What Does ‘BPA Free’ Mean and Why Does It Matter?

Since the 1990s, there has been an ongoing debate surrounding the safety of BPA.

BPA and Mice

In August 1998, the geneticist Dr. Patricia Hunt was studying the ovaries of mice and noticed her data behaving strangely. For some reason, chromosomal errors leaped from 2 percent to 40 percent in the mice making up her control group. These abnormalities eventually would lead to miscarriage and birth defects. The determined cause: BPA[source:[source:Neimark].

After running more tests, Hunt learned that all of the mice cages and water bottles were contaminated with BPA that had leached out of the polycarbonate plastic. When she replaced the plastics, the mice cells returned to normal. Her work revealed that exposure to BPA disrupts fetal development in mice, as well as the eggs of the fetus that will be responsible for the next generation.

Since her discovery, Hunt and other researchers have become convinced that BPA is a cause for concern in humans, as well as mice.

Critics of the studies linking BPA to cell damage, however, argue that the research isn’t conclusive. Humans process BPA differently than mice, so we won’t necessarily experience the same health effects. Others say that the BPA that finds its way into the food supply is safely below the limits set by the U.S. Environmental Protection Agency.

Endocrine Disruptors

BPA is a difficult substance to nail down; it doesn’t behave like a typical toxin. While other chemicals labeled as toxic have clear-cut impacts (asbestos exposure leads to cancer, lead poisoning causes reduced mental capacity), BPA is sneakier.

Rather than harm the body outright, BPA is an endocrine disruptor. It changes the way our body’s hormones function, mimicking our own natural hormones — in this case, estrogen.

Estrogen can alter the behavior of more than 200 genes, which control the growth and repair of nearly every organ and tissue in the body[source:[source:Environmental Working Group]. Among other things, estrogen affects fetal development, cell structure and the onset of puberty, and your body’s cells are highly sensitive to even tiny changes in estrogen levels.

Studies show that doses of BPA between 2 and 20 micrograms per kilogram of body weight alter the reproductive system of male mice.

So while some early toxicity studies done on BPA determined that high doses were safe, it’s important to remember that BPA doesn’t behave like your average toxin. Scientists aren’t sure why, but high amounts of BPA don’t always seem to affect genes the same way low doses do.

It sounds counterintuitive, but with BPA, it turns out that less is actually more[source:[source:Zandonella].