Dry ice, the solid form of carbon dioxide (CO2), has an extremely low temperature of approximately -109.3°F (-78.5°C). Its low temperature makes it an effective cooling agent, but direct contact can cause severe injuries. These are cryogenic burns, similar to frostbite, caused by rapid tissue freezing. Understanding these injuries, their prevention, and proper response is important for safe handling.
The Nature of Dry Ice Injury
Dry ice causes injury by rapidly drawing heat away from skin and underlying tissues. When skin comes into direct contact with dry ice, the water within skin cells freezes almost instantly, forming ice crystals. These crystals can physically damage the cell membranes, leading to cellular destruction. The sensation is often described as a burning feeling because the cellular damage, though different from heat, triggers a similar pain response.
The body’s response to this extreme cold also involves the constriction of blood vessels in the affected area. This vasoconstriction reduces blood flow, further limiting oxygen and warmth to the tissue, which compounds the damage. Symptoms, similar to frostbite, include intense pain, numbness, tingling, and changes in skin appearance. The skin may initially appear red, then become pale, white, or even waxy. Blisters can form, and in severe cases, affected tissue may become hard or discolored, indicating deeper, long-lasting damage.
Essential Safety Precautions
Personal protective equipment (PPE) is important when handling dry ice to prevent direct skin contact. Insulated gloves, such as leather or specialized cryogenic gloves, are necessary, as thin gloves like nitrile do not offer sufficient protection. Eye protection, such as safety goggles or a face shield, is also advised, especially when small particles might splinter. Even brief contact with bare skin can result in frostbite or cold burns.
Proper ventilation is another important safety measure due to the sublimation of dry ice. Dry ice converts directly from a solid into carbon dioxide gas, which is heavier than air and can accumulate in enclosed spaces. This accumulation can displace oxygen, potentially leading to symptoms like dizziness, shortness of breath, or even asphyxiation. Therefore, dry ice should only be used or stored in well-ventilated areas.
Never use airtight containers, as pressure buildup from sublimating gas can cause them to rupture or explode. Insulated, breathable containers like Styrofoam coolers are suitable for storage. Dry ice should also be kept out of reach of children and pets.
Responding to Dry Ice Exposure
In the event of dry ice exposure, it is important to act promptly. First, carefully remove any clothing or jewelry from the affected area, unless frozen to the skin. If clothing is frozen, gently pour cold water over it until it detaches. Then, slowly warm the injured area by soaking it in lukewarm water, ideally around 104°F (40°C), for about 20 minutes. This rewarming process can be repeated after a 20-minute break if numbness or tingling persists.
Avoid rubbing the affected area, as this can cause further tissue damage. Direct heat sources, such as heating pads or radiators, should not be used for rewarming, and blisters, if present, should not be broken. Seek professional medical attention for any significant dry ice exposure, particularly if the skin shows persistent discoloration, numbness, or blistering. These may indicate deeper tissue injury requiring specialized treatment. Medical professionals can assess the extent of the injury and provide appropriate care to prevent complications.