We’ve all been taught that water freezes at 32 degrees Fahrenheit, 0 degrees Celsius, 273.15 Kelvin. Scientists have found liquid water as cold as -40 degrees F in clouds and even cooled water down to -42 degrees F in the lab.

Liquid nitrogen is much colder than dry ice—usually between -346°F and -320.44°F—which also makes it more dangerous to handle.

Dry ice can be a very serious hazard in a small space that isn’t well-ventilated. As dry ice melts, it turns into carbon dioxide gas. In a small space, this gas can build up. If enough carbon dioxide gas is present, a person can become unconscious, and in some cases, die.

Steve: Since the dry ice sank, that means it’s denser than liquid nitrogen is. So, to answer the question, “What happens when you mix dry ice and liquid nitrogen?” You get colder dry ice and less liquid nitrogen!

As dry ice melts, it undergoes sublimation (i.e., direct conversion from a solid into gaseous CO2, bypassing the liquid state). Improper ventilation during use, transport, or storage of dry ice can lead to inhalation of large concentrations of CO2 with subsequent harmful effects, including death (1,2).

Touching dry ice is a lot like touching something that is very hot, like a hot plate. The dry ice can freeze tissue in your mouth, esophagus, and stomach. However, the most significant risk is from sublimation of dry ice into gaseous carbon dioxide. Dry ice should never be consumed.

An 8 lb brick of dry ice, in a well-insulated container, should last about 12-24 hours. It will depend on how well insulated the container is, and how warm the outside temperature is. To be safe, buy it close to the time you want to use it.

To dispose of dry ice, place it in a well-ventilated area at room temperature; the remainder of the ice will sublimate away. Never dispose of dry ice in a trash can, chemical waste container or other garbage/waste can.

Make sure to follow all dry ice safe handling precautions. Fill a metal or plastic container half full of hot water and add a few pieces of dry ice every 5-10 minutes. As the water cools, you will need to add more hot water to maintain the fog effect.

Fun Things to Do with Dry Ice!

• Disappearing Ice. Place a regular ice cube and a cube of dry ice side by side on separate plates and watch to find that the dry ice will mysteriously disappear!
• Smokey Water.
• Smoke Bubbles.

To begin, it is very cold. The surface temperature of dry ice is a frosty 109.3 degrees below zero. If you were to touch it with your bare hands, it would cause nearly instant cell death, or frostbite. Always wear insulated gloves, or handle it with tongs, to avoid skin damage.

The affected area may sting, prickle, or burn, and have a deep cold feeling. This will progress into a tingling or a numbness. The skin may become red, white, or yellowish, but the skin will still be pliable and feel soft.

For severe cases, treatment must be sought within 24 hours. Treat a dry ice burn as you would treat frostbite or a burn from heat. A red area will heal quickly (a day or two).