A study published in the journal Environmental Health found that a number of plastic containers — including blue Nalgene and Camelbak water bottles, Lock and Lock food storage containers, and AVENT baby bottles — leached substances that can mimic estrogen and upset the body's chemical balance. In some products, researchers observed chemical seeping occur under normal use conditions, while others leached only after exposure to UV light or heat from a microwave or dishwasher.
While the study didn't name the specific endocrine-disrupting chemicals found in the containers, previous research shows that estrogen-mimicking compounds could have a number of serious health effects. Triclosan, in particular (a chemical found in many antimicrobial soaps and some cosmetic products) is a known carcinogen.
Click over to Mother Jones to find out whether your bottle is on the blacklist. We don't know about you, but we're seriously thinking about making the switch over to glass.