From NPR: Study: Most Plastics Leach Hormone-Like Chemicals

The testing showed that more than 70 percent of the products released chemicals that acted like estrogen. And that was before they exposed the stuff to real-world conditions: simulated sunlight, dishwashing and microwaving, Bittner says.

The team concentrated on BPA-free baby bottles and water bottles, Bittner says, “and all of them released chemicals having estrogenic activity.” Sometimes the BPA-free products had even more activity than products known to contain BPA.

Primary Source: Most Plastic Products Release Estrogenic Chemicals: A Potential Health Problem That Can Be Solved