# Aluminum foil leaching out when thawing food **URL:** \ **Category:** Factual Questions\ **Created:** [April 9, 2016, 8:23pm UTC](https://boards.straightdope.com/t/aluminum-foil-leaching-out-when-thawing-food/751698 "2016-04-09T20:23:41Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![Velocity](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/velocity/32/18006_2.png) [@Velocity](https://boards.straightdope.com/u/Velocity)\ **Post date:** [April 9, 2016, 8:23pm UTC](https://boards.straightdope.com/t/aluminum-foil-leaching-out-when-thawing-food/751698/1 "2016-04-09T20:23:41Z")
Supposedly, while refrigerating food in aluminum foil is OK, freezing and thawing it in aluminum foil is not, because the thawing process can cause aluminum to begin leaching into the food? Is it that moisture condenses while the foil and food is thawing, and some dissolved aluminum leaches out? But if aluminum leaches out that easily, you’d expect acidic or salty foods to leach it as well ---
**Author:** ![TipTapTwo](https://avatars.discourse-cdn.com/v4/letter/t/34f0e0/32.png) [@TipTapTwo](https://boards.straightdope.com/u/TipTapTwo)\ **Post date:** [April 10, 2016, 12:11am UTC](https://boards.straightdope.com/t/aluminum-foil-leaching-out-when-thawing-food/751698/2 "2016-04-10T00:11:23Z")
Here have a 2012 paper ( PDF file) from the _International Journal of Electrochemical Science_ entitled Risk Assessment in Using Aluminum Foil in Food Preparation [www.electrochemsci.org/papers/vol7/7054498.pdf](http://www.electrochemsci.org/papers/vol7/7054498.pdf) Appearantly you are correct Velocity, that acidic/salty things like salsa inherently corrode/leach aluminum onto the food. The paper even finds that general spices and tap water increase Al leaching significantly. The paper really only tests for cooking, like say for putting aluminum over your oven roast, or for steaming. But I would say, based on the paper (everyone should really read it, it is very interesting and it even goes into the health risks of ingesting too much aluminum a bit at the start) that even packing your leftovers and leaving them in the fridge (where the spices and the moisture can act to leach out more Al over several days) would be unwise. ---
**Author:** ![Senegoid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/senegoid/32/6606_2.png) [@Senegoid](https://boards.straightdope.com/u/Senegoid)\ **Post date:** [April 10, 2016, 1:42am UTC](https://boards.straightdope.com/t/aluminum-foil-leaching-out-when-thawing-food/751698/3 "2016-04-10T01:42:02Z")
So, can you give us a summary of how dangerous it is to eat aluminum? How toxic is it? ---
**Author:** ![TipTapTwo](https://avatars.discourse-cdn.com/v4/letter/t/34f0e0/32.png) [@TipTapTwo](https://boards.straightdope.com/u/TipTapTwo)\ **Post date:** [April 10, 2016, 3:08am UTC](https://boards.straightdope.com/t/aluminum-foil-leaching-out-when-thawing-food/751698/4 "2016-04-10T03:08:28Z")
Ok Senegoid, I can give a few choice quotes from a variety of peer reviewed journals/sources; but if anyone really wants to know more than just soundbytes then they really should read the links themselves. Toxnet Toxicology data network - National Library of Medicine HSDB Database [http://toxnet.nlm.nih.gov/cgi-bin/sis/search/a?dbs+hsdb:@term+@DOCNO+7331](http://toxnet.nlm.nih.gov/cgi-bin/sis/search/a?dbs+hsdb:@term+@DOCNO+7331) Agency for Toxic Substances and Diseae Registry > **[ToxFAQs™ - Letter A | Toxic Substance Portal | ATSDR](https://wwwn.cdc.gov/TSP/ToxFAQs/ToxFAQsLanding.aspx?id=190&tid=34)** > > The ATSDR ToxFAQs™ is a series of summaries about hazardous substances developed by the ATSDR Division of Toxicology. Information for this series is excerpted from the ATSDR Toxicological Profiles and Public Health Statements. Each fact sheet... Mount Sinai Hospital > **[Toxicology Health Information | Mount Sinai - New York](https://www.mountsinai.org/health-library/toxicology)** > > Toxicology is the study of the way chemical, physical, or biological agents negatively affect humans, animals, and the environment. Wikipedia (I know, but it cites good stuff