Reviewed By Louise Chang, MD
What is bisphenol A?
Bisphenol A is a chemical found in polycarbonate plastic and epoxy resins.
Polycarbonate plastics are used in certain food and drink packaging (including some water bottles and baby bottles) and also in compact discs, computers, impact-resistant safety equipment (such as helmets and goggles), and medical devices.
Polycarbonate plastics that contain bisphenol A usually have a No. 7 on the bottom, within the "chasing arrows" used to sort plastics for recycling, according to the National Institute on Environmental Health (NIEHS). But the American Chemistry Council, an industry group, strongly advises against using those recycling codes for any purpose other than sorting your recycling, since the numbers aren't about bisphenol A or other plastic chemicals.
Epoxy resins line metal products such as canned foods, bottle tops, and
water supply pipes.
Is bisphenol A safe?
In a draft report, government scientists note "some concern" about bisphenol A's possible effects, based on lab tests in rodents. But that report isn't final, and the scientists aren't calling bisphenol A unsafe.
Those scientists, who work for the National Toxicology Program, agree with their advisory panel's 2007 conclusion that there is "some concern" about possible neural and behavioral effects in fetuses, infants, and children at current human exposures. The NTP also has "some concern" for bisphenol A exposure effects in the prostate gland, mammary gland, and an earlier age for puberty in females. A panel of experts convened by the NTP last year wasn't as concerned about those potential effects.
None of that research was done on people. The American Chemistry Council, an industry group, says that the potential human exposure to bisphenol A is "extremely small" and that bisphenol A poses no known risks to human health.
"Consumers would have to eat more than 500 pounds of food and beverages in contact with polycarbonate plastic or epoxy resins every day of their lives to exceed exposure levels determined to be safe by the European Food Safety Authority and the U.S. Environmental Protection Agency," states the American Chemistry Council, adding that typical human exposure to bisphenol A "is approximately 1,000 times below the safe exposure levels."
How are people exposed to bisphenol A?
People mainly get exposed to bisphenol A through their diet. Bisphenol A can leach into food from food and beverage containers lined with epoxy resin coatings and from products such as polycarbonate tableware, food containers, water bottles, and baby bottles, according to the NIEHS.
Does heating polycarbonate products or running them through the dishwasher increase leaching of bisphenol A?
Yes, but not enough for concern, according to the American Chemistry Council. "Although the level increases slightly, it's still far below the science-based safety standard by at least a factor of 100 or so," says Steven Hentges, PhD, of the council's Polycarbonate/BPA Global Group.
In January 2008, a University of Cincinnati researcher who studied polycarbonate plastic exposed to boiling liquid told WebMD that while there is little direct evidence that bisphenol A poses a risk to humans, he sees "clear reason to proceed cautiously."
How common is bisphenol A exposure?
Human exposure to bisphenol A is "widespread," states the NIEHS web site. The NIEHS cites a 2003-2004 CDC report that detected bisphenol A in 93% of 2,517 urine samples provided by Americans aged 6 and older.
How can I avoid exposure to bisphenol A?
The NIEHS provides the following tips for people who choose to limit their exposure to bisphenol A:
- Don't microwave polycarbonate plastic food containers. Polycarbonate plastic is strong and durable, but over time it may break down from use at high temperatures.
- Reduce your use of canned foods.
- When possible, opt for glass, porcelain, or stainless steel containers, particularly for hot food or liquids.
- Use baby bottles that are free of bisphenol A.
The American Chemistry Council disagrees. "These products are safe for use," says Hentges. "There isn't a risk to reduce."
SOURCES: WebMD Medical News: "Cap's Off on Plastic Chemical Concerns." NIEHS: "Since You Asked: Bisphenol A." American Chemistry Council: "Bisphenol A Fact Sheet." WebMD Medical News: "Plastic Safety Chemical Weighed." WebMD Medical News: "Hot Liquids Ups BPA From Plastic Bottles."
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