Dry ice is carbon dioxide (\(\text{CO}_2\)) in its solid form, primarily used as a chilling agent or for creating dramatic fog effects. It is extremely dangerous to ingest solid dry ice under any circumstances. Direct consumption causes immediate, severe internal injuries, requiring emergency medical attention.
The Physics of Dry Ice and Sublimation
Dry ice maintains an extremely cold temperature of approximately \(-109.3^\circ\text{F}\) (or \(-78.5^\circ\text{C}\)) at standard atmospheric pressure. This frigid temperature is the source of its cooling power and its danger.
The physical process defining dry ice is sublimation, the transition directly from a solid state to a gas state without becoming a liquid. When dry ice absorbs heat, it converts into carbon dioxide gas, leaving no liquid residue.
This rapid phase change creates the famous “smoke” effect when dry ice is dropped into water, causing water vapor to condense. The sublimation process is also the source of severe internal danger upon ingestion, as the solid rapidly converts into a large volume of gas inside the body.
Immediate Health Risks of Ingestion
Ingesting solid dry ice presents two distinct, life-threatening hazards: cryogenic burns and massive internal pressure buildup. Both mechanisms cause severe damage to the delicate tissues of the digestive tract.
The extreme cold of the solid \(\text{CO}_2\) causes immediate, severe tissue damage, similar to frostbite, known as a cryogenic burn. This can affect the mouth, throat, esophagus, and stomach lining instantaneously upon contact.
Tissue freezes rapidly, leading to necrosis (tissue death). The extent of the damage depends on the size of the piece and the duration of contact.
A second, equally serious danger arises from the sublimation of the dry ice within the body, typically in the stomach. As the solid turns into gas, it rapidly and dramatically increases in volume. This immense volume increase creates severe pressure inside the stomach and intestines.
This internal pressure can cause intense abdominal pain, bloating, and, in severe cases, rupture or perforation of the stomach or intestinal wall. Perforation requires immediate surgical intervention to prevent widespread infection.
Safe Use of Dry Ice in Food and Drinks
Despite the severe hazards of ingestion, dry ice is commonly used safely in the food and beverage industry to create chilling and fog effects. The guiding principle for safe use is ensuring that the solid \(\text{CO}_2\) never comes into contact with the consumer.
For punch bowls or large containers, the dry ice should be placed in the liquid and allowed to sublimate completely before any portion is served. The dense fog it creates will hover low over the liquid, providing the desired visual effect.
When used in individual cocktails, the pieces of dry ice should be large enough that they cannot be accidentally swallowed and must be removed with tongs before consumption. Some specialized bars use sealed infusers or stir sticks designed to hold the dry ice, separating the solid from the beverage.
The drink is safe to consume once the bubbling and fog effect has stopped, indicating the dry ice has fully sublimated into gas. Only “food-grade” dry ice should be used near consumables.
What To Do In Case of Accidental Ingestion
Accidental ingestion of solid dry ice is a medical emergency demanding immediate action. The first step is to call emergency services or poison control.
Do not attempt to induce vomiting in the affected person. Vomiting can increase the risk of gas expansion and potential rupture inside the body.
While waiting for medical professionals, keep the person calm and monitor their breathing. Do not give the person anything to eat or drink unless advised by emergency medical personnel. The primary focus must be on transporting the individual to a hospital immediately for assessment of internal damage.