Overexposure to a chemical called triclosan, which is found in many brands of antibacterial soap and toothpaste, could make you susceptible to allergies such as hay fever, say the researchers. And it looks like another chemical commonly found in plastic products, called bisphenol A (BPA), could affect your immune system, they claim.
In tests the researchers analysed the amount of BPA and triclosan in volunteers' urine and discovered higher amounts of both chemicals were linked with high antibody levels, which suggests a problem with the functioning of the immune system. The volunteers who had the highest levels of triclosan in their urine were also more likely to have been diagnosed with allergies.
Both chemicals are labelled as endocrine-disrupting compounds - which, according to scientists, means they affect your hormones. But while it was previously thought that they were harmless in small amounts, a growing number of experts are concerned that they may be dangerous in low levels after all.
Only a few days ago the European Commission agreed to ban BPA from baby bottles in EU countries by the middle of next year, while last month Canada became the first country to label BPA as a toxic substance. It's found in a variety of plastic products, including bottles and the lining of food tins.
Are you worried about the number of chemicals in everyday products such as soap and plastics?