Dry ice is simply frozen carbon dioxide (CO2). That means that it is extremely cold. When you bring it to the room temperature, it swiftly sublimes; changes from solid to gas as its molecules escape. And when you drop dry ice in pool, it bubbles rapidly as the CO2 sublimes.
How Carbon Dioxide Freezes
Molecules in solids and liquids are held together by ionic/intermolecular interactions/connections – attractions between negative and positive ions. The connections between molecules in CO2 are slightly weak, so they need to be cooled to a very low temperature before they form ice.
That is because the temperature is the measure of the average energy in motion. Therefore, cooler temperatures mean that the average molecule in CO2 is moving really slowly. When the temperature reaches below the CO2 freezing point, its molecules move slowly enough to allow the weak interactions forces to hold them together and form a cub or solid.
Dry Ice in Pool
Water molecules in your swimming pool are at a higher temperature than the frozen CO2, so collisions transmit energy to the dry ice from the water molecules, cooling down your pool’s water while warming up the dry ice.
When the molecules on the surface of the frozen CO2 move more quickly, they gain sufficient energy to break free of the ice and transform into a gas. The huge excess of dry ice produced forms a vast amount of bubbles; that’s why frozen CO2 is quite popular in classroom demonstrations.
Safety with Carbon Dioxide
So, can you put dry ice in a pool? Of course, you can, but you shouldn’t put frozen CO2 in your pool.
Your body requires oxygen. As it transforms to gas, the frozen CO2 displaces a lot of oxygen, temporarily forming an area of high carbon dioxide concentration. Consequently, it acts like an Asphyxiant – a chemical that removes oxygen and can be hazardous.
- You shouldn’t put dry ice in your indoor pool.
- Depending on the amount of dry ice you have added to your pool (indoor or outdoor), the air immediately above your pool will instantly have a higher concentration of carbon dioxide than the surrounding areas, at least until the high levels disappear.
- You shouldn’t add a huge amount of frozen CO2 in your swimming pool and then dive in.
- You shouldn’t leave a huge amount of dry ice in a closed space.
3 Dangers of Adding Dry Ice in Your Pool
By now you know that the dangers associated with frozen CO2 are because of sublimation into gas and extremely cold temperature.
Dry Ice Frostbite – Frozen CO2 is pretty cold. Slight skin contact can kill your cells, resulting to a dry ice burn. The worse part, it only takes a few seconds to get burned, so it is best to avoid adding dry ice in your swimming pool.
Also, imagine if you accidentally swallowed this ice when swimming. So, you should be careful if you intend to add dry ice to your pool.
Asphyxiation – Frozen CO2 forms CO2 gas. Although the gas isn’t toxic, it interferes with the composition of the air so that there is a limited supply of oxygen. This might not be a problem in an outdoor swimming pool but will cause problems in an indoor pool.
Additionally, the cool CO2 gas sinks to the surface of the room. This means that the increased concentration of CO2 will highly likely affect your children and pets than for grown up. That’s because they have a heightened metabolism and are near the surface where the gas is in high concentration.
Explosion Hazard – Frozen CO2 is not explosive or flammable, but it exerts lots of pressure as it changes to a gas. If you place dry ice in a sealed container near your swimming pool, there is a chance of the container exploding.
A frozen CO2 bomb produces a loud noise and dispatches parts of the dry ice and container. You can easily harm your ears and even become injured by the dispatched parts.
To avoid this, don’t seal dry ice in a jar or bottle. All even better, don’t try to add dry ice in your pool.
It is quite risky to add dry ice in pool. Therefore, do not try to add this product to your swimming pool for any reason.