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Occupational Asbestos Exposure Monitoring of Brake Replacement Activities on All-terrain Vehicles (ATVs)

Abstract No:

1541 

Abstract Type:

Professional Poster 

Authors:

M Holton1

Institutions:

1Ramboll, doylestown, PA

Presenter:

Michael Holton  
Ramboll

Description:

This industrial hygiene study assessed the potential for exposures to asbestos while removing asbestos-containing automotive friction products, specifically brakes on ATVs. The project consisted of: a) the identification of which ATVs had asbestos-containing brakes; b) performing exposure monitoring (both personal and area) of a mechanic during the removal of the asbestos-containing brakes; and c) verification that the brakes used were asbestos containing.

Situation / Problem:

Asbestos has not been wholly banned as a constituent ingredient in products in the United States. In 2016, asbestos was identified for health risk evaluation by the USEPA under the purview of the 2016 amendments to the Toxic Substance Control Act (TSCA). The amendment requires the USEPA to determine whether identified substances pose an unreasonable risk to health or the environment. During the importation of ATVs into a country with a ban on the use of asbestos-containing products, asbestos was discovered in components (i.e., brakes), believed to be asbestos free. Following this discovery, the authors endeavoured to determine the source of the asbestos, the universe of potential ATV components which may contain asbestos, and the potential for exposures from the replacement of these brakes. While the replacement of brakes by mechanics has been studied and published in the peer reviewed literature, the replacement of brakes associated with ATVs, has not been characterized. In order to fill this gap, the authors assessed the potential for exposure related to asbestos-containing brake replacements located on ATVs.

Methods:

Bulk testing of brakes was performed by accredited laboratories in the U.S. using polarized light microscopy (PLM) and transmission electron microscopy (TEM) by EPA/600/R-93/116 method. All samples were prepared as nonorganically bound materials (NOB). After the initial bulk testing phase, the ATVs with asbestos-containing brakes were identified for occupational exposure monitoring. The sampling strategy for the occupational monitoring of mechanics was conducted over the course of a single day consisting of the collection of background area samples, perimeter area samples, and personal samples. Perimeter area sampling was performed prior to any work being performed, while work was being performed, and after work was performed. Personal sampling was conducted on one mechanic during eight brake replacements. During each brake replacement session, three personal air samples were collected in the mechanic's breathing zone during the process of removing the brakes and replacing them with nonasbestos-containing replacement brakes. At the conclusion of the study, the brakes were analyzed to confirm the asbestos content.

Results / Conclusions:

Perimeter area and personal occupational exposure monitoring was analysed via phase contrast microscopy (PCM) via NIOSH 7400. Samples where any fibers were detected were further analysed by transmission electron microscopy (TEM) via NIOSH 7402. Personal occupational exposures during brake replacement ranged from <0.008 to <0.016 f/cc tasked based by PCM. Area samples ranged from <0.008 to 0.011 f/cc (short term) by PCM; analysis by TEM did not identify any asbestos fibers. All background samples ranged from <0.003 to <0.006 f/cc by PCM. Brakes removed during the work were sent for analysis for verification that they were asbestos-containing. The brakes contained actinolite and/or chrysotile and tremolite ranging from 6% to 44.3% total asbestos by TEM.

Exposure monitoring during the removal of asbestos-containing brakes did not detect any asbestos fibers. This study is highly suggestive that this work when consistent with OSHA's wet method for automobile brake removal would not result in exposures approaching the OSHA PEL or excursion limit for asbestos.

Primary Topic:

Exposure Assessment Strategies

Secondary Topics:

Aerosols

Co-Authors

Please add your co-authors below. Co-authors are listed for professional courtesy and will not be communicated with regarding the decision notification or any on-site logistics, if accepted. Only the primary presenter listed is expected to attend and present the content on-site.

Jennifer Ellis, Evan Anderson, Robert Adams, Benjamin Ellis

Acknowledgements and References

List any additional people who worked on the project or provided guidance and support along with details on the role they played in the research. (Please include first name, last name, organization, city, state and country).

None

Practical Application

How will this help advance the science of IH/OH?

This will present information on assessment of exposures for a previously unaddressed activity.

Learning Level

What learning level is the presentation content geared towards?

Competent - can perform to basic standards; has a thorough understanding of the content area but limited practical/work experience in the application of the content/concepts.