Even low-level lead exposure could affect your IQ, behaviour and ability to learn, experts have warned after a study involving 22 lipstick brands found that 55% contained trace amounts of the toxic element.

Underwriters Laboratories revealed that 12 of the lip products sampled tested positive for lead with the highest levels at 3.22 parts per million, the 'Daily Mail' reported.

Commenting on the findings Dr Sean Palfrey, medical director for the Boston Lead Poisoning Prevention Program, warned that even low-level lead exposure poses a serious health risk and could affect mental health.

"What we know now is that even the lowest levels of lead can harm your IQ, your behaviour, your ability to learn," he told Good Morning America, which commissioned the study.

"If you were serious about the public health aspects of lead poisoning you would not be looking at lipstick," Dr Halyna Breslawec, chief scientist for the Personal Care Products Council, added.

Currently, there are no standards set by the Food and Drug Administration in the US limiting levels in lipstick and it is up to manufacturers to decide on the safety tests performed.

Lead is not intentionally put in lipstick but many colour additives are mineral-based and contain trace levels of lead naturally found in soil, water and air.