My son leaves pee in the toilet overnight but I am a light sleeper so he doesn’t flush. This leaves a unique smell in the toilet in the morning. Is there any safe chemical/tablet that could be put in the toilet after he pees so the smell/colour isn’t there in the morning?

  • $\begingroup$ No way to neutralize the smell without doing something drastic. The only thing that you might be able to do is mask the smell with some sort of automatic mechanical room deodorizer. So you have to decide what you want - stinky bathroom or good night's sleep? $\endgroup$
    – MaxW
    May 20, 2020 at 6:33
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    $\begingroup$ The smell is caused by bacteria which are feeding on urine. Regular cleaning of the toilet helps. $\endgroup$ May 20, 2020 at 6:40
  • $\begingroup$ Related posts that might be somewhat helpful: Storage of Urine; Can caustic soda (sodium hydroxide) be used to dissolve urine odour?. Long story short, you might want to prevent bacteria growth; asking your son to spray a disinfectant over the toilet bowl (once he's done) might do, but do make sure he understands the danger of chemicals often used as such (e.g. chlorates/peroxides). $\endgroup$
    – andselisk
    May 20, 2020 at 6:43
  • $\begingroup$ @imalipusram - ? She seems to be asking about the stink from a toilet bowl of urine left overnight. I assume that the son isn't spraying the whole toilet area with urine. $\endgroup$
    – MaxW
    May 20, 2020 at 6:58
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    $\begingroup$ You could try using an automatic toilet bowl cleaner tablet. These are placed in the tank (not the bowl), and release a cleaning agent into the water. I don't know if this would reduce the odor, but they're cheap enough (a few dollars) that it might be worth experimenting with a couple of different formulations to see if they help. Be careful when placing it into the tank -- the small amount of chemical released into the bowl with with each flush is relatively safe, but you want to avoid direct skin contact with the tablet itself. $\endgroup$
    – theorist
    May 20, 2020 at 8:13

1 Answer 1


With respect to available home remedies, do NOT use H2O2 or Oxiclean or a generic substitute containing Sodium percarbonate ($\ce{2 Na2CO3·3 H2O2}$).

The H2O2 may react with the urea forming even more problematic Urea Hydrogen Peroxide.

Also, avoid chlorine bleach (Sodium hypochlorite, NaOCl), as this creates problematic chloramine (NH2Cl) and potentially even more unstable (as in energetic) compounds.

My advice, use powdered charcoal dust from your outdoor grill, a safe and odor removing agent. The obvious downside is now your toilet will likely display black rings and require more cleaning (which is a positive in removing germs).

I will also make a statement with respect to exposure from interaction products between urea and carbon, no expected long term negative health consequences (as in possibly carcinogenic).

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    $\begingroup$ I think everything derailed $\endgroup$
    – Alchimista
    May 20, 2020 at 15:56

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