Since You Asked: Plastics, germs could carry health risks in water bottles

We always keep at least a couple of bottles of water in our car when we're traveling, but rarely drink them, so they may be in the car for months before we drink them or toss them.

A friend says he read something about how the plastic in the bottle is not safe if it's left in a heated space over a period of time.

Are we putting ourselves in danger if we drink from those bottles after they've been sitting in the car for a month or two?

— William B.

Well, William, this time of year the only issue you'll face is trying to get that big chunk of ice past the tiny neck on the bottle (and we're assuming here that you're referring to recyclable, single-serving bottles sold in stores).

There is never a certainty in declaring something safe, and studies continue on the safety of using plastics with food or drink. One 2009 study in Germany suggested that polyethylene terephthalate, the plastic known as PET that's used in recyclable bottles, could leach a chemical into the water that could interfere with estrogen and other hormones. But the researchers said more studies would be needed to determine whether it posed a risk to humans.

For the record, the U.S. Food and Drug Administration has said the PET plastic poses no health threat when used to hold food. Any leaching that does occur is miniscule and not a health risk, the FDA claims.

It's important not to confuse your plastics, William. There have been numerous studies raising questions about the safety of using plastics containing bisphenol A (BPA), which were commonly used in such things as baby bottles, reusable sports water bottles and plastic toys. But that's not the plastic used in recyclable water bottles.

You can safeguard yourself against using BPA plastic by checking the recycling code on the plastic container. Inside a triangle on the plastic bottle, usually on the base, you'll find a number. In general, plastics that are marked with recycle codes 1, 2, 4, 5 or 6 are very unlikely to contain BPA. Plastics with numbers 3 or 7 may contain BPA.

There is a documented threat posed by all water bottles, however. It has nothing to do with the plastic and everything to do with plain ol' germs. Once you open a water bottle, and especially if you take a drink from it, you have introduced contaminants into a wet climate, causing those contaminants to get all giddy and reproduce like crazy.

So it's probably best not to let your water sit around for hours or days after it's been opened and then take a swig of it. Also, if you reuse a recyclable water bottle, make sure it's washed thoroughly. Nothing like a little warm puddle at the bottom of your bottle to create a germ factory.

Send questions to "Since You Asked," Mail Tribune Newsroom, P.O. Box 1108, Medford, OR 97501; by fax to 541-776-4376; or by e-mail to

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