There's no doubt about it: We live in a plastic world.
We wake up in the morning and brush our teeth with a plastic toothbrush and toothpaste squeezed from a plastic tube. We pour ourselves cereal from a plastic bag and milk from a plastic carton, pack our lunch in plastic containers, work all day on a computer monitor and keyboard made of plastic, and return home for a nice dinner of chicken noodle soup from a can lined with, you guessed it: plastic. We might as well be Barbie.
You’ve probably seen some of this plastic labeled “BPA free,” but does that make it safer?
Bisphenol A (BPA) is the main component of polycarbonate, the hard, clear plastic sometimes used to make water bottles, baby bottles, food storage containers and other items like contact lenses, CDs, receipts and electronics devices. BPA is even used in places you wouldn't normally think of, like in the epoxy resins that form the protective lining in tin cans and in dental sealants.
If you've noticed the little arrows stamped on plastic items with numbers inside, the number to look for here is 7. Although not all plastics labeled "7" contain BPA, it's still a good identifier, as are the letters "PC."
Is BPA Safe?
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: 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.
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: 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: Zandonella].
In the U.S., the Food and Drug Administration (FDA) regulates BPA's use in food contact materials, like food cans and water bottles. In 2010, the FDA undertook a four-year review of BPA studies. In 2014, the U.S. Food and Drug Administration (FDA) upheld its previous no-observed-adverse-effect level (NOAEL) for BPA of 5 mg/kg of body weight per day.
As of October 2023, the FDA is reviewing a 2022 petition to revoke authorization for BPA.
FDA no longer provides for the use of BPA in baby bottles, sippy cups and infant formula — not because it deemed BPA unsafe for infants, but because manufacturers had already stopped using BPA due to consumer pressure [source: FDA].
In April 2023, the European Food Safety Authority (EFSA) responded to the latest BPA research by lowering its safe level of BPA intake to 0.2 ng/kg body weight per day (0.2 ng is 0.2 nanograms or 0.2 billionths of a gram) — 20,000 times lower than it's previous safe level of 4 μg/kg body weight per day (4 μg is 4 micrograms or 4 millionths of a gram).
The EFSA estimates that current levels of dietary exposure to BPA may be "two to three orders of magnitude higher than the new tolerable level," which poses "a health concern for all age groups of the general population."
The EFSA's new limit is simply a recommendation; it remains to be seen how EU lawmakers will respond to this new guidance, and if the U.S. will follow suit.
What Does 'BPA Free' Mean?
The label "BPA free" indicates that a plastic does not contain bisphenol A. Unfortunately, BPA-free products often contain other bisphenols, like bisphenol F and bisphenol S, which may pose some of the same risks as BPA.
Depending on who you listen to, bisphenols may or may not be a cause for concern, but there's no doubt that you're exposed.
A 2004 study by the U.S. Centers for Disease Control and Prevention detected BPA in "nearly all of the people tested" [source: CDC]. New methods for detecting BPA in human urine suggest that exposure may be greater than previously estimated [source: Consumer Reports].
You can't escape BPA entirely, but you may be able to limit your exposure. BPA is more likely to leach into food or water when exposed to high temperatures and as it ages [source: Britannica]. If you are concerned about BPA in food and beverage containers, you can switch to glass or stainless steel containers.
If BPA turns out to be harmless to humans, at least you can say you're doing your part for the Earth.