# Is my lunch killing me???

**URL:** <https://boards.straightdope.com/t/is-my-lunch-killing-me/187160>\
**Category:** Factual Questions\
**Created:** [July 9, 2003, 4:14am UTC](https://boards.straightdope.com/t/is-my-lunch-killing-me/187160 "2003-07-09T04:14:22Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Mukluk](https://avatars.discourse-cdn.com/v4/letter/m/b77776/32.png) [@Mukluk](https://boards.straightdope.com/u/Mukluk)\
**Post date:** [July 9, 2003, 4:14am UTC](https://boards.straightdope.com/t/is-my-lunch-killing-me/187160/1 "2003-07-09T04:14:22Z")

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I’ve heard that heating leftovers in plastic containers is dangerous, particularly for men. Something about some chemical released into the food can trick the body into some kind of hormonal imbalance that can lead to some types of cancer. Is this _another_ thing to watch out for or is it nonsense?

If it is a problem, are some kinds of plastics OK? What about those reuseable/disposable containers sold in grocery stores? (In Canada as Glad or Ziplock brands) What about Tupperware containers? Is it back to sandwiches for Mukluk?

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**Author:** ![Tarantula](https://avatars.discourse-cdn.com/v4/letter/t/e274bd/32.png) [@Tarantula](https://boards.straightdope.com/u/Tarantula)\
**Post date:** [July 9, 2003, 7:47am UTC](https://boards.straightdope.com/t/is-my-lunch-killing-me/187160/2 "2003-07-09T07:47:06Z")

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Heating things in plastic containers is generally a bad idea. Chemicals from some plastics can migrate into the foodsuff and start doing their thing… not good.

If you must heat food in a plastic container - use “food grade” plastic. This will be clearly marked, and should be accompanied by some mark of authority (such as a BS number, in the UK).

That’s all folks !

Hope it helps…

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**Author:** ![Blake](https://avatars.discourse-cdn.com/v4/letter/b/a9a28c/32.png) [@Blake](https://boards.straightdope.com/u/Blake)\
**Post date:** [July 9, 2003, 7:58am UTC](https://boards.straightdope.com/t/is-my-lunch-killing-me/187160/3 "2003-07-09T07:58:23Z")

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Basically what Tarantula said. if it isn’t clearly marked :microwave safe" of similar then reheating is a no go.

The biggest problem is that most plastics used to be polyethylene, which isn’t entirely waterproof, coated with PVS to make them waterproof. PVC, when it is heated or subjected to microwaves breaks down into the component vinyl chloride monomers. Vinyl chloride is a fairly potent carciniogen.

These days it’s less common to produce PVC and PVC coated products for a range of reasons, but they are still out there and still just as dangerous. AFAIK all Tupperware is now microwave safe, but even if that is the case in the past they conatined PVC and it’s hard to know how old they are.

I don’t know why this would affect men more than women. AFAIK the biggest danger form ingesting vinyl chloride remains liver cancer, and women have got those as well as men.