A new study surveying mechanics involved in removing and replacing clutches in manual transmission vehicles indicates that in most cases very little risk of asbestos exposure exists.

The presence of asbestos in friction-reducing components used in brakes and manual transmission clutches has long been thought to pose high risks of asbestos exposure for mechanics, but in fact this may not be the case for all types of mechanics.

The study, carried out by researchers at the University of New Haven in West Haven, Connecticut, is entitled “Asbestos exposure of mechanics performing clutch service on motor vehicles,” and appeared in the March 2008 issue of the “Journal of Occupational and Environmental Hygiene.”

During most of the twentieth century, break pads and clutch pads contained anywhere between 25% and 60% chrysotile asbestos, posing asbestos exposure risks for mechanics involved in replacing and repairing those components.

Many companies once released information stating that chrysotile asbestos was safe and did not cause cancer; however this is now known not to be the case.

The researchers carrying out the study noted that there was plenty of risk assessment data for mechanics involved in performing brake service, but very little for mechanics performing clutch service on manual transmission cars. The study reported here was, therefore, carried out to “assess historical asbestos exposures of mechanics performing clutch service on motor vehicles.”

Since the 1960s, surveys carried out on mechanics involved in brake servicing have shown that airborne asbestos levels were frequently below the current Occupational Safety and Health Administration permissible exposure limit of 0.1 asbestos fibers per cubic centimeter of air.

To determine whether clutch service mechanics were subject to the same low airborne asbestos fiber concentrations, the researchers analyzed air samples taken during the removal of asbestos-containing clutch pads, and also analyzed pads and debris.

In addition, another research team carried out a telephone survey of automotive mechanics working prior to 1975. The mechanics were asked questions relating to the duration and frequency of clutch service work they performed. The data was used to help determine the average length of time workers took to complete clutch services.

The researchers found that like brake service mechanics, clutch service mechanics were for the most part working in airborne asbestos concentrations of well below the permissible exposure limit of 0.1 fibers per cubic centimeter. In fact, the average airborne asbestos concentration of the samples analyzed was so low that the average asbestos exposure for clutch mechanics was found to be 0.0016 fibers per cubic centimeter of air.

This entry was posted on Thursday, April 24th, 2008 at 9:45 am and is filed under Asbestos Exposure. You can follow any responses to this entry through the RSS feed. Responses are currently closed, but you trackback from your own site.