Use of plastics in cooking and food storage can carry health risks, especially when hormone-disrupting chemicals from some plastics leach into foods and beverages. Many petroleum-based chemicals go into the manufacture of plastics.  Some can leach into food and drinks and possibly impact human health.  Leaching increases when plastic comes in contact with oily or fatty foods, during heating,  and from old or scratched plastic.  I had one migraine patient who traced her migraines to eating salad dressing she had brought to work in an old yogurt container.  Types of plastics shown to leach toxic chemicals are polycarbonate, PVC and styrene. 

Fetuses and young children are at greatest risk. Young children’s immature immune systems, rapid development and different eating patterns make them more vulnerable to toxic exposures. Long term exposures to these chemicals or a few large exposures at a critical time in development could adversely impact children’s health.

Bisphenol A (BPA) is a chemical that mimics the action of the human hormone estrogen which can leach from polycarbonate plastic.  Human exposure to BPA is widespread, at levels high enough to cause biological effects.   Scientists have measured BPA in the urine of 95% of adults, in the blood of pregnant women, in umbilical cord blood and in the placenta, all at levels demonstrated in animals to alter development.

Bisphenol A has been found to stimulate prostate cancer cells and causes breast tissue changes in mice that resemble early stages of breast cancer in both mice and humans as well as increasing the susceptibility of prostate tissue to carcinogenesis. One study found an association between ovarian dysfunction and higher levels of BPA in urine.  Early-life exposure to BPA can also cause genetic damage.  Researchers found that BPA causes chromosomal errors at low levels of exposure in mice, which can lead to spontaneous miscarriages and birth defects.  One study found that women with a history of recurrent miscarriages had over threefold higher levels of BPA in their blood compared to women without a miscarriage history.
Other adverse effects include altered reproductive function, including:

* Early onset of puberty, and stimulation of mammary gland development in female animals
* Changes in hormones, including decreased testosterone
* Increased prostate size, decreased sperm production
* Altered immune function
* Behavioral effects including hyperactivity, increased aggressiveness, impaired learning and other changes in behavior
* Association of high levels of BpA with increased risk of diabetes and heart disease in adults.

DEHA (di(2-ethylhexyl)adipate) is one of several plasticizers (softeners) to which people have daily exposure through food, water, air and consumer products. PVC cling wrap contains DEHA, which can leach into oily foods on contact and when heated. DEHA exposure in a developing animal is linked to negative effects on the liver, kidney, spleen, bone formation and body weight. It is also a possible human carcinogen, affecting the liver.

Styrene can leach from polystyrene plastic.  Styrene is toxic to the brain and nervous system, among workers with longer-term exposures, but also has been found to harm red blood cells, liver, kidneys and stomach in animal studies.  Aside from exposure from food containers, children can be exposed to styrene from secondhand cigarette smoke, off-gassing of building materials, auto exhaust fumes and drinking water.

PVC: The toxic plastic
Polyvinyl chloride, also known as vinyl or PVC, poses risks to both the environment and human health. PVC is also the least recyclable plastic.
• Vinyl chloride workers face elevated risk of liver cancer.
• Vinyl chloride manufacturing creates air and water pollution near the factories, often located in low-income neighborhoods.
• PVC needs additives and stabilizers to make it useable. For example, lead is often added for strength, while plasticizers are added for flexibility. These toxic additives contribute to further pollution and human exposure.
• Dioxin in air emissions from PVC manufacturing and disposal or from incineration of PVC products settles on grasslands and accumulates in meat and dairy products and ultimately in human tissue. Dioxin is known to cause cancer. Low-level exposures are associated with decreased birth weight, learning and behavior problems in children, suppressed immune function and disruption of hormones in the body.

Tips for safer, more sustainable food use of plastics

1. Avoid using plastic containers in the microwave. Since chemicals are released from plastic when heated, it’s safest not to microwave food and drinks in plastic containers. Instead use glass or ceramic containers free of metallic paint.
2. Especially avoid using plastics for fatty foods, as there is greater leaching of chemicals into fatty foods.
3. Beware of cling wraps, especially for microwave use. Instead use waxed paper or paper towel for covering foods. If you do use plastic, don’t let the plastic touch the food. For plastic-wrapped deli foods, slice off a thin layer where the food came in contact with the plastic and re-wrap in non-PVC plastic wrap or place in a container.
4. Use alternatives to plastic packaging whenever possible. Use refillable containers at your grocery store. Bring your own take-home containers to restaurants. Bring reusable bags or cardboard boxes to the grocery store.
5. Avoid plastic bottled water unless you’re traveling or live in an area where the quality of water is questionable. Bottled water, because it is less regulated, has less-certain purity and safety than tap water, and is much more expensive. If you’re worried about tap water quality, consider installing a home water filter or use an inexpensive filter pitcher.
6. If you do use plastic water bottles, take precautions. If you use a polycarbonate water bottle, to reduce leaching of BPA, do not use for warm or hot liquids and discard old or scratched bottles. Water bottles from #1 or #2 plastics are recommended for single use only. For all types of plastic, you can reduce bacterial contamination by thoroughly washing daily. However, avoid using harsh detergents that can break down the plastic and increase chemical leaching.
7. Baby bottles. Use alternatives to polycarbonate plastic baby bottles and “sippy” cups. (See below) Knowing what we do about BPA leaching and the real risks to children’s health, you might be surprised to learn that most plastic baby bottles and many “training” or “sippy” cups are made of polycarbonate. Fortunately there are alternatives, including baby bottles made of glass, polyethylene or polypropylene. Those made of pliable, milky-colored plastic contain no polycarbonates. Usually baby bottles are not labeled, so if you have questions about the type of plastic used, call the company’s toll-free number listed on the package.
8. Minimize leaching of BPA from polycarbonate baby bottles. If you can’t avoid use of polycarbonates-for example, if it’s the only bottle your baby will take-then just follow these tips:
• Discard old, scratched polycarbonate baby bottles and “sippy” cups. Plastic that shows signs of wear-such as scratches or a cloudy, crackled appearance-more readily leaches chemicals. Scratches can also harbor bacteria.
• Heat foods and drinks outside of the plastic and then transfer into the plastic only after they are cool enough to eat or drink.

More on baby bottles and “sippy” cups
Avoid: Polycarbonate product examples
• Bottles: Avent; Dr. Brown’s; Evenflo (clear); First Years; Playtex Vent Aire; Sassy; TupperCare
• “Sippy” cups: Gerber Suzy’s Zoo & Sippy Snacker; Gerber Soft Starter
Safer alternatives: Non- polycarbonate product examples
• Bottles: Evenflo glass or pastel polyethylene plastic; Gerber polypropylene opaque plastic; Medela breastmilk polypropylene storage bottles and polyethylene milk storage bags; disposable bottle systems with polyethylene plastic inserts (e.g., Playtex Nurser, Playtex Drop-Ins)
• “Sippy” cups made of polypropylene or polyethylene: Avent Magic Cup; Evenflo cups (inner lining); First Years Take & Toss; Gerber Color Change, Sport Fun Grip; Playtex Sipster, Big Sipster & Quick Straw
Baby bottle nipples are usually made of silicone or latex rubber. Silicone nipples are lighter in color and are safer, as latex rubber nipples may leach carcinogenic nitrosamines.