Dry ice, the solid form of carbon dioxide, is a substance with an extremely low temperature, typically around -109.3°F (-78.5°C). While it serves many purposes, including specialized cooling and creating fog effects, it is generally not recommended to store dry ice in a standard home freezer. This article explains the reasons and provides safe alternatives for handling and storing dry ice.
Why Not Store Dry Ice in a Freezer
Dry ice does not melt into a liquid; instead, it undergoes a process called sublimation, transforming directly from a solid into a gas. A standard freezer, even at its coldest setting, is not cold enough to prevent this sublimation entirely. This continuous conversion from solid to gas poses several risks within the enclosed environment of a freezer.
Sublimation releases significant amounts of carbon dioxide gas. One pound of dry ice can produce approximately 250 liters of gaseous carbon dioxide. In a sealed or poorly ventilated space like a freezer, this gas can build up, displacing the oxygen present. Carbon dioxide is heavier than air, meaning it can accumulate in lower areas, creating a suffocation hazard if the freezer is opened in an unventilated room.
The extreme cold of dry ice can also negatively impact a freezer’s functionality and components. This intense cold can cause the freezer’s thermostat to malfunction, potentially leading the unit to shut down or overwork as it attempts to regulate the temperature. Additionally, prolonged exposure to such low temperatures can damage plastic shelves or interior parts, and can freeze nearby food items too severely.
Safe Handling and Storage Alternatives
Due to the hazards of freezer storage, dry ice requires specific handling and storage methods. It is crucial to store dry ice in a well-ventilated area, such as outdoors or in a garage with an open door, to allow the sublimating carbon dioxide gas to disperse safely. Never store dry ice in a sealed room or vehicle, as the gas can accumulate and displace oxygen.
For temporary storage, an insulated cooler, such as a Styrofoam or hard-sided cooler, is suitable. However, the cooler’s lid must not be airtight; pressure from the continuous release of carbon dioxide gas can cause the container to rupture or explode. When handling dry ice, always wear heavy, insulated gloves and eye protection to prevent frostbite and protect against accidental contact with the extremely cold substance.
Safe Disposal of Dry Ice
Proper disposal of dry ice prevents accidents. The safest method for disposing of any leftover dry ice is to allow it to sublimate completely into the air. Place the dry ice in a well-ventilated outdoor area, away from children and pets, where the carbon dioxide gas can dissipate harmlessly.
Never seal dry ice in airtight containers or plastic bags during disposal, as pressure from the sublimating gas can cause explosion. Furthermore, never dispose of dry ice by placing it down a drain, toilet, or sink. The extreme cold can cause pipes to freeze and crack, leading to significant plumbing damage.