The top-selling brands of laundry soap and air fresheners give off toxic chemicals that are not listed on their labels, according to a study from the University of Washington.

The chemicals included acetone, the main ingredient in nail-polish remover, according to Anne Steinemann, an engineering and public affairs professor. She said she started her work because people complained that air fresheners in restrooms were making them sick.

"I was surprised by both the number and the potential toxicity of the chemicals that were found," Steinemann said. She said five of six products she tested emitted substances the Environmental Protection Agency says are not safe at any level.

The researcher did not disclose which six products she tested. The products were put in an isolated space at room temperature, and then the air was tested for the compounds.

Makers of products such as air fresheners and the dryer sheets, fabric softener and detergent she tested do not have to disclose their ingredients.