Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Types of flammable liquids

  1. Sep 4, 2003 #1
    There are certain types of flammable liquids which cannot be put out by water easily, i know of one, rocket fuel. but there are certain like components which make the fire worse? what are they? components which like when added with water make it worse.
    Last edited by a moderator: Feb 5, 2013
  2. jcsd
  3. Sep 4, 2003 #2


    User Avatar

    Well, as far as I know, the primary thing about flammable liquids and water is that the burning oil tends to just float on top of the water, so instead of cutting out it's oxygen supply, you simply spread it around.
  4. Sep 4, 2003 #3
    It all depends on the type of fire.

    The classic don't-use-water fires are cooking grease and electrical fires. Water on the former just splashes the flaming grease everywhere, the latter can electrocute you.

    Every fire is different.
  5. Sep 4, 2003 #4


    User Avatar
    Science Advisor

    It should also be added that water on the grease fire can be much worse than a simple case of "spreading the grease around", because it floats. I once saw a demonstration in which water was poured into a pot of burning grease. Because grease floats on water, the water immediately went straight to the bottom of the pot. Because the flashpoint of grease is much hotter than the boiling point of water, the water rapidly converted to steam as it reached the bottom. The resulting "geyser" shot the flaming grease high into the air, and far across the room.

    As for chemicals that cannot be doused by submersion, most of these are substances that contain their own oxygen supply (such as the rocket fuel you already mentioned).
  6. Sep 4, 2003 #5


    User Avatar
    Gold Member

    In some areas of hospitals that I have worked in, they have used halon to extinguish fires. We were trained that, if the halon dumps, get OUTTA THERE - as it completely removes the O2 from the air. How does this work? Anyone?
  7. Sep 4, 2003 #6
    http://www.harc.org/oha2.html [Broken]

    I always wondered.. would a fine mist of water work on a oil fire?
    Last edited by a moderator: May 1, 2017
  8. Sep 5, 2003 #7


    User Avatar
    Gold Member

    Thanks, Jikx. This is what the site said:
    "It stops the fuel, the ignition and the oxygen from dancing together by chemically reacting with them."

    I need a better explanation. What reacts with what?


    "Many people believe that halon displaces the air out of the area it is dispensed in. Wrong!"

    Interesting. Why would a Fire Safety course in a hospital give bad info? To be sure, I'm going to be making a couple of phone calls tomorrow!
  9. Sep 5, 2003 #8


    User Avatar



    I'm guessing that this is because the reactions of Halons with hydrogen containing compounds only occur at high temperatures.

    http://ehs.ucdavis.edu/sftynet/sn-55.html [Broken]

    Last edited by a moderator: May 1, 2017
  10. Sep 5, 2003 #9


    User Avatar
    Gold Member

    Last edited by a moderator: May 1, 2017
  11. Sep 7, 2003 #10
    (FZ+ Google Skills) > (Jikx Goodle Skills)

    hehe.. now that Tsunami's question has been answered, does anyone know if a fine mist of water will work on oil fires?
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook