It appears that in the last couple of years a plastic-phobia has been spreading like a wildfire. As a gastroenterologist and an expert in the field of nutrition, people often ask me about my views on plastic containers being used for food and water. I confess it can be confusing.

There are numbers in little triangles under plastic-ware, and even though I know they mean something, I have to look it up every time! So how is the average consumer supposed to know what to do? Is it safe to drink water from those bottles? What about milk? And let’s not even talk about baby bottles because everyone gets emotional, but rightfully so, since fetuses and infants are at a higher risk because their organs are still developing.

If you look into this a little deeper, it seems people have been trying to call attention to this problem for at least ten years if not longer. A researcher at the University of Missouri reported on BPA (bisphenol-A) having a resemblance to human estrogen, and its possible harmful effects on humans. Between 2005 and 2007, scientific publications were publicized in news media leading to heightened awareness and concern amongst people everywhere. I read that 92 percent of government-sponsored studies showed that certain plastics generated harmful levels of toxins in animals, humans and even in the placenta; however, I was not surprised by the fact that none of the studies sponsored by the plastic industry showed there was any cause for concern.

There is a common theme though, and some specific byproducts of some plastics have been identified as toxic. Not all plastic containers are created equally bad. Let us run the numbers.

Plastics that are NOT good:
#3 – PVC or polyvinyl chloride. Also called ‘the poison plastic’. Workers in PVC plants have a higher risk of liver cancer. Stabilizers used may contain lead. Fumes from production plants or incineration contain dioxin, a known carcinogen, which in low doses can cause learning and behavioral problems in children. In some kinds of cling wraps, squeeze bottles, cooking oil and peanut butter containers; also some plastic toys and building blocks.  This one is best avoided. Definitely not for heating food!

#6 – Polystyrene. Toxic to the brain and nervous system in workers with long-term exposure; also to many internal organs in animals. In ‘Styrofoam’ trays, cups, bowls, egg cartons and opaque plastic cutlery. As long as hot food that you are eating is not in contact, (e.g., egg cartons, trays) you are safe. ‘Styrofoam’ containers are really made of polystyrene. Small amounts of styrene leaches into hot foods, especially fatty or acidic foods. Choose paper-cups and containers where possible. Opt for ceramic mugs for your coffee. An occasional cup of coffee is not a problem since the risk is when the toxin accumulates over a long period of time in your body. If you get home food in a foam container, transfer it into glass or ceramic as soon as you get home. And never microwave food in polystyrene containers.

Plastics that are Safer:
#1 – PETE (Polyethylene terephthalate ethylene). In soda, juice and water bottles, and some peanut butter containers. The data about toxicity if this material is very weak, but questions have been raised. Best to use the bottles and throw them away. They are not advisable for reuse.

#2 – HDPE (High density polyethylene). In opaque milk and water jugs. Again considered safe but not for reuse.

#4 – LDPE (Low density polyethylene). In grocery bags, Ziplock bags, plastic wraps, some bottles. Also relatively safe. However, if you are reheating food with a plastic wrap cover, it is best not to let the food directly come in contact with the wrap, especially fatty foods.

#5 – Polypropylene. In Rubbermaid, yogurt, syrup and deli/carryout containers; straws and baby bottles. As long as food is not heated in these, and especially not in a microwave, storage of cooled foods is fine.

And the mixed bag that is #7!
#7 – Used to be the bad BPA-containing polycarbonate. Polycarbonate is found in the plastic lining inside soup and other cans. BPA has a hormonal effect and has been implicated in prostate cancer and early breast tissue changes resembling cancer. In fetuses, genetic/ chromosomal problems may arise leading to miscarriages and birth defects. But now #7 is used for ‘other,’ which means items that cannot be classified in numbers 1 to 6. If it says ‘7-PC’, then it is bad and should be avoided. ‘7-PLA’ is made from corn, and other #7’s can actually be fine. If in doubt, we are advised to call the manufacturer. BPA-free baby bottles are also classified under #7, just to make it even more confusing! Nalgene and Camelbak water bottles are classified here, too.

Most of the data we have comes from animal experiments, actual problems in humans have not been documented. As always, the whole point is just to be careful – why take a risk if it can be avoided? But occasional exposure cannot be helped, and there is really no cause for alarm.

Basic Tips:

•    Plastics and hot food do not mix. Cool food before storing in plastic containers.
•    Plastics and microwaves do not mix. Heat food in glass or ceramic containers, or on the stove top.
•    Polycarbonate (BPA) and the bad plastics are to be avoided, especially with infants and children.
•    Old scratched plastic containers will leach more toxins into your food especially when heated.
•    Avoid cling wraps that have PVC.
•    Avoid canned foods, especially if acidic, and never heat soup in a can.
•    Dishwasher- and microwave-safe plastics are ‘safe’ because they will not crack, break or get damaged; they could still harm you.
•    Do not reuse commercial water and juice bottles.
•    Read the numbers under baby bottles and sippy cups. Do not heat milk in them.
•    But, most importantly, do not panic. Educate yourself and make smart choices, and you will be safe. Remember, there are many worse things in our environment and occasional small exposures will not hurt you.
•    Styrofoam is safest when items are not hot or heated.

References:

1.    Institute for Agriculture and Trade Policy, Smart Plastics Guide. www.iatp.org
2.    vom Saal FS, Myers JP. Bisphenol A and risk of metabolic disorders. JAMA 300(11):1353-55. Online Sept 16,2008.
3.    http://www.grinningplanet.com/2008/04-08/foam-cups-polystyrene-cups-article.htm

|