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Tin foil

  1. Oct 2, 2009 #1
    My roommates were using Tin Foil under the stove burner to prevent the base from getting messy.

    One instance when I was cooking soup, the contents spilled onto the base covered by the tin foil. The contents started to burn and I saw flames.

    Tin foil has a very high melting point. I can't remember if I saw a hole in the tin foil but it definitely looked like the foil burned.

    In either case, I need to establish the conclusion whether or not this poses a health hazard as a result of the burning tin foil and whether the tin foil in the stove top poses a fire hazard.

    My roommate argued that because the base and the foil are both metals, the contents that spilt would have burned anyway. This is soup that we're talking about and I don't think the contents would have burned if they foil had not been there.


    Thank you!
     
  2. jcsd
  3. Oct 2, 2009 #2

    Borek

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    Tin foil is actually aluminum and is generally not considered hazardous for the health.

    As for the fire hazard - my bet is that flames you have seen are not related to foil and you would see them even if there was no foil. Foil gets easily and fast oxidized in flame, but amount of Al is small and amount of additional heat generated during oxidation is neglectable compared to the heat from burning gas (that is during soup cooking, not in some fancy setups designed to exploit Al oxidation - after all termite uses exactly the same reaction, but amount of Al involved is incomparable).

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    methods
     
    Last edited: Oct 2, 2009
  4. Oct 2, 2009 #3
    Sorry, what are you trying to say here?
     
  5. Oct 2, 2009 #4

    mgb_phys

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    Al foil can burn (oxidise), but only very slightly on the surface and it is nothing compared to the burning soup
     
  6. Oct 2, 2009 #5
    My roommate tried to argue with me saying that tin foil cannot burn. In theory it can start to melt at very high temperature. And based on the above response, it can burn but very slightly.

    I guess I should have made myself clear.

    So Tin foil does not pose a health risk if burned? I thought it would be toxic like plastic.
     
  7. Oct 2, 2009 #6
    The amount that you could burn on a stove isn't hazardous. You definitely don't want to stand over it and inhale it when it's burning, but if that worries you, just open a window or something. Aluminum can have some pretty toxic effects on the nervous system, but these occur with much higher quantities than what you're talking about. What seems to be a bigger problem to me is that your stove is getting hot enough to oxidize a significant amount of aluminum.
     
  8. Oct 2, 2009 #7

    chemisttree

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    This is probably not an aluminum fire. You probably burned the soup solids which contains a lot of NaCl and other ash producing materials. The ash from the fire likely contained Na2O or NaOH or Na2CO3 which is very corrosive to aluminum, especially at elevated temperature.
    Burned a hole? No.
    Corroded a hole from exposure to alkaline ash and high temperature? Very probable.
     
  9. Oct 2, 2009 #8

    DaveC426913

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    Look at it this way: the tin foil is protecting everything else from harm.

    Of all the things that could get dripped on and burned, tin foil is probably a good idea safety-wise. Better than rubber or plastic or some other unpredictable thing being set ablaze.
     
  10. Oct 2, 2009 #9
    pzona and chemisttree thank you! Now my roommate was rather condenscending about it, do know of a scientific article which I just post on the stove? I was really pissed off yesturday.
     
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