Triclosan, an antibacterial chemical widely used in hand soaps and other personal-care products, hinders muscle contractions at a cellular level, can drain muscle strength and hampers cardiac function, according to scientists at the University of California, Davis, and the University of Colorado. The findings appear online in the Proceedings of the National Academy of Sciences of the United States of America.

“Triclosan is found in virtually everyone’s home and is pervasive in the environment,” warns researcher Isaac Pessah. “These findings provide strong evidence that the chemical is of concern to both human and environmental health.”

Triclosan is commonly found in antibacterial personal-care products such as hand soaps, as well as deodorants, mouthwashes, toothpaste, bedding, clothes, carpets, toys and trash bags. The U.S. Environmental Protection Agency in 1998 estimated that more than 1 million pounds of triclosan are produced annually in the United States, and that the chemical is detectable in waterways and aquatic organisms ranging from algae to fish to dolphins, as well as in human urine, blood and breast milk.

Lab tests show that triclosan has serious effects on the heart muscle.

“The effects of triclosan on cardiac function were really dramatic,” says Nipavan Chiamvimonvat, a study co-author. “Although triclosan is not regulated as a drug, this compound acts like a potent cardiac depressant in our models.”