Let’s face it: peeing in the pool is more common than most people admit. But aside from the obvious “ick” factor, what actually happens when urine mixes with chlorinated water?
First, the basics: chlorine is added to pool water to kill bacteria and keep swimmers safe. But chlorine doesn’t just float around doing nothing — it reacts with anything organic, including sweat, dirt, and yes… pee.
When urine (which contains compounds like urea, ammonia, and creatinine) hits chlorinated water, a chemical reaction occurs. This reaction creates chloramines, particularly trichloramine, which is responsible for that strong “pool smell” people often mistake for chlorine. In reality, a well-maintained pool shouldn’t smell much at all.
And it gets worse — chloramines don’t just smell bad; they also irritate your eyes, lungs, and skin. According to the CDC, breathing in chloramine-laced air (especially in indoor pools) can aggravate asthma and cause coughing or wheezing. High levels of chloramines can even lead to respiratory problems in swimmers and lifeguards.
In 2014, researchers from Purdue University discovered that when chlorine interacts with uric acid from urine, it can also produce cyanogen chloride, a compound classified as a potential chemical warfare agent in high concentrations. Don’t panic — pool levels are nowhere near dangerous — but it’s a pretty good reason to think twice before letting it flow.
Remember: Urine isn’t sterile in a pool. It creates chemical byproducts that are unpleasant at best and irritating at worst. So next time you’re tempted to skip the bathroom break, just remember — you’re not just peeing in water… you’re peeing into a chemical reaction that affects everyone around you. Use the restroom. The pool — and your fellow swimmers — will thank you.
