Types and Health Hazards of Fibrous Materials Used as Asbestos Substitutes

Our plain-English summary of Types and Health Hazards of Fibrous Materials Used as Asbestos Substitutes, by S.H. Park (Safety and Health at Work, 2018).

The study

• Author: S.H. Park
• Journal: Safety and Health at Work
• Published: 2018;9(3):360-364
• Cited by: 11 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Asbestos has been banned in many countries but many countries, including developing countries, are still using asbestos or materials containing asbestos. Substitute materials have been studied and developed over a long period of time because of the hazards of asbestos, and many people have recently shown interest in the hazards of substitute materials. However, comprehensive information about the types of asbestos substitutes, their use and health hazards, and references for the protection for the health of workers is limited. The purpose of this study is to provide people in the related industries with information on the types and health hazards of fibrous materials that can be used as asbestos substitutes. According to the patent resources from the United States and Europe, fibrous materials have been used to develop asbestos-free products since before 1980. Recently, the health hazards of asbestos substitutes have been assessed and many additional researches are required. However, only some of the substitute materials have been assessed for health hazards, and health hazard data has not been sufficient in many cases. Therefore, efforts should be made to minimize workers' exposure to substitute materials that do not contain asbestos.

In plain English

This short communication was a literature review, not a study of workers. The author reviewed United States and European patents for asbestos-free products, a World Health Organization (WHO) expert workshop report on asbestos substitutes, and cancer classifications from the International Agency for Research on Cancer (IARC) and the American Conference of Governmental Industrial Hygienists (ACGIH). The patents showed that asbestos-free products had been developed since before 1980. They used substitutes such as attapulgite, sepiolite, aramid, glass fiber and ceramic fiber in building materials, friction materials, gaskets and fabrics. In the WHO assessment the author summarized, potassium octatitanate fibers and long attapulgite fibers were rated high hazard, para-aramid medium, and carbon fibers, wollastonite and xonotlite low. Biopersistent synthetic vitreous fibers were rated high and nonbiopersistent ones low. Polypropylene, polyethylene and several other fibers were indeterminate for lack of data. IARC classifies erionite in Group 1 and refractory ceramic fibers and long attapulgite fibers in Group 2B. The author noted that only some substitutes had been assessed. The author concluded that efforts should be made to minimize workers' exposure to substitute materials.

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: Literature review (short communication) of patents, a WHO workshop report, and IARC and ACGIH classification documents
• Who was studied: No human study population. The sources were United States and European patents for asbestos-free products (cited patents dated 1975 to 2005, found through Google Patents), the WHO workshop report on asbestos substitutes, IARC monographs, and ACGIH threshold limit value documents.
• Exposure: Fibrous materials used as asbestos substitutes. These included man-made (synthetic) vitreous fibers, para-aramid, and natural inorganic fibers such as attapulgite, sepiolite and wollastonite. Erionite, carbon, cellulose, polymer fibers, whiskers and potassium octatitanate fibers were also reviewed.
• Main results:
  • According to the patents reviewed, products using asbestos substitutes had been developed consistently since before 1980.
  • Building materials: patents used attapulgite, cotton, mineral fiber, polyacrylamide, polypropylene, polyvinyl alcohol fiber, sepiolite and slag wool as substitutes.
  • Friction materials: patents used aramid, aromatic polyamide, attapulgite, carbon fiber, ceramic fiber, cotton, glass fiber, mineral wools and silica fiber as substitutes.
  • WHO assessment, para-aramid fibers: rated medium hazard. In part this was because the fibers are biopersistent.
  • WHO assessment, potassium octatitanate fibers: rated highly hazardous.
  • WHO assessment, attapulgite fibers: rated high hazard for long fibers and low hazard for short fibers. In animal respiratory testing, longer fibers caused tumors and shorter fibers did not.
  • WHO assessment, synthetic vitreous fibers: rated high hazard for biopersistent fibers and low hazard for nonbiopersistent fibers.
  • WHO assessment: carbon fibers, wollastonite, xonotlite and short attapulgite fibers were rated low hazard.
  • WHO assessment: polyethylene, polyvinyl chloride, polyvinyl alcohol and polypropylene fibers were rated indeterminate because of insufficient data. Graphite whiskers were also rated indeterminate.
  • IARC classifications: erionite fibers are in Group 1 (carcinogenic to humans). Fire-resistant (refractory) ceramic fibers and long attapulgite fibers are in Group 2B (possibly carcinogenic to humans).
  • IARC classifications: p-aramid fibers are in Group 3. In the article's table, wollastonite and sepiolite fibers are also listed as Group 3.
  • ACGIH, fire-resistant ceramic fibers: classified A2 (suspected human carcinogen), with a recommended threshold limit value of 0.2 f/cc.
  • ACGIH, glass wool, rock wool and slag wool fibers: classified A3 (confirmed animal carcinogen with unknown relevance to humans), with a recommended threshold limit value of 1 f/cc.
• The authors' conclusion: The author concluded that some fibrous substitutes may be carcinogenic or may affect health, and that only some have been assessed. On that basis, the author stated that efforts should be made to minimize workers' exposure to substitute materials that do not contain asbestos.
• Limitations the authors state:
  • Only some substitute materials have been assessed for health hazards, and some lack sufficient assessment data.
  • The WHO hazard groups (high, medium, low) are relative to each other and were not based on formal criteria or definitions.

Related studies

• Potential health hazards of ceramic ring lining material — D.R. Davis (1987)
• Minimising health hazards associated with derogated products and in-situ materials containing chrysotile contaminated with amphibole asbestos fibres — R.M. Howie (1999)
• International symposium on the health hazard evaluation of fibrous particles associated with taconite and the adjacent duluth complex. Introduction — R.P. Nolan (2008)
• Comparative hazards of chrysotile asbestos and its substitutes: A European perspective — P.T. Harrison, L.S. Levy, et al. (1999)
• Comments on "Comparative hazards of chrysotile asbestos and its substitutes: a European perspective" — H. Savastano (1999)
• Fibrous dust release from asbestos substitutes in friction products — S.A. Jaffrey, A.P. Rood, et al. (1992)

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