If you’re a label reader you’ve most likely seen triclosan listed as an ingredient in one of your products. Triclosan is an antibacterial and antifungal agent found in a myriad of household and personal care products such as shampoos and soaps. But a new study suggests it may also be an environmental contaminant.

The study investigated whether exposure to triclosan was linked to a higher risk of S. aureus (a staphylococcus bacterium) colonisation in the nose, a risk factor for many types of infection. Nasal swabs from participants revealed that 40% had detectable levels of triclosan. Among those with low levels of triclosan in their noses, 27-32% had S. aureus colonies compared to 64% of people with high levels of triclosan. When S. aureus is exposed to triclosan, they were better able to attach to human proteins – a vital step in colonisation – as well as plastic and glass surfaces.

According to researchers, based on these findings, along with studies on the effect of triclosan on the endocrine system and muscle function, adding triclosan to consumer products needs urgent reevaluation.