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Mixing household bleach with urine

  1. Apr 30, 2007 #1
    Hello everyone,

    Not that I looking to experiment or anything, but anyway...correct me if I'm wrong anywhere here...please.

    An associate of mine was wondering how to get rid of cat urine smell. Having exhausted all attempts to cover it up or use that enzyme stuff, I told him I usually treat the offending area(because I have 3 cats, I know)with a solution of household bleach. The ensuing reaction liberates alot of chlorine gas and that he should leave the area for a short time as chlorine gas is very irritating. (I do this all the time, and my kitties love me)
    A friend strongly advised him not to mix bleach with urine because urine has ammonia in it. And the gas is toxic and will kill you.

    Well first off I don't think urine has ammonia in it because urine is acidic. (Uric acid). The ammonia you smell from a cat's litter box is from the decomposition of the nitrogen rich by-products of metabolism. Correct so far?

    Secondly the gas is chlorine because sodium hypochlorite is an oxidizer and it gives up it's oxygen in the process and liberates chlorine as a by-product.

    Third the reaction is also somewhat of a typical acid-base reaction because bleach has a high ph and urine has a low ph.

    I don't think I'm too far off base with the description of the reaction, or the origin of that ammonia smell, am I??
    Please someone correct me if I'm wrong.

    Also just out of curiosity, what would be the final products of a reaction with an oxidizer like sodium hypochlorite and uric acid and urea?
    Carbon dioxide, water, sodium chloride. hmmmmm...where does all that nitrogen go??

    Also what would the result of mixing ammonia and bleach? Hmmmm...?
    I know it doesn't smell good, but do they even react?

    Thanx for looking

  2. jcsd
  3. Apr 30, 2007 #2


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    You're kidding, right? You should immediately Google on "ammonia and bleach" for your own safety.
  4. Apr 30, 2007 #3
    I figured chloramines were one of them. No, I have never mixed bleach and ammonia intentionally. Only accidentally once then immediately poured out he mix because like I said it didn't smell good.

    Just mainly wondering about the danger of using a mild bleach solution to clean up after a cat?
  5. Apr 30, 2007 #4
    there is probably no harm in cleaning up cat urine with bleach. i've worked with stuff like pure chlorine gas before and accidently breathed some in, but I am fine.Just work in a ventilated area in and you will be ok.
  6. Jul 1, 2007 #5
    Mixing bleach and ammonia can be extremely dangerous

    Per a quick Google search to verify:

    There are several ways household ammonia and bleach can react. All of them are dangerous.

    Reaction type 1: Ammonia directly reacts with bleach to form hydrazine (N2H4, which, in addition to being extremely poisonous, can burn even in the absence of air! It explodes on contact with rust!

    2NH3 + NaOCl -----> N2H4 + NaCl + H2O

    Reaction type 2: Bleach hydrolyzes into sodium hydroxide and hypochlorous acid, which in turn decompose into chlorine gas and nascent oxygen (both poisonous). The chlorine gas in turn reacts with the ammonia to form chloramines, also very poisonous.

    NaOCl -----> NaOH + HOCl
    HOCl ---> HCl + O (monatomic oxygen)
    NaOCl + 2HCl -----> Cl2 + NaCl + H2O
    2NH3 + Cl2 -------> 2NH2Cl (chloramine)
    4NH3 + 2Cl2 ------> 2NHCl2 (dichloramine)
    6NH3 + 3Cl2 ------> NCl3 (trichloramine or nitrogen trichloride)

    {some of these chemicals have effects similar to phosgene gas on lung tissue and other mucous membranes}
  7. Jul 11, 2007 #6
    You once mixed ammonia and hypochlorite "accidently"? You really need to pay more attention to what you're doing. Not only are chloramine gases very toxic, trichloramine is a contact explosive. If anyone here has ever observed Nitrogen triiodide, you'll know exactly how dangerous this is.
  8. Jul 11, 2007 #7
    Yes, a household member of mine (don't want to mention any names) dispensed regular household ammonia into an empty spray bottle (for cleaning)labeled "bleach". I know, not good.
    Well I dispensed what I thought was bleach into what I knew was bleach, then proceeded to dump the mixture out when I noticed something wasn't right.
    This family member was immediatly instructed on the error of their ways.

    I know about nitrogen triiodide. I made it once in high school. It has no practical purpose at all.

    Thank you for all the advice everyone. I'm usually pretty careful, but I will be more carefull in the future.

  9. Aug 8, 2007 #8
    Actually, humans and mammals excrete urea (not uric acid) in their urine. Birds usually excrete uric acid.

    Urea is CO(NH2)2 (a structure analogous to acetone).
  10. Aug 10, 2007 #9


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    Not much of a chemistry answer, but try using Borax.
  11. Aug 10, 2007 #10
    Hmmmmm....Borax, or sodium borate I beleive. What would be the reaction there?

  12. Aug 10, 2007 #11


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    So basically it's like Oxyclean.
  13. Aug 13, 2007 #12
    I highly doubt that chlorine is released, its simply to reactive and its saying that NaOH is formed.... Wrong!
    NaOCl does give up its oxygen but it makes NaCl, salt...

    however dangerous chemicals are going to form, but for the small amount of urea that is in urine... i wouldn't worry about it!
    even if your exposed to dangerous levels i'm sure you can heal because chlorine and i imagine similar chemicals do not leave long term effects
  14. Aug 13, 2007 #13
    I'm sorry. I guess I was wrong then.

    Just the gas released when I squirt bleach solution to clean up after kitty smells an awful lot like chlorine, because I thought the uric acid in the urine was reacting with the hypochlorite to give off chlorine in some way.

    I know urine eventually contains ammonia.

    But does fresh urine actually contain ammonia?

    Is urine acidic or basic?


  15. Aug 13, 2007 #14
    fresh urine does not contain much ammonia due to the acidic condition of urine, you can usually tell by the smell, but the enzymes in the urine break down the urea to CO2 and ammonia over time, but if the conditions are changed to slightly basic, like with sodium bicarbonate, the production will be much quicker, unless you use a highly basic chemical like NaOH as it will denature the enzymes and possibly get rid of the smell, or prevent the smell, after that try a scented detergent.
    I am not so sure about the bleach, but if it works, have good ventilation.
  16. Aug 22, 2007 #15
    It works real good.

    But if there is an excess (of old urine), you best be hoping you're on your way out of there.

  17. Sep 22, 2007 #16
    I personally encountered the bleach/ammonia reaction when a hospital floor had to be evacuated in 1965. I believe that the same phenomenon was the cause of the Riverview Hospital (CA) emergency room incident in 1993 (bleach/urine reaction), the cause of which was never officially proven, and chloramine was never even considered by two investigative bodies.
  18. Dec 5, 2007 #17
    Hey. Isn't urine alkaline and NOT acidic ?! Urine contains urea, uric acid and creatinine, with water and mineral salts as its main constituents.

    I do remember peeing on universal pH-paper when i was 13 (HAHA)..it registered pH 9 = alkaline.
  19. Dec 6, 2007 #18
    The reaction is between sodium hypochlorite and ammonia. Acidity is not required. The alkaline ammonia is a breakdown product of urea.
  20. Dec 8, 2007 #19
    I don't think it's correct; I think the author intended "perborate" not borax: borax is higly inert.
  21. Dec 8, 2007 #20
    Urine can contain ammonia, just for the reason you say, especially if you have some bacterial sepsi; the more urine is kept in vesica, the more ammonia forms. However urine contains urea, more than ammonia, and urea gives with bleach a similar reaction (of bleach/ammonia) so it generates chloramines and chlorine.
    Last edited: Dec 8, 2007
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