Stop right there. Are you about to use makeup containing this dangerous ingredient…?

A new study from Columbia University’s Mailman School Of Public Health has found that there’s one makeup ingredient you should avoid at all costs.

The ground-breaking study, which was published in the PLOS ONE Journal, revealed that regular use of phthalates, typically found in colour cosmetics, fragrances, nail polish and body washes, can result in a lowered IQ.

Researchers measured the levels of four different phthalates in the urine of pregnant mothers, then tested the IQ levels of each of their children at age 7. They concluded that mothers with the highest phthalate concentrations gave birth to children with 6-8 lower IQ points than those with the lowest phthalate exposure.

Mothers with the highest phthalate concentrations gave birth to children with 6-8 lower IQ points than those with the lowest phthalate exposure.

They also found an association between phthalate levels and perceptual reasoning, as well as the length of time it took children to comprehend information.

The exact reasons as to why IQ levels were so much lower in individuals with higher rates of phthalate exposure are still unknown, though researchers have speculated phthalates may disrupt thyroid hormones, essential to brain development in children.

Regular exposure to phthalates has already been linked to breast cancer in several studies. Phthalates can also be found in plastic, glue and linoleum.

Have your say: Are you concerned about the ingredients in the beauty products you use?