Tuesday, January 11, 2011

Break the codes of plastic recycling

By David Burton
University Extension

Recycling numbers imprinted on the bottom of plastic containers have a special meaning and some should cause consumers pause, according to Tammy Roberts, nutrition and health education specialist, University of Missouri Extension.

“Most people know that there are numbers they need to use caution with but don’t know which ones,” said Roberts. “Recycling codes on the bottom of plastic containers can be any number between 1 and 7.”

The numbers actually indicate the type of plastic in the container. Here’s how it breaks down:

1: This is polyethylene terephthalate (called PET or PETE). Generally this is disposable water and soda bottles. It is generally safe but is porous so bacteria and flavors can accumulate so don’t re-use these containers.

2: High density polyethylene (HDPE) is considered safe and has low risk of leaching chemicals. Milk jugs, juice bottles, detergent and shampoo bottles are made of this.

3: Polyvinyl chloride (V or PVC) requires caution. There are phthalates which are softening chemicals that can interfere with hormonal development. PVC is used to make food wraps, bottles for cooking oil and plumbing pipes. “There are recommendations to minimize the use of this type of plastic around food. The risk is highest when containers start wearing out and are heated,” said Roberts.

4: Low density polyethylene (LDPE) is not considered to pose a risk. It is used to make cling wrap, grocery bags and sandwich bags.

5: Polypropylene (PP) is used to make yogurt containers and water bottles with a cloudy finish, medicine bottles, and straws. It is considered to be safe.

6: Polystyrene (PS) or Styrofoam is used to make disposable containers such as plates and cups. There is evidence that this type of plastic leaches potentially toxic chemicals. “It is important to avoid heating anything in these containers,” said Roberts.

7: This is all plastics invented after 1987 and they include polycarbonate which contains bisphenol A or BPA. Scientists believe BPA can act like the hormone estrogen. In animal studies estrogen has been linked to breast, prostate and other reproductive system problems as well as some cancers. Examples of some things made under this category include baby bottles some reusable water bottles and food containers that resist staining. It is important to note that not all plastics that have the number 7 contain BPA but the number 7 indicates that it could.

“Bottom line is that plastics that have a recycling code of 3, 6 or 7 should be used with caution especially with food or drinks. Be especially cautious with heat on plastics labeled with recycling code numbers 3 and 6,” said Roberts.

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