The uses of chrysotile

Our plain-English summary of The uses of chrysotile, by B.J. Pigg (The Annals of Occupational Hygiene, 1994).

The study

• Author: B.J. Pigg
• Journal: The Annals of Occupational Hygiene
• Published: 1994;38(4):453-8, 408
• Cited by: 13 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Chrysotile asbestos was used in thousands of commercial products in the past. However, current usage is confined to four principal product categories. These are: asbestos cement; friction materials; roof coatings and cements; and gaskets. Current products, different from several friable products formerly in major use and discontinued some 20 years ago, in the majority of countries, have the asbestos locked-in or encapsulated within another matrix. With modern control measures, exposures are minimized throughout the product life cycle. Approximately 85% of chrysotile used worldwide is for production of asbestos-cement products (pipes and sheets). In 1992, approximately 28 million tones of asbestos-cement products were produced in approximately 100 countries.

In plain English

This 1993 workshop paper was a review of how chrysotile asbestos was used. It did not study workers or disease. The author reported that chrysotile made up 98.5% of U.S. asbestos consumption in 1992. World asbestos production had fallen from nearly 5 million tons in 1973 to 3.1 million tons. Asbestos-cement products accounted for some 85% of all use. Each year 27 to 30 million tons were made in more than 100 countries. They contained 10 to 15% asbestos, mostly chrysotile, with limited crocidolite in large pipes. Other significant uses were friction products, roof coatings and cements, and asbestos paper, and demand remained strong for high-temperature gaskets. The author stated that friable products such as insulation had largely been discontinued and that the vast majority of current products held chrysotile locked in another material. According to the author, friction and asbestos-cement products locked fibres into resin or cement and did not release them except when vigorously manipulated. The author concluded that asbestos use today can be controlled to exposure levels substantially below those associated with disease in the past. Only the United States collected product data by country centrally, the author noted.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Review of chrysotile uses, production and exposure potential, presented as a workshop paper; no original study of people
• Who was studied: No people were studied. The paper covered asbestos production and use: world production by country for 1988 to 1992, U.S. demand for 1977, 1984 and 1991, and Canadian shipments by fibre grade in 1991
• Exposure: Chrysotile asbestos, mainly in asbestos-cement sheets, slates and pipes, friction products (brake linings, clutch facings), roof coatings and cements, asbestos paper and gaskets. Past friable uses such as insulation and textiles were also covered, and amphiboles (crocidolite, amosite) were discussed briefly
• Main results:
  • Chrysotile made up 98.5% of U.S. asbestos consumption in 1992
  • World asbestos production rose 50% between 1964 and 1973, reaching nearly 5 million tons, then generally declined to 3.1 million tons
  • South African production of crocidolite and amosite fell from 280000 tons a year in the late 1970s to 55000 tons in 1992, and the last amosite mine closed in late 1992
  • Asbestos cement accounted for some 85% of all asbestos use worldwide
  • Each year 27 to 30 million tons of asbestos-cement products were made in more than 100 countries. They contained 10 to 15% asbestos, mostly chrysotile, with limited crocidolite used in large pipes
  • Apart from asbestos cement, significant amounts of chrysotile went into only a few uses: friction products, roof coatings and cements, and asbestos paper. Demand remained strong for high-temperature gaskets
  • U.S. demand across major asbestos uses declined between 1977 and 1991. Table 2 totals were 672 in 1977, 226 in 1984 and 34 in 1991
  • Friable asbestos products had largely been discontinued, and the vast majority of current products held chrysotile locked in or encapsulated within another material
  • Friction and asbestos-cement products locked fibres into resin or cement and did not release them except when vigorously manipulated
  • In 1991 most Canadian chrysotile shipments were intermediate grades: 160 000, 168 000 and 232 000 tons for Grades 4, 5 and 6. Shipments were 8000 tons for Grades 1 to 3 and 120000 tons for Grade 7
  • The author stated that studies by others had found exposures of custodial, maintenance and other building workers well below national permissible exposure limits. These studies were not described
  • The U.S. EPA's 1989 ban on nearly all asbestos uses was overturned in 1991 by the U.S. Court of Appeals for the Fifth Circuit
• The authors' conclusion: The author concluded that asbestos use today can be controlled to exposure levels substantially below those associated with disease in the past
• Limitations the authors state:
  • Outside the United States, no central data on asbestos product production by country existed, so it was difficult to break down product types against total asbestos consumption

Topics

The National Library of Medicine indexes this study under subjects our site covers: Chrysotile.

Medical terms in this study, explained in our Lexicon: Chrysotile, Asbestos-Cement, Gasket, Friable.

Related studies

• How conflicted authors undermine the World Health Organization (WHO) campaign to stop all use of asbestos: spotlight on studies showing that chrysotile is carcinogenic and facilitates other non-cancer asbestos-related diseases — X. Baur, C.L. Soskolne, et al. (2015)
• Evaluation of the deposition, translocation and pathological response of brake dust with and without added chrysotile in comparison to crocidolite asbestos following short-term inhalation: interim results — D.M. Bernstein, R. Rogers, et al. (2014)
• Environmental contamination of chrysotile asbestos and its toxic effects on growth and physiological and biochemical parameters of Lemna gibba — A.K. Trivedi, I. Ahmad, et al. (2004)
• Mesotheliomas and chrysotile — P. Elmes (1994)
• Assessing specific causation of mesothelioma following exposure to chrysotile asbestos-containing brake dust — M.D. Freeman, S.S. Kohles (2012)
• Human evidence: lung cancer mortality risk from chrysotile exposure — J.M. Hughes (1994)

Browse more research in The Annals of Occupational Hygiene, or return to medical research.