What they are: Pronounced ‘tha-lates,’ these chemicals are used to make plastics more soft so they don’t become brittle and break. They’re found in electronics, toys and more. They’re used to preserve the texture of some cosmetics and toiletries.
How it might harm: Phthalates may interfere with various hormonal signaling. A 2011 study by the University of Michigan of 1,700 adult and teens found that those who fell in the highest 20 percent for exposure to di(2-ethylhexyl) phthalate or DEHP – as measured in their urine – were at an increased risk of decreased thyroid function. One of the symptoms of hypothyroidism is weight gain. Another study that analyzed breastmilk samples from 130 women, meanwhile, found that those who were taking in higher concentrations of phthalates had a slight decrease in testosterone levels.
How to avoid it: Look for ingredients that include the word phthalate. In cosmetics, the chemicals sometimes go under the acronyms DBP and DEP. Also, parents of infants should buy children’s toys that are free of phthalates – after all, they tend to end up in their mouths.