By George Patterson
On Feb. 28, 2006, the Occupational Safety and Health Administration (OSHA) finalized the new rule on hexavalent chromium, a rule likely to have a significant impact on the automotive refinish industry. Why this rule and what are its implications?
First of all, hexavalent chromium is used to impart corrosion protection to metal surfaces on a car when applied as a component in auto refinish primers. It was also widely used historically in topcoats to create bright red, orange and yellow colors that could be applied with a minimum number of coats. Unfortunately, hexavalent chromium has been linked to a number of serious health effects - including lung cancer, nasal septum ulcerations and perforations, asthma, skin ulcers, and allergic and irritant contact dermatitis.
Use in the automotive refinish industry carries with it the risk of exposure via inhalation of spray mists or direct skin or eye contact. As a result, and despite the undeniably attractive properties that it offers, use of hexavalent chromium has been in long-term decline - as substitute products have made their way to the market. The OSHA standard seems likely to accelerate that trend.
OSHA's new rule reduces the permissible exposure limit from 52ug/m3 to 5ug/m3, effective May 30, 2006. While 5ug/m3 is the new maximum, one is still subject to the standard if exposure is above the 0.5ug/m3 "exemption level" and many more provisions of the standard become applicable if exposure is greater than the "action level" of 2.5ug/m3. Historical data suggest that about 50 percent of all shops that use hexavalent chromium will exceed this 2.5ug/m3 during spray operations and some may exceed it during sanding operations.
The standard spells out requirements for air monitoring, demarcation of regulated areas, work clothing, hygiene practices, housekeeping, medical surveillance, hazard communications and record keeping. Very importantly, it specifies that exposure reduction is to be achieved primarily by establishing effective engineering and work practice controls, rather than depending on respirators and other personal protective equipment. Most provisions of the standard will take effect for larger employers (more than 19 employees) Nov. 27, 2006, and for smaller employers (19 or fewer employees) May 30, 2007. The exception is the requirement for engineering controls, which does not take effect until May 31, 2010.
How is one to know the best practices for reducing exposure during various auto refinish operations? Fortunately, the U.S. Environmental Protection Agency (EPA) has been working with the industry for a number of years to answer that exact question. Under the EPA's voluntary Design for the Environment (DfE) program, the agency has documented a number of "best practices" and provided check lists and other tools to help the body shop reduce employee exposure as well as emissions to the environment. These best practices stress use of HVLP guns, vacuum sanders, downdraft booths, etc. and can be found on the EPA's DfE Web site at www.epa.gov/dfe.
Finally, when a shop is reviewing its compliance options, it is important to bear in mind the truism repeated in the new standard: the best engineering control is substitution. To that end, all of the major paint manufacturers have worked hard to develop effective coatings that do not use hexavalent chromium.
| George Patterson has been with DuPont Performance Coatings for 38 years. He is a senior environmental fellow and provides guidance on regulatory and environmental issues for the company's research and development team. He holds a bachelor's degree in chemistry from Villanova University and a master's degree in chemistry from St. Joseph's University. His e-mail address is George.J.Patterson@USA.dupont.com.|