APART from the obvious there’s a more serious reason why you shouldn’t pee in the swimming pool — it could be deadly.

It’ll make you shudder, but the hard reality is most people have used a swimming pool as a toilet. The promise that chlorine kills any germs and covers their sins is the main reasoning behind the act. Even Olympic swimmers have admitted to doing it.

But new research by the China Agricultural University and Purdue University has found this mixture of uric acid (found in urine) and chlorine can produce a substance harmful enough to be used as a weapon.

Within an hour of mixing urine and chlorine the researchers found it created trichloramine and cyanogen chloride — both chemicals are associated with lung problems but cyanogen chloride can affect the nervous system and is classified as a controlled substance in chemical warfare under the U.S. Chemical Weapons Convention due to its toxicity and ability to penetrate gas masks.

The guilty of you out there will be asking why you’re okay after doing it for years. The fact is, in order to create an amount of cyanogen chloride to be considered deadly it would take A LOT of leaky swimmers in one chlorinated pool. More swimmers than any pool could contain.

While this may come as some relief, the authors of the research imply how hygiene conditions can be improved if people are willing to use the bathroom instead of the deep end.

“Given that uric acid introduction to pools is attributable to urination, a voluntary action for most swimmers, these findings indicate important benefits to pool water and air chemistry that could result from improved hygiene habits on the part of swimmers.”