities which are present in chrysotile may be part of the crystal structure or due to associated minerals. The most common impurity is iron, and the next is aluminum; other impurities associated with chrysotile in lesser amount are calcium, chromium, nickel, manganese, sodium and potassium.

... The processes that yield the chrysotile fiber formations usually involve the crystallization of various other minerals. These mineral contaminants comprise brucite; magnetite; calcite; dolomite; chlorites; and talc. Other iron-containing minerals also may be found in chrysotile (eg, pyroaurite, brugnatellite, and pyroxenes).

... Nine Canadian chrysotile samples /were analyzed/ for trace metals ... 2-14 ug/g beryllium, 3-10 ug/g cadmium, 202-771 ug/g chromium, 36-78 ug/g cobalt, 9-26 ug/g copper, 325-1065 ug/g manganese, 299-1187 ug/g nickel, and 35-71 ug/g thallium /were found/ in the asbestos samples. Similar results were found in ... a study of trace elements in the Reserve Mining Company's taconite dumpings in Lake Superior.

For more Impurities (Complete) data for Chrysotile asbestos (6 total), please visit the HSDB record page.

(1972) 4.5X10+10 G

(1975) 3.2X10+10 G

(1972) 5.9X10+11 G

(1975) 4.6X10+11 G

1.95X10+11 g

(1972) 1.1X10+11 G (ESTIMATED)

(1975) 8.5X10+10 G (ESTIMATED)

In 1975, the total consumption of asbestos in the USA was 550,900 metric tons.

ASBESTOS-CEMENT PIPE & SHEET, 30%; FLOORING PRODUCTS, 23%; FRICTION PRODUCTS, 14%; ROOFING PRODUCTS, 9%; COATING & COMPOUNDS, 5%; PAPER, 4%; PACKING & GASKETS, 4%; ELECTRICAL & THERMAL INSULATION PRODUCTS, 3%; TEXTILES, 1%; PLASTICS, 1%; OTHER, 5% (1977) /Asbestos/

Chrysotile fiber accounts for a very high proportion of total asbestos use (94% in 1974).

Wet milling operations, in which the asbestos is dispersed in water and not dried until after the final separation process is completed, offer advantages in dust control and the separation of mineral contaminants from the fiber product. Wet process technology, however, is currently used in only a few small-scale milling operations.

In dry milling operations, which are currently the most widely used, the ore is first crushed to a nominal size and then dried. Fiber extraction then begins through a series of crushing operations, each followed by a vacuum aspiration of the ore running on a vibrating screen. On the latter, the fibers released from the ore tend to move to the surface and, because of their aerodynamic properties, can be readily collected into a vacuum system. The fibers recovered from consecutive vibrating screens are brought to cyclone separators, and the air is filtered to remove the finer suspended fibers. Generally, the consecutive crushing-aspiration steps liberate fibers that are increasingly shorter. Longer fibers in wide veins are easier to release and thus are recovered in the early phases of the milling operation. In this way, a primary classification, or grading, of the fibers can be achieved. Various secondary processing systems may be used to separate the fiber aggregates and to remove nonfi- brous mineral dust. Fiber extraction and classification operations are usually carried out under negative pressure to minimize airborne dust in the working environment.

The chemical compositions vary somewhat, depending on deposit location, from the idealized composition of magnesium disilicon pentadioxide tetrahydoxide. Chemical analyses of chrysotile range approximately as follows: Calcium oxide, 37-44%; Magnesium oxide, 39-44%; Ferrous oxide, 0 to 6.0%; Ferric oxide, 0.1-5.0%; Aluminum oxide, 0.2-1.5%; CaO, trace to 5.0%; water , 12.0-15.0%. Variations in chemical analyses may be due to either associated mineral impurities or to isomorphic substitutions in the crystal lattice.

Asbestos is a commercial term that covers a number of naturally occurring silicate minerals whose crystals grow in the fibrous habit. Although there are four types of natural asbestiform mineral fibers that have been in industrial use, only three have been used in the United States: amosite, chrysotile, and crocidolite. The fourth, anthophyllite, is mined and used in Finland. Of the three asbestos types that have been used in North America, Canadian chrysotile, has formed 95% of all natural fibers used, with amosite and crocidolite (both imported from South Africa) constituting the other 5%. Chrysotile is classified as a serpentine mineral, whereas the other three asbestos types are amphiboles. Tremolite is an amphibole that is found as a comtaminant in chrysotile and talc deposits.

Asbestos minerals are divided into two major groups: Serpentine asbestos and amphibole asbestos. Serpentine asbestos includes the mineral chrysotile, which has long, curly fibers that can be woven. Chrysotile asbestos is the form that has been used most widely in commercial applications. Amphibole asbestos includes the minerals actinolite, tremolite, anthophyllite, crocidolite, and amosite. Amphibole asbestos has straight, needle-like fibers that are more brittle than those of serpentine asbestos and are more limited in their ability to be fabricated.

In 2017, all of the asbestos minerals imported into and used within the United States consisted of chrysotile and were shipped from Brazil.

Canadian chrysotile crudes are classified as follows: crude #1: 1.9 cm staple & longer; crude #2: 0.95 cm to 1.9 cm staple; crude run of mine: unsorted crudes. Milled Canadian fibers sold from Quebec are classified by a dry screen technique known as the Quebec Standard Asbestos Test. This test method grades fibers roughly by fiber or staple length. Minimum test values are guaranteed for each grade & a numerical classification system has been estabilished for fibers ranging from Group 3, the longest grade, to Group 7, the shortest grade. Chrysotile fibers produced outside Quebec are graded or controlled by screening test methods differing from the Quebec Screen Test; however, these basically identify grade by staple length.

For more General Manufacturing Information (Complete) data for Chrysotile asbestos (7 total), please visit the HSDB record page.