A Common Plastic Comes Under Scrutiny
Polycarbonate plastic is long-lasting, impact-resistant, and clear, making it a perfect
material for baby bottles, refillable water bottles, sippy cups, and many other food
and beverage containers. It is also found in eyeglass lenses, compact discs, dental
sealants, and plastic dinnerware. And, as a resin, it forms the protective lining
for metal food and beverage cans.
But recent research has raised concerns over the health effects of a chemical used
in the manufacture of polycarbonate — bisphenol A (BPA). Some studies have found that
BPA can leak trace amounts from polycarbonate containers and resin linings into foods
and beverages. In tests on laboratory animals, BPA appears to copy or disturb the
hormone estrogen and affect the reproductive system. This could possibly raise the
risk for cancer.
Infants and young children are at greatest risk because they eat and drink more than
adults on a pound-for-pound basis. In this way, they have a greater exposure to BPA,
says the National Institute of Environmental Health Sciences (NIEHS). Because of this
risk, the FDA has banned the use of SPA in baby bottles and sippy cups and is taking
steps to reduce human exposure to BPA. In 2009, the 6 largest manufacturers of baby
bottles vowed to stop selling polycarbonate versions in the United States.
Is BPA use common?
Polycarbonate plastic is found almost everywhere in modern life, and BPA is one of
the highest-volume chemicals produced worldwide. Polycarbonate plastic has proved
a handy substitute for glass and ceramic containers. Glass and ceramic can break or
can be difficult to clean. Polycarbonate plastic bottles can be sterilized easily
and don't soak up odors. As a resin, polycarbonate lines the insides of most canned
foods. This includes baby formula.
Other types of plastics are also used as food and beverage containers. You can tell
one plastic from another by the recycling triangle stamped on the container (usually
on the bottom). Polycarbonate usually containers carry a No. 7.
What's the problem?
In a 2003-04 health survey, the CDC made a surprising discovery: It found BPA in the
urine of nearly 93% of the more than 2,500 people tested. The survey evaluated children
6 years of age and older, teens, and adults. Females had significantly higher levels
of BPA than did males. Children had the highest levels.
Most people are exposed to BPA through foods and beverages, according to the NIEHS.
It is also found in air, dust, and ground and surface water.
BPA ends up in foods and beverages because it leaks from containers and can linings.
Certain foods, as well as heat, appear to speed up this leaking, the NIEHS says.
A number of studies suggest a link between BPA exposure at a young age and certain
health problems. Animal studies have shown that BPA at levels typical in the environment
acts like estrogen on breast, ovarian, and prostate tissue. Some researchers point
to a possible connection between BPA and obesity, diabetes, and cardiovascular disease.
Based on a review of the published studies, the NIEHS says it has "some concern" about
the health effects of BPA on fetuses, infants, and young children. BPA does not appear
to cause birth defects, but it may cause neural and behavioral effects, it says. Adults
who are not exposed to BPA at work do not appear to be at risk for reproductive system
The study results are based on animal research. This may be difficult to apply to
people, the NIEHS says, but the possibility that BPA may change human development must
be considered. More research is needed to measure the effects of exposure on human
What can you do to lower BPA exposure?
While scientists debate the issue, you can take steps to reduce your family's exposure
Here are suggestions from the NIEHS:
Avoid polycarbonate containers that contain BPA. They usually have a No. 7, and
sometimes a No. 3, stamped on the bottom.
If you do use polycarbonate containers, don't put them in the microwave. When
heated, the plastic may break down over time.
When possible, use fresh or frozen foods instead of canned foods.
Choose glass, porcelain, and stainless steel containers instead of plastic. This
is especially important for foods or beverages that are hot.
Use baby bottles and sippy cups that aren’t made with BPA.
Please consult your health care provider with any questions or concerns you may have
regarding this condition.