Plastic Wrap and Dioxin

I thought the plastic/dioxin thing died down a while ago. Apparently not. Perhaps you’ve seen the email forwarded to you, or maybe you’ve passed it on as well.
The one I got most recently had stuff like this:

*No plastics in micro
*No water bottles in freezer.
*No plastic wrap in micro

It purports to be from Johns Hopkins, and claims to be distributed to the Walter Reed Army Medical Center. Also cited in the email is a Dr. Edward Fujimoto from Castle hospital. It’s even says scary stuff like “drips poisonous toxins into the food”.

I love it.

But it’s a hoax. There’s some modicum of truth, but the noise is far greater than the signal. Still, as internet chain letters go, it’s reasonably interesting. The take-home message is that things that it’s not really something to worry about.

Only certain plastics can release dioxin. From the [dioxin homepage]: , “Dioxin is formed by burning chlorine-based chemical compounds with hydrocarbons.” Most household plastic wraps or plastic food containers do not contain chlorinated hydrocarbons. For example, polyethylene, polystyrene, and polypropylene, do not contain chlorine atoms. Polyvinyl chloride (PVC), on the other hand, does contain chlorine. Still, all these polymers are reasonably stable. Unless they burn, they probabaly won’t be releasing anything. Still, if you want to be extra extra careful, don’t heat polystyrene (because free styrene is toxic) or PVC (free chlorine is bad too).

It’s worth noting that most plastic wraps use non-chlorinated polymers (i.e. impossible to make dioxin). Saran wrap *used* to use PVC, but has since switched to something nonchlorinated. I read that Reynolds plastic wrap uses PVC, but I couldn’t get dig up any info for sure. Plastic wrap used by supermarkets or restaurants might be chlorinated. If you’re paranoid, avoid those, even though research hasn’t shown any dioxins ever getting to the food. The moral of the story is: don’t worry about plastic wrap, or just don’t microwave Reynolds or restaurant/deli wrap.

If there’s any danger, it might be from the plasticizers that are added to the plastics to make them more flexible. These are in PVC and polystyrene. They *probably* not be good for you, but at the levels you might get from them, it’s not really a concern unless you habitually incinerate them.

The frozen water bottle thing really has no basis in fact. There. Plastic people say that dioxins only form at temperatures above 700 Fahrenheit.

Have a look at these sites if you need more info.

[Microwave Ovens, Plastic wrap, and Dioxin]:’s take on plastic wraps and microwaves.

[American Plastics Council]: has some good info on [plastic food wrap safety]: and [plastics in microwaves]: and [freezing water bottles]: , but you should note that these pages are from the perspective of an industry group trying to allay public fears and worries, as well as preventing meltdown in their constituent companies.

[Which Plastics Are Safe for Lunchbox use]: has some good summary info on types of plastics and safety, but it’s somewhat paranoid.

For a discussion by concerned parents, you might check [Berkeley Parents Network: Advice about Microwaving]: . It’s really a good source of info, but the presentation is a little difficult to navigate since it’s discussion format.

[Glad]: and [Ziploc]: have both put up FAQs about how their products are safe, and their info seems less politically motivated and more sensical than the Plastics Council info.

I have a question. This is a psychological question. Is the email more credible because of the quote from Dr. Edward Fujimoto? How do you know he’s a medical doctor? Maybe he has a Ph.D. in English. If I told you I’m Dr. Hans Messermeister and I have degrees from Harvard and Yale, how does that make me a food expert, a health expert, or a chemistry expert? Maybe I got a degrees in English. Some quick digging shows that there *is* a Dr. Edward Fujimoto, but he’s a Ph.D, not a medical doctor, and he works at Castle medical center, not hospital, in Hawaii. Here’s a thought. Are people with Japanese names considered more credible than those with, say, more “local” sounding names?

Anyway, feel free to add comments or trackback to this if you have new/different info.

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