My apartment complex pool was closed today due to a resident dumping a large quantity of dry ice into the pool. In the notification from my landlord, they stated:
Dry ice is frozen carbon dioxide and not only imbalances the pool, but can cause burns due to the below freezing temperatures.
My understanding of dry ice being added to water is that it would sublimate and carbonate the water, causing a minor temperature decrease, and creating a low-hanging cloud of carbon dioxide gas on top of the surface (since it's heavier than air).
However, it would seem that if the dry ice indeed does cause "below freezing temperatures", that would just freeze the water; so, unless you already in the water, you shouldn't get a freeze-burn.
I've done a bit of searching, but most material talks about burns from solid dry ice, not from adding it to water.
- One thread on Reddit suggests that freeze-burns are more possible from dry ice gas if the skin is wet, but there are no citations.
Direct contact with the liquefied [carbon dioxide] gas can chill or freeze the skin (frostbite).
... but refers to liquefied gas, not gas in the gaseous state.
- Wikipedia doesn't list any particular safety concerns aside from handling of liquid or solid carbon dioxide.
So, here's what I'm wondering: How does dry ice affect the pool's pH, and to what extent? How does it affect the temperature, and to what extent? And what other side effects (mostly harmful ones) would arise from the addition of dry ice to a swimming pool?