"Most plastic products, from sippy cups to food wraps, can release chemicals that act like the sex hormone estrogen, according to a study in Environmental Health Perspectives.

The study found these chemicals even in products that didn't contain BPA, a compound in certain plastics that's been widely criticized because it mimics estrogen.

Many plastic products are now marketed as BPA-free, and manufacturers have begun substituting other chemicals whose effects aren't as well known."

Jon Hamilton reports for NPR's All Things Considered March 3, 2011. [2]