Friday, June 6, 2008

Plastics rundown

Below is a quick rundown of the different plastics that are out there to help you better know what to avoid and what to look for:

Different types of plastic

Polyethylene - Containers for water, soft drinks, cleaners and detergents are made of it. There is high density and low density polyethylene. High density is an opaque plastic used for all kinds of bottles and some plastic bags, while low density polyethylene is used in grocery store bags, most plastic wraps and some bottles.

Polyvinyl chloride - It is used for various kinds of jars, bottles for cleaning fluids, some plastic squeeze bottles, and cling wrap. During manufacturing polyvinyl chloride (called PVC or vinyl), toxic chemicals such as Dioxin are released. Workers making PVC have a greater than average risk of liver cancer. When incinerated, PVC releases toxic airborne pollutants. These chemicals can then accumulate in meat and dairy products.

Polystyrene - Styrofoam food trays, egg cartons, disposable cups and plates, opaque plastic cutlery and take-out containers are made of polystyrene (PS). Styrene can leach from PS plastics. Studies on workers with long term exposure show that styrene can be toxic to the brain and nervous system. Animal studies also show adverse effects on various body organs.

Polypropylene - It is a cloudy plastic used for food containers, straws, yogurt cups, and baby bottles.

Polycarbonate - It is used heavily in baby bottles and sippy cups, water bottles, clear plastic cutlery and food can liners. It was chosen for baby bottles because it is transparent, hard, and shatterproof. Polycarbonate is made from Bisphenol A (BPA). In a study, released in 2008, it was shown that BPA, a synthetic sex-hormone that mimics estrogen, leaches out of baby bottles when they are heated. The leached amounts of BPA were similar to amounts or doses that were harmful in animal studies. The animals had changes in gender-specific behavior, altered immune function, decreased testosterone, impaired learning and they were also hyperactive and more aggressive.

How to be safe
Because plastics are so widespread, many plastic break-down products and toxic chemicals from plastics can be found in the blood and urine of most people. Infants and children are probably at greatest risk for harmful effects.Scientists disagree on the quantities of leached BPA that is safe. The European Food Safety Authority, for example, argues that rat and mice retain BPA much longer in their bloodstream than humans do. Humans eliminate BPA quickly in their urine. Large controlled studies are needed to definitely show that BPA is harmful in people. These kinds of studies may never be done because it is unethical to expose human beings to a potentially toxic chemical.

This is what you can do to eliminate or reduce BPA and other toxic chemicals from leaching into food:

Don't heat polycarbonate plastic containers. To find out if plastic is polycarbonate, look at the bottom of the container for an imprinted small triangle with the number 7 (a few newer non-polycarbonate plastics also have a 7).

Use plastic food containers made from polyethylene or polypropylene. They don't leach BPA. Imprinted bottom triangles have the numbers 1, 2, 4, or 5.Don't use cling wrap in the microwave.

Don't put plastic food containers or baby bottles in the dishwasher. Wash them by hand.Throw out old plastic containers. As plastic containers age, they release more chemicals.

Don't use scratched-up plastic containers. Again, damaged plastics may leak more chemicals.

Use glass or ceramic containers for heating in the microwave. Or better yet, don't use a microwave period. Who wants the molecular structure of their food changed by radiation?

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