There might be more than clean clothes coming out of your washer and dryer.

There has been growing concern and research into the chemicals released by laundry products, air fresheners, cleaners, lotions and other synthetically scented consumer products. Surprisingly, manufacturers are not required to disclose the ingredients used in fragrances, or in laundry products.

“This is an interesting source of pollution because emissions from dryer vents are essentially unregulated and unmonitored,” said Anne Steinemann, a University of Washington professor of civil and environmental engineering and of public affairs. “If they’re coming out of a smokestack or tail pipe, they’re regulated, but if they’re coming out of a dryer vent, they’re not.”

Analysis of the captured gases from washers and dryers found more than 25 volatile organic compounds, including seven hazardous air pollutants, coming out of the vents. Of those, two chemicals – acetaldehyde and benzene – are classified by the Environmental Protection Agency as carcinogens, for which the agency has established no safe exposure level.

“These products can affect not only personal health, but also public and environmental health. The chemicals can go into the air, down the drain and into water bodies,” Steinemann said.

The researchers estimate that in the Seattle area, where the study was conducted, acetaldehyde emissions from the top brand of laundry detergent would be equivalent to 3 percent of the total acetaldehyde emissions coming from automobiles. Emissions from the top five brands, they estimate, would constitute about 6 percent of automobiles’ acetaldehyde emissions.

“We focus a lot of attention on how to reduce emissions of pollutants from automobiles,” Steinemann said. “And here’s one source of pollutants that could be reduced.”

The project’s website also includes letters from the public reporting health effects from scented consumer products. Steinemann says that people’s reports of adverse reactions to artificial fragrances coming from laundry vents motivated her to conduct this study.

Steinemann recommends using laundry products without any fragrance or scent.