# Foul foil

**URL:** <https://boards.straightdope.com/t/foul-foil/135582>\
**Category:** Cecil's Columns/Staff Reports\
**Created:** [November 6, 2002, 5:49pm UTC](https://boards.straightdope.com/t/foul-foil/135582 "2002-11-06T17:49:48Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![MyOld85MG](https://avatars.discourse-cdn.com/v4/letter/m/439d5e/32.png) [@MyOld85MG](https://boards.straightdope.com/u/MyOld85MG)\
**Post date:** [November 6, 2002, 5:49pm UTC](https://boards.straightdope.com/t/foul-foil/135582/1 "2002-11-06T17:49:48Z")

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Re: “classic column”

[http://www.straightdope.com/classics/a1\_121a.html](http://www.straightdope.com/classics/a1_121a.html)

What I want to know is, is it safe to eat the “grayish-black mush of aluminum oxide” that results when aluminum foil surrenders its electrons to ketchup?

(Naturally, this leads into the questions: Is it safe to eat x amount of aluminum? Is it safe to cook in aluminum pots and pans?)

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**Author:** ![bibliophage](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bibliophage/32/7615_2.png) [@bibliophage](https://boards.straightdope.com/u/bibliophage)\
**Post date:** [November 7, 2002, 3:41am UTC](https://boards.straightdope.com/t/foul-foil/135582/2 "2002-11-07T03:41:29Z")

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Cecil has discussed the health consequences of aluminum a couple of times, most recently in [What’s the latest on the link between aluminum and Alzheimer’s disease?"](http://www.straightdope.com/classics/a971219.html)

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**Author:** ![Irishman](https://avatars.discourse-cdn.com/v4/letter/i/b487fb/32.png) [@Irishman](https://boards.straightdope.com/u/Irishman)\
**Post date:** [November 7, 2002, 4:36am UTC](https://boards.straightdope.com/t/foul-foil/135582/3 "2002-11-07T04:36:05Z")

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Minute traces of aluminum oxide are probably not important. On the other hand, I probably wouldn’t eat a big lump of the stuff in the ketchup, if nothing else for aesthetic reasons. It probably won’t kill you, but it might not be that tasty either. And why risk it?

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**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\
**Post date:** [November 7, 2002, 6:37pm UTC](https://boards.straightdope.com/t/foul-foil/135582/4 "2002-11-07T18:37:08Z")

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There’s a chance that reduced (elemental) aluminum might be harmful, but if aluminum oxide were poisonous, we’d all be dead by now. Aluminum is the third most abundant element in the Earth’s crust, appearing primarily in its oxide form, so the stuff’s all over the place. And it’s very difficult to get elemental aluminum from the oxide, so there’s no real risk of your body separating out the (possibly) harmful element.

But it is certainly gross.