Is BPA-free plastic safe?

It's an unsettling thought: What if all the BPA-avoiding we've been doing—carefully checking for a "BPA-Free" label before any plastic purchase—has all been for naught? That BPA alternatives are actually just as harmful, if not worse?

The problem with BPA

The anti-BPA movement gained momentum in 2007 when parents took to legislatures to demand a ban on bisphenol-A (BPA). While they didn’t get it to the federal level, several states have banned the chemical in baby and children’s products, and a number of manufacturers have since removed it from water bottles and food containers. A victory, for sure, as the hormone disruptor has been linked to a boatload of issues, such as causing reproductive, immunity, and neurological problems, as well as childhood asthma, metabolic disease, type 2 diabetes, and cardiovascular disease.

What is it about BPA that’s so dangerous? To understand the far-reaching effects, it helps to know how the endocrine system works. After producing hormones in endocrine tissues (such as the ovaries, testes, and thyroid), the hormones are sent into the bloodstream like messengers, where they bind with hormone receptors throughout the body. By plugging into the receptors, the hormones activate responses throughout the body to control functions like growth, energy levels, and reproduction.

Here's where it gets shady: Because it has a similar shape to the hormone estrogen, BPA can bind with hormone receptors, too, and that's not good—the receptors get plenty of natural hormones. “BPA is acting on receptors that are already above thresholds because everyone has estrogen in their body,” says Frederick vom Saal, a University of Missouri biologist who studies endocrine disruptors. When the receptors get overloaded, it can alter cell function throughout the body.

And it doesn't take a lot to do damage. For BPA and other chemicals like it, even a weaker amount is exactly in the range to cause our system to go haywire, and that’s the amount we’re exposed to, vom Saal says. Indeed, studies show that BPA can significantly affect us in doses that are smaller than what’s used in traditional toxicology tests.

What does it mean for future generations? A new study finds low-dose prenatal BPA exposure may effect brain function.

The problem with BPA replacements

In order to keep our plastics plastic, all that BPA had to be replaced, and the other chemicals aren't much different: Their effects on health remain unclear at best—and scary at worst, according to research released earlier this month in Toxicological Sciences. BPA's replacements, related compounds like bisphenol-S (BPS) or bisphenol-F (BPF), actually appear to have similar—and sometimes even worse—endocrine-disrupting effects. “The chemicals have the same function [as BPA], which usually means they’re similar in structure, and therefore have similar health effects,” says Lindsay Dahl, deputy director of the organization Safer Chemicals, Healthy Families.

Our exposure to BPA-related chemicals occurs when they seep out of plastics and into food and drinks, as demonstrated during a 2011 Environmental Health Perspectives study when the majority of BPA-free commercial plastics tested were exposed to common-use stressors like microwaving, UV radiation, or steam sanitization. But it isn’t only plastic containers that expose us to these chemicals; researchers at the State University of New York at Albany also found BPF and BPS (in addition to the usual BPA) in canned foods, as well as in foods packaged in paper and even glass.

The suite of BPA-like substances we’re now being exposed to appear to join forces to wreak greater havoc on the body. In a 2013 study performed at the University of Texas Medical Branch at Galveston, exposure to multiple endocrine-disrupting chemicals, like BPS and nonylphenol, activated proteins involved in cell mutation or death, which can cause damage to genes—something that didn’t happen when cells were exposed to the chemicals individually.

Perhaps most troubling of all is recent research prompted by the Center for Environmental Health (CEH), an Oakland, California-based organization that seeks to protect people from toxic chemicals. It commissioned two independent labs to test 35 children’s sippy cups, and found that nine models labeled as BPA-free yielded moderate to high levels of estrogenic activity, meaning they contained chemicals that mimicked natural estrogen. Which specific chemicals were causing the estrogenic activity wasn’t determined, but some don’t think that makes much of a difference.

“If you went into a space with a [radiation detection device] and found radiation, would you stop to take additional time to find out where the radiation was coming from? It wouldn’t matter—you’d just want to get out,” says George Bittner, founder of CertiChem, an endocrine disruptor testing lab based in Austin, Texas, that examined the sippy cups.

It isn’t surprising that we have ended ended up replacing one toxic substance with others that might be just as bad. There are no federal laws requiring chemicals to be proven safe before they’re placed on the market. “So if a manufacturer decides to stop using BPA, they have no laws to follow that require them to use a safer chemical. As a result, they’ve been switching to chemicals that work the same,” Dahl says.

Where does this leave us?

Maybe we’re best to avoid plastics completely, especially when you hear about the weirdness surrounding some newer, supposedly safer alternatives like tritan copolyester, a plastic used in products made by Nalgene, Rubbermaid, and Tupperware. It’s free of the all the bisphenols, and according to the manufacturer Eastman Chemical Company, has been verified by third-party laboratories as safe. But in June 2013, the Washington Spectator reported that Eastman was suing CertiChem to put the kibosh on its findings that one of Tritan’s ingredients, triphenyl phosphate, is just as bad as BPA.

The courts ruled in Eastman’s favor later that summer, stating that CertiChem’s claims were false and misleading. But the controversy raises the question of how much we really know about the safety of any type of plastic. “Until we have some idea of what chemicals are added in all stages in making a final product, we will not be able to determine the safety of any plastic product,” says vom Saal. For now, sticking to leach-free materials like glass or stainless steel as much as possible seems to be your best bet.