What's Inside an Ice Pack?
The Bottom Line
Ice packs are common household items; some are intended for single-use only, while others are intended to be reused many times. Typically, unintentionally swallowing some of their liquid contents usually causes minor effects such as mouth irritation. However, depending on the ingredients and the amount swallowed, ice packs do have the potential to cause toxicity.
What’s inside an ice pack?
Ice packs are found in millions of homes, as they are used for a wide variety of purposes, such as icing an injury and keeping food cold. They come in many forms and contain different ingredients depending on the type of ice pack.
Reusable ice packs typically contain water, something to lower the freezing temperature, a thickening agent, silica gel, and non-toxic blue coloring. These ice packs turn into solids when frozen but are soft and squishy when thawed. Other kinds of reusable ice products come in different forms, like reusable ice cubes with liquid (usually distilled water) in them and ice packs filled with small gel beads.
There are also one-time-use "instant" ice packs, which can be found in many first-aid kits. These are stored at room temperature and only turn cold when squeezed. Depending on the type of ice pack, results of exposure can range from nontoxic to serious.
What happens if you ingest chemicals from an instant ice pack?
The most concerning type of ice pack is the instant ice pack. These are filled with water and a chemical reactor. When the bag is squeezed, the chemical reactor is released and it interacts with the water to start a reaction that lowers the temperature of the water to almost freezing. The chemical reactors in these ice packs are typically ammonium nitrate, calcium ammonium nitrate, or urea. Of these, the most toxic ingredient if swallowed is ammonium nitrate.
If ingested, ammonium nitrate can cause dilation of blood vessels. This can lower blood pressure and reduce the amount of blood flowing to body organs. It might also cause conditions called methemoglobinemia (impairment of the oxygen-carrying ability of red blood cells) and hemolysis (destruction of red blood cells). Symptoms of methemoglobinemia and hemolysis include bluish coloring, especially of lips or nail beds, shortness of breath, dizziness, fatigue, and headache.
Calcium ammonium nitrate is a mixture of calcium carbonate and ammonium nitrate. Since calcium carbonate is nontoxic, calcium ammonium nitrate is less toxic than a comparable amount of ammonium nitrate. Calcium ammonium nitrate still has the same toxic properties as ammonium nitrate, but it requires a larger swallowed amount to have the same effect. Urea is the least concerning reactor in instant ice packs, but it can cause nausea, vomiting, dizziness, drowsiness, and confusion if enough is swallowed.
What happens if you ingest chemicals from a reusable ice pack?
The concerning component in reusable ice packs is the ingredient used to lower the temperature, which is usually propylene glycol. A small taste of reusable ice pack liquid typically only results in mild irritation. With large ingestions, it is possible to develop symptoms similar to alcohol intoxication, such as severe drowsiness, unresponsiveness, and slowed breathing. Some early reusable ice packs contained very toxic substances, such as diethylene glycol or ethylene glycol (antifreeze). These types of ice packs have been recalled and should no longer be available.
The gel beads in some ice packs are usually made of sodium polyacrylate, which can be irritating if swallowed.
Can chemicals in ice packs harm the eyes or skin?
The chemicals in ice packs can be irritating to the eyes and skin. The degree of irritation will vary with the chemical involved and the duration of exposure. Eye exposures should be treated with immediate irrigation of the eyes with room temperature water for 15 minutes. Persistent eye pain or other symptoms might need medical examination and treatment. Skin exposures should be immediately washed with soap and water. Most often, symptoms cause by skin and eye exposures will improve quickly with irrigation of the affected area.
An additional danger of ice packs is the possibility of skin damage, including frostbite, that can occur with prolonged contact. People who use ice packs too often can develop a type of tissue damage called ice-pack dermatosis. When this happens, the skin may appear red and inflamed with purplish patches. Sometimes the skin can look marbled and develop ulcers. Always read the instructions on an ice-pack product before applying it to the skin.
Treatment for ingestions
Treatment for the ingestion of modern ice pack contents is rinsing out the mouth and drinking a few sips of water to clear the mouth and throat. Mild irritation and upset stomach can be managed at home with small sips of water.
If you think someone might be having adverse effects from a reusable ice product, immediately call Poison Control at 1-800-222-1222 or check the webPOISONCONTROL online tool for help. Whether you call or log on, expert assistance is available 24 hours a day.
Diana N. Pei, PharmD
Certified Specialist in Poison Information
Revised William G. Troutman, PharmD
Professor of Pharmacy Emeritus
Poisoned?
Call 1-800-222-1222 or
Prevention Tips
- Use ice packs according to the instructions. Generally, ice pack use should be limited to 20 minutes or less per session.
- Avoid applying ice packs directly to skin. Place a towel or cloth between the ice pack and the skin in order to avoid cold-induced injury.
- Discard any broken or leaking ice packs.
- Closely supervise children using instant ice packs.
This Really Happened
Case 1. Poison Control was contacted by a school nurse after an 8-year-old boy's reusable ice pack broke in his lunchbox. He licked some of the gel, thinking it was yogurt. He had no symptoms at the time of the call other than being anxious. Poison Control instructed the nurse to give the boy a drink of his choice to help dilute what he had swallowed. Poison Control called the school nurse 1½ hours later and learned that the boy remained asymptomatic and had returned to class.
Case 2. Poison Control was called by a father of a 2-year-old girl who was found sucking on an instant ice pack that had a pinhole in it. When the father squeezed the ice pack, some liquid came out, but the girl denied eating any. The ingredients listed were calcium ammonium nitrate and water. Poison Control confirmed with the father that the girl had no medical conditions that would increase her risk for methemoglobinemia. Poison Control followed up with the father 2 hours later, and the girl remained asymptomatic.
For More Information
What's the difference between instant cold packs, gel packs, and clay packs? Icewraps. December 25, 2019. Accessed May 2, 2025.References
Challoner KR, McCarron MM. Ammonium nitrate cold pack ingestion. J Emerg Med. 1988;6(4):289-293.
Lecklitner I. What's in this? Cooler ice packs. MEL Magazine. Accessed May 2, 2025.
Smyth D. How do instant ice packs work? eHow. Updated October 18, 2021. Accessed May 2, 2025.
What are the ingredients in gel ice packs? Reference. Updated August 4, 2015. Accessed May 2, 2025.
Poisoned?
Call 1-800-222-1222 or
Prevention Tips
- Use ice packs according to the instructions. Generally, ice pack use should be limited to 20 minutes or less per session.
- Avoid applying ice packs directly to skin. Place a towel or cloth between the ice pack and the skin in order to avoid cold-induced injury.
- Discard any broken or leaking ice packs.
- Closely supervise children using instant ice packs.
This Really Happened
Case 1. Poison Control was contacted by a school nurse after an 8-year-old boy's reusable ice pack broke in his lunchbox. He licked some of the gel, thinking it was yogurt. He had no symptoms at the time of the call other than being anxious. Poison Control instructed the nurse to give the boy a drink of his choice to help dilute what he had swallowed. Poison Control called the school nurse 1½ hours later and learned that the boy remained asymptomatic and had returned to class.
Case 2. Poison Control was called by a father of a 2-year-old girl who was found sucking on an instant ice pack that had a pinhole in it. When the father squeezed the ice pack, some liquid came out, but the girl denied eating any. The ingredients listed were calcium ammonium nitrate and water. Poison Control confirmed with the father that the girl had no medical conditions that would increase her risk for methemoglobinemia. Poison Control followed up with the father 2 hours later, and the girl remained asymptomatic.