in the footnotes) > **[Aluminium](https://en.wikipedia.org/wiki/Aluminium_poisoning#Health_concerns)** > > Aluminium (aluminum in North American English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals; about one-third that of steel. It has a great affinity towards oxygen, forming a protective layer of oxide on the surface when exposed to air. Aluminium visually resembles silver, both in its color and in its great ability to reflect light. It is soft, nonmagnetic and ductile. It has one stable isotope: 27Al, which is hi... Basically, you should only really worry about aluminum if you or a especially child (because Al gets taken up in still growing bones of children and causes bone diseases) have kidney problems like needing dialysis or are taking in long term IV nutrition, are working in a place with a bunch of Al in the air like in welding fumes (lung diseases), or are one of the few who are actually allergic to Al. Otherwise you should be fine living how you are. the toxicity levels are high enough to not care about (40mg per kilo of your mass per day) but with poorly functioning kidneys or breathing it in all the time at work, it adds up to the point that doctors recommend not using deoderant or antacids. From my above above post in the paper Risk Assessment in Using Aluminum Foil in Food Preparation they show that by grilling chicken in Al package, or by roasting in an oven with Al as a covering can increase the Al concentration of the meal anywhere between 76%-378% depending on the type of meat (red/white) and cooking preparation (using spices,tap water, acids, salt) which equals between 22.1 mg per person per meal ingested and 537.2 mg per person per meal. So if you have a child under 10 kilo in weight (22lbs) who has bad kidneys, (or even a child with good kidneys) cooking a beef roast with an Aluminum cover with tap water, salt, spices, and something acidic as a base for a sauce to cook it in would put the 10 kilogram child over his/her daily allowance of Al. ---
**Author:** ![TipTapTwo](https://avatars.discourse-cdn.com/v4/letter/t/34f0e0/32.png) [@TipTapTwo](https://boards.straightdope.com/u/TipTapTwo)\ **Post date:** [April 10, 2016, 3:52am UTC](https://boards.straightdope.com/t/aluminum-foil-leaching-out-when-thawing-food/751698/5 "2016-04-10T03:52:21Z")
Wow, I am sorry Senegoid for that apparent tone I took with you in my above post. After reading it back it sounds horrible. What I _was_ going for was excitement, a sharing of a new topic between friends. Like “hey, have you heard of a cartoon called Gravity Falls? Even if my anecdotes sound boring to you, you should still check it out. it is really well done.” Before Velocity’s post I never thought or cared about aluminum toxicity, and this same day research was enlightening because I have had kidney stones in the past and if I had known about this I would have been more careful, even though everything turned out fine anyway, no need to pile on more issues. So again, sorry for my tone of… not voice, if you had heard that everything would have been fine… but my tone of text. Thank you for showing me that I need to take my time and re-read my messages. ---
**Author:** ![Senegoid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/senegoid/32/6606_2.png) [@Senegoid](https://boards.straightdope.com/u/Senegoid)\ **Post date:** [April 10, 2016, 8:07am UTC](https://boards.straightdope.com/t/aluminum-foil-leaching-out-when-thawing-food/751698/6 "2016-04-10T08:07:29Z")
> [@TipTapTwo](#): > > Wow, I am sorry Senegoid for that apparent tone I took with you in my above post. After reading it back it sounds horrible. \< . . . \> Okay, no problem. Well, no big problem anyway. I only got _slightly_ //old-rolleyes// – but in the bigger picture, your post did address the question I asked. (Namely, for a brief TL;DR summary.) ETA: I see you’re new enough here that you probably don’t know what that “//old-rolleyes//” notation means. We used to have a “roll eyes” icon that was actually useful and meaningful, which then got changed to the useless and never-widely-accepted version we have now.