Dry Ice is the solid-state of Carbon Dioxide that is colorless, non-flammable, with a sour zesty odor, and can lower the pH of a solution when dissolved in water. Dry ice sublimates, transforms from its solid state to gaseous carbon dioxide without becoming a liquid, at -78.5°C. This extreme temperature makes handling dry Ice without the proper protection or knowledge dangerous, as it can cause frostbite or in confined spaces hypercapnia. Dry Ice is mainly used as a coolant due to its low temperature, especially when compared to Ice made from water. And it is also valued for the lack of residue it leaves behind.
Carbon Dioxide gas is pressurized and refrigerated until it liquefies. The pressure of the Liquid Carbon Dioxide is then quickly reduced, and the liquid carbon dioxide vaporizes, causing a rapid lowering of the temperature of the remaining liquid. As a result, the extreme cold causes the liquid to solidify into a snow-like consistency. And Finally, the snow-like solid carbon dioxide is compressed into small pellets or larger blocks of dry Ice.