Brake Lining Decomposition Products

Lynch, Jeremiah

doi:10.1080/00022470.1968.10469224

Cited by 45 publications

(21 citation statements)

References 4 publications

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“…The US Public Health Service reported a study by Lynch [1968] of decomposition products from brake linings. It found that a small fraction of asbestos fibers survived intact after normal brake use.…”

Section: Decomposition Of Asbestos Fibers In Brakesmentioning

confidence: 99%

Asbestos in brakes: Exposure and risk of disease

Lemen¹

2004

American J Industrial Med

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Asbestos has been incorporated into friction products since the early 1900s. Epidemiological studies have been equivocal in their analysis of the incidence of disease among mechanics servicing brakes. Decomposition of asbestos occurs during the normal usage of the brake due to thermal decomposition into forsterite, although not all asbestos is so converted. Short fibers, below 5 microm in length, are also found in brake products. Several facts are discussed including the toxicity of the remaining asbestos fibers, short asbestos fibers, and the health implications of exposure to forsterite. Control methodologies, when used appropriately, have reduced exposure to asbestos during brake servicing, but have not been able to entirely eliminate exposure to asbestos, thus bring into question the controlled use of asbestos for friction product such as brakes. Even the so called "controlled" use of asbestos containing brakes poses a health risk to workers, users, and their families.

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Section: Decomposition Of Asbestos Fibers In Brakesmentioning

confidence: 99%

Asbestos in brakes: Exposure and risk of disease

Lemen¹

2004

American J Industrial Med

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“…Of the small number of residual intact chrysotile fibers, most remain embedded in the plastic binding material. Less than 0.1-1% of the fibers in brake dust are free chrysotile, the majority of which are short fibers, <1 µm in length (Lynch, 1968;Hatch, 1970;Davis and Coniam, 1973;Williams and Muhlbaier, 1982;Wong, 2001). Of note, a considerably higher concentration (2-15%) of free chrysotile has been detected in used brake linings .…”

Section: Discussionmentioning

confidence: 97%

“…Chrysotile is a major component of friction materials, accounting for 30-80% of the finished product (Greenberg and Darcy, 1992). However, according to most studies, the concentration of respirable chrysotile liberated by various brake maintenance operations, such as 'blowing out' brake surfaces and grinding brake shoes, is low (Lynch, 1968;Hickish and Knight, 1970;Lorimer et al, 1976;Rodelsperger et al, 1986). In a number of industrial hygiene reports detailing asbestos exposures among automotive mechanics, the concentration of airborne asbestos has been below the Occupational Safety and Health Administration's permissible exposure limit (PEL) of 0.1 fiber/cm 3 (National Institute for Occupational Safety and Health, 1980a,b;Cheng and O'Kelly, 1986;Rodelsperger et al, 1986;Kauppinen and Korhonen, 1987).…”

Section: Discussionmentioning

confidence: 99%

Exposure to Brake Dust and Malignant Mesothelioma: A Study of 10 Cases with Mineral Fiber Analyses

2003

The Annals of Occupational Hygiene

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Objectives: A large number of workers in the USA are exposed to chrysotile asbestos through brake repair, yet only a few cases of malignant mesothelioma (MM) have been described in this population. Epidemiologic and industrial hygiene studies have failed to demonstrate an increased risk of MM in brake workers. We present our experience of MM in individuals whose only known asbestos exposure was to brake dust and correlate these findings with lung asbestos fiber burdens.Methods: Consultation files of one of the authors were reviewed for cases of MM in which brake dust was the only known asbestos exposure. Lung fiber analyses were performed using scanning electron microscopy (SEM) in all cases for which formalin-fixed or paraffinembedded lung tissue was available.Results: Ten cases of MM in brake dust-exposed individuals were males aged 51-73 yr. Nine cases arose in the pleura and one in the peritoneum. Although the median lung asbestos body count (19 AB/g) is at our upper limit of normal (range 0-20 AB/g), half of the cases had levels within our normal range. In every case with elevated asbestos fiber levels by SEM, excess commercial amphibole fibers were also detected. Elevated levels of chrysotile and non-commercial amphibole fibers were detected only in cases that also had increased commercial amphibole fibers.Conclusions: Brake dust contains exceedingly low levels of respirable chrysotile, much of which consists of short fibers subject to rapid pulmonary clearance. Elevated lung levels of commercial amphiboles in some brake workers suggest that unrecognized exposure to these fibers plays a critical role in the development of MM.

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“…Automotive friction products (e.g., brakes) manufactured in the United States contained approximately 20-60% chrysotile asbestos beginning in the early 1900s (Lynch, 1968;Paustenbach et al, 2003). There is no data or chemical testing showing that amphibole asbestos was ever used in the manufacture of brakes.…”

mentioning

confidence: 99%

“…There is no data or chemical testing showing that amphibole asbestos was ever used in the manufacture of brakes. In fact, virtually all of the scientific data demonstrate that chrysotile was the mineral form universally used for this purpose in the United States and Europe (Rosato, 1959;Lynch, 1968;Anderson et al, 1973;Langer and McCaughey, 1982;Weir et al, 2001;Blake et al, 2003;Madl et al, 2008;Sheehy et al, 1989;Jacko et al, 1973).…”

mentioning

confidence: 99%