Dry ice is the trademark name for frozen carbon dioxide or CO². In use for decades, dry ice has become increasingly popular in the past 30 years.

The most common use for dry ice has to do with the food industry, where it's used to preserve perishable items and to carbonate liquids. Adding dry ice to any fruit juices or water will result in a sparkling drink. For example, it's possible to prepare homemade root beer by adding dry ice to root beer extract mixed with water. Dry ice also prevents the growth of bacteria, so it can be used to preserve dry seeds, grains, and flour and to retard baking yeast growth.

A sample use for dry ice is to freeze fruits. Fruits frozen with dry ice will thaw firm, not soggy. Pop Rocks, a carbonated candy that "explodes" when put in the mouth, is made with pressurized dry ice. Campers have another use for dry ice: they can keep food fresh for a longer period of time without having to worry about sogginess.

Another use for dry ice has to do with medicine, where it's commonly used to preserve and ship biological samples. Cosmetic surgeons use dry ice to freeze warts for easy removal.

The entertainment industry also has a popular use for dry ice. The "fog" used in special effects is made with dry ice. When dry ice comes in contact with water, it condenses and forms a thick white fog. This can be effected with a fog machine or a simple deep metal plate. Because dry ice can shrink metal, a common use of dry ice is to pop out small dents and to shrink machine parts before assembly.

A lesser known use for dry ice has to do with keeping mosquitoes and wood beetles away. Mosquitoes are attracted to CO² and naturally flow towards dry ice. Place some pieces of dry ice around a mosquito trap to keep mosquitoes away. Wood beetles can be eliminated from furniture by placing the piece inside a sealed freezer with several pounds of dry ice. The insects and eggs will suffocate within 24 hours.

Dry ice can be dangerous if not handled properly. With a temperature of -109.3°F (-78.5°C), dry ice can severely burn the skin and cause suffocation if inhaled. The use of special gloves is highly recommended when handling dry ice. If working with dry ice indoors, make sure the space is well ventilated.