Phil Comier at work in the Highland East Automotive Machine Shop.
By replacing traditional degreasers with safer approaches businesses can protect workers and reduce harmful chemicals in the environment.
Auto shops often use parts cleaners—baths of solvents that are used to dissolve grease and grime from, for example, the components of a carburetor. “Even if the baths are closed, they still emit a lot of vapors and produce hazardous waste” said Diana Ceballos, an assistant professor in the University of Washington (UW) Department of Environmental and Occupational Health Sciences (DEOHS) and expert on assessing exposures to chemicals such as volatile organic compounds (VOCs), a common component of commercial degreasers.
Even if a degreaser is used only for a short time, it can be a significant source of exposure to harmful chemicals. “Because degreasers tend to be used sporadically, I didn’t expect levels of VOCs in the body to be as high,” explained Ceballos. “But it turns out a few minutes of product use can provide a lot of exposure.”
VOCs are harmful chemicals that evaporate quickly and can cause both immediate health effects such as irritation of the eyes and throat and long-term effects such as cancer or kidney damage. Not only can these degreasers cause problems for workers, they can also end up contaminating air and stormwater around the shops where they are used.
Currently, the King County Hazardous Waste Management Program is working to help auto shops adopt safer degreaser practices. Safer alternatives include products with fewer VOCs that may be aqueous-based rather than solvent-based or new technologies that rely on sonication or highly potent microbes called enzyme digestors for cleaning parts rather than solvent baths.
“It’s a good time for this kind of intervention,” Ceballos explained. “A few years ago, we just weren’t ready with these safer alternatives. Now businesses are aware that EPA [the U.S. Environmental Protection Agency] will likely eventually ban traditional degreasers.* The state is supporting these businesses to switch to safer products by offering technical support and financial incentives before they have to make the change more abruptly.”
To measure the effect of the switch to safer degreasers, Ceballos and her team have been collecting blood, urine, and exhaled breath samples from workers in auto shops both before and after shifts during which they used traditional degreasers and safer approaches. They have also collected air samples from areas of the shops where workers spend the most time to look at levels of exposure.
The King County Hazardous Waste Management Program, Seattle & King County, the U.S. Center for Disease Control and Prevention (CDC), Division of Laboratory Sciences at the National Center for Environmental Health, and Jia Laboratory at the University of Memphis have been crucial partners for Ceballos and her team. King County supported networking and recruitment to reach shops that would be willing to participate in the study. They also connected the team to the Washington Department of Ecology and state-level interventions. Additionally, they have provided incentives for workers who participate in the study, support for two interns, costs associated with the air and breath analysis, and translation services.
The CDC, through a technical assistance request with King County, helped with blood and urine sample collection and analysis, and provided materials including boxes and pre-paid shipping labels. Some of the blood samples go to her co-PI in this study, Judit Marsillach, an assistant professor in DEOHS, to look at protein biomarkers in blood to evaluate the effect of degreasers in the body. A team from the University of Memphis helped collect and analyze air and breath samples. Each sample would be analyzed for dozens of VOCs including benzene, methylene chloride, ethylbenzene, and others.
As part of her project, Ceballos worked with Maria Tchong-French, a research scientist, and Sarah Fish, a graphic designer, both in DEOHS, to create a fact sheet outlining the health risks associated with degreasers and tips for creating safer workplaces. “We drew on the vast knowledge of our partner groups and worked hard to make the fact sheet more intuitive and interactive,” said Ceballos. The result is a product unlike anything else out there.
The technical guide is one piece of information that the team provides to study participants along with the results of their blood and urine analysis. They also have expert team members available to answer any questions or discuss results.
A $40,000 pilot grant from the UW Interdisciplinary Center on Exposures, Diseases, Genomics & Environment (EDGE Center) supported Ceballos’ and Marsillach's work on this project. An additional $10,000 supplement from the EDGE Center specifically supported the team's community engagement efforts, including the production of the fact sheet.
Questions about the study can be directed to Dr. Ceballos at dmco25@uw.edu.
*On December 10, 2024 the U.S. Environmental Protection Agency banned the use of two common, cancer-causing solvents—trichloroethylene (TCE) and perchloroethylene (PCE), both of which have exposed communities to health hazards through contaminated water. The new ban will prohibit most uses of TCE within one year and require a phaseout of PCE for most industrial uses in less than three years. Use in dry cleaners will be phased out in less than 10 years. These bans follow a ban on most uses of another harmful solvent—methylene chloride—which was finalized by the EPA on April 30, 2024.