What do Nalgenes, Crate and Barrel wine glasses and Born Free baby bottles have in common? All of these reusable, hard plastic products leach estrogen-mimicking chemicals into the body, according to a new study published in Environmental Health. These estrogenic chemicals can cause a host of adverse health effects, especially in the fetal and infant stages, including altered learning abilities, aggressive behavior, and altered rates of growth.

The irony is that companies like Nalgene modified the chemical composition of their products to avoid precisely these problems. After the adverse effects of bisphenol A (BPA), a chemical commonly found in clear, reusable plastic products, were discovered, manufacturers turned to polycarbonates (PC) resins as an alternative. Yet this study found that many PC-replacement products still leak chemicals with significant levels of estrogenic activity (EA), particularly if they are exposed to heat or sunlight.

The good news? Some of the products included in the study—including Topas and Zeonor water bottles—were free of detectable EA, indicating that manufacturers can make comparably priced, durable and reusable plastic containers that don’t carry the same health risks. As the authors put it, “It is not necessary to forgo these advantages of plastic to avoid the release into foodstuffs or the environment of chemicals having EA that may have potential adverse effects on our health or the health of future generations.”