A chemical commonly used in lipsticks, face washes and toothpaste may cause heart and muscle problems, according to scientists.
They found triclosan, which is in hundreds of household products, can hinder the process by which muscles, including the heart, receive signals from the brain.
In tests on mice, they noted a ‘dramatic’ 25 per cent reduction in heart function within 20 minutes of exposure, and warned there is ‘strong evidence’ it could affect human health.
However regulators and other experts insist triclosan levels in products are safe, and that the doses injected into the mice were higher than those to which humans would ever be exposed.
Although previous studies have found that triclosan may have links to thyroid and fertility problems, this is the first time its effects have been tested on muscles.
Scientists had thought that the chemical – which was devised to prevent bacterial infections in hospitals – was metabolised quickly by the body without harmful effects.
However, the researchers at the University of California say it may remain active and be transported to organs, causing damage.
Professor Isaac Pessah, who led the study, published in the Proceedings of the National Academy of Sciences, said: ‘These findings provide strong evidence that it is of concern to both human and environmental health.