So, walk in the restroom to take a nice coffee-fueled leak.
Smells a little bleach-y. Nice. Lemme dirty it up.
Ahhhh.
Um…whew. My eyes and nose are burning. That doesn’t smell like bleach. Hm. Maybe I better hold my breath until I get done. Dammit, why did I fill up the BIG cup before I left home.
Escape.
Q: Is there enough ammonia in urine to create a dangerous reaction with bleach pooled in the bottom of a urinal?
So yes, very bad.
Ammonia is created from the break down of the Urea in urine.
In fact, it is this reason; (from the Wikipedia page on Urine);
“In pre-industrial times urine, being rich in ammonia, was used – in the form of lant – as a cleaning fluid. Urine was also used for whitening teeth in Ancient Rome.”
Just don’t tell your girlfriend that peeing in her mouth will whiten her teeth. 
I always felt like the bleach+ammonia got a bad rap. So you make a little chloramine, big whoop. It’s used as a disinfectant anyways (OK, I’m being a little flippant: I’m sure with enough of both products in a small enough space, it could be dangerous).
Mixing acid with bleach is much more dangerous, as you’ll liberate chlorine gas.
I don’t think so, no. Ammonia is extremely reactive stuff, and would cause you great pain in the member if present in your urine. What’s in urine is urea, and ammonia is produced by bacterial action on urea once it gets outside the body.
There’s the question of whether urea reacts with bleach, and the answer seems to be yes:
http://www.chemaxx.com/explosion16b.htm
But we already know bleach tends to produce a little Cl2 anyway as it decomposes, and Cl2 is very irritating to the eyes, so that’s what I’d guess you experienced. It probably just took a little while for enough of it to dissolve in your tears to start to irritate your mucosa, and the fact that this happened after you started peeing is pure coincidence.
I quite often leave some bleach in my toilet, and then pee in it. It does make it fizz a bit, and the chlorine smell in my bathroom (already there thanks to the bleach) does seem to increase a little, but not hugely, and not to the extent of causing any discomfort. I am pretty sure it hasn’t killed me yet.
Presumably there is quite a lot of other stuff in urine besides urea. There’s something that makes it yellow for a start. Are we sure it is the urea and not some other ingredient that is causing the slight release of chlorine?
But anyway, as buddy431 says, it is acid with bleach that is actually potentially dangerous. I think most actual accidents of this sort come from mixing bleach with bisulfate based toilet cleaners.
Since the bleach is a really good disinfectant, there would be very little bacteria in the water in the first place, so very little ammonia.
Can somebody run me through the basic chemistry again? IIRC, there are two things that can happen if you mix bleach and ammonia: it can give off a poisonous gas, or it can form a brown oily substance that floats on water and is an impact explosive. I thought the critical issue is whether the mix is equimolar or not. So what’s the straight dope? How does it go again?
That was a foolish thing to do. The very least you could have done was to flush before you used the toilet. You could have been asphyxiated!
People manage to die doing it - I think that’s probably why it’s generally viewed in a bit of a negative light.
So what? This isn’t a dichotomous situation where someone is pointing a gun at your head and telling you that you have to mix bleach with something - so what’s it gonna be? - ammonia or acid?
A few janitors die every year from mixing bleach and ammonia. It’s a real danger. Mangetout, don’t mix bleach with anything except water. When I was a factory janitor, we had to attend yearly haz-mat classes, and that’s what they told us.
Another thing you’re more likely to encounter in a rest room is hydrochloric acid-based toilet cleaning products. It’s a fierce thing, sorta the chainsaw of the janitor’s toolbox. It reacts with the lime from hard water and with the mineral deposit urine leaves, and it exudes an eye-and-nose-burning vapor cloud, especially if it is used on several toilets at once.
I can’t tell you if that vapor is poisonous, but I never wanted to hang around it. Your janitor should have flushed it away before she left.
I think that’s what I said.
Zombie alert:
I usually clean my toilets with bleach. This time I used about double the amount as normal, since I bought a new jug without realizing I still had a full jug at home.
So, I poured about a cup or two of bleach into both toilets, scrubbed and let it stand for an hour or so till I needed to pee.
About half way through having a nice long relaxing pee into one of the toilets I was overcome with fumes that caused my eyes and throat to start burning. This was about a half hour ago and I’m still experiencing an uncomfortable sensation in my nasal passages.
Just a public service message, I suppose. Beware.
My wife mixed bleach and ammonia when cleaning the bathroom one time and lost her breath, I had to call the paramedics. She started off coughing and passed out by the time she ht the living room. She did recover with some oxygen but they brought her to er for observation.
And that’s why you’re a zombie now!
Decades ago I worked at a full service car wash. We’d mix up ammonia and water in a bucket to make our own window cleaner. We’d then dip little spray bottles into the bucket for cleaning the interior windows of the cars.
We also had a big industrial washing machine for the white towels that we used. We’d use bleach to clean the towels. (I bet you can see where this is heading).
The bleach and ammonia bottles looked almost the same being plain white with similar labels including the skulls. They were even in the same storage room. All too often we’d get a newbie who would refill the window washing bucket with water and bleach instead of water and ammonia. Depending on how much of the original window cleaning fluid was still in the bucket, or worse, in your spray bottle, we’d get a lung-full or three of the dangerous combination. We had to evacuate the place more than one time.