Dry ice is the solid form of carbon dioxide (CO2). The simple answer to whether you can put it in your mouth is an emphatic no. This substance is an extreme cryogenic agent, and direct contact with the sensitive tissues of the mouth, throat, or digestive tract is profoundly dangerous. The risks are severe, ranging from immediate, deep-tissue injuries to life-threatening internal pressure and respiratory distress.
The Extreme Nature of Dry Ice
The primary danger of dry ice stems from its exceptionally low temperature, approximately \(-109.3^\circ\text{F}\) (\(-78.5^\circ\text{C}\)). This temperature is far colder than conventional water ice, creating a powerful thermal gradient upon contact with human tissue. Due to this intense cold, dry ice is classified as a cryogen.
Dry ice also exhibits sublimation, converting directly into carbon dioxide gas without passing through a liquid phase. This process happens rapidly when dry ice is exposed to the warmer environment of the human body, absorbing significant heat from surrounding tissues. This quick phase change drives both the cryogenic injury and the internal pressure risk. Even a brief touch can cause a freeze burn by freezing moisture and tissue on contact.
Immediate Physical Injuries and Health Risks
Placing dry ice in the mouth or swallowing it causes two severe categories of injury: cryogenic burns and internal barotrauma. The extreme cold instantly freezes the water within cells, causing damage akin to severe frostbite. This cryogenic burn can affect the lips, tongue, oral mucosa, pharynx, and esophagus, leading to tissue necrosis and permanent loss of function.
The rapid freezing can cause tissue to become brittle. If dry ice adheres to the tongue or lips, attempting to remove it can cause severe damage. Internal injuries are concerning because the damage is not immediately visible. Severe frostbite to the soft tissues of the throat can cause significant edema, or swelling, which may obstruct the upper airway, potentially requiring emergency medical procedures like intubation or tracheostomy.
The second major danger is the rapid expansion of carbon dioxide gas during sublimation if the dry ice is swallowed. As the solid converts into gas inside the confined space of the stomach or gastrointestinal tract, it dramatically increases in volume. This rapid increase in internal pressure can lead to severe abdominal pain, bloating, and vomiting. Pressure buildup may cause a gastric perforation or rupture of the stomach lining, which is a life-threatening medical emergency.
Safe Handling and Emergency Response
Dry ice must always be handled with specific safety precautions to prevent accidental contact. Use insulated gloves or tongs when moving dry ice to protect bare skin from the cryogenic burn risk. Furthermore, because the solid sublimates into a large volume of CO2 gas, dry ice should only be stored and used in well-ventilated areas. CO2 gas is heavier than air and can accumulate in low or enclosed spaces, potentially displacing oxygen and creating an asphyxiation hazard.
If accidental contact occurs, such as a localized burn on the skin, the area should be treated similarly to frostbite. The affected area should be warmed gently with lukewarm water, ideally around \(104^\circ\text{F}\) (\(40^\circ\text{C}\)), for up to 20 minutes. Do not use hot water or rub the frozen tissue, as this can cause further damage. If the skin remains numb, stiff, or cold after warming, or if blistering occurs, immediate medical attention is necessary, indicating a severe tissue injury.