The solid form of carbon dioxide is called dry ice. Dry ice is the perfect ingredient for fog, smoking volcanoes, and other spooky effects! However, you need to know how to transport, store, and use dry ice safely before you get it. Here are tips to help keep you safe.
How To Get and Transport Dry Ice
You can obtain dry ice from some grocery stores or gas companies. It's important to be prepared to transport dry ice before you purchase it. This will help it last longer and prevent accidents.
- Plan to get enough dry ice. It will sublimate at the rate of five to ten pounds each 24 hours (for pellets or chips), so if you won't be using the dry ice right away, plan for the loss of product. The rate of sublimation also depends on the exposed surface area. Dry ice pellets will convert to gas more quickly than a solid chunk of dry ice.
- Bring a cooler or a cardboard box. Your goal is to insulate the dry ice from warmer temperatures. It's also helpful to have a blanket or sleeping bag to wrap around the container to protect it from temperature changes.
- Usually dry ice is sold in paper bags. Set the paper bag inside the box or cooler. Close the lid to insulate the dry ice, but make sure it does not seal. This is important, because dry ice sublimates from its solid form into carbon dioxide vapor. The gas builds up pressure and could cause an explosion if it doesn't have a way to escape.
- As sublimation occurs, the level of carbon dioxide in the vehicle will rise. Make sure new air circulates into the vehicle to prevent carbon dioxide poisoning.
Storing Dry Ice
The best way to store dry ice is in a cooler. Again, make sure the cooler is not sealed. You can add insulation by double-bagging the dry ice in paper bags and wrapping the cooler in a blanket.
It's best to avoid putting dry ice in a refrigerator or freezer because the cold temperature can cause your thermostat to switch the appliance off, carbon dioxide levels could build up inside the compartment, and gas pressure could force open the door of the appliance.
Using Dry Ice Safely
The 2 rules here are (1) don't store dry ice in a sealed container and (2) avoid direct skin contact. Dry ice is extremely cold (-109.3°F or -78.5°C), so touching it can cause immediate frostbite.
- Use gloves or tongs to handle dry ice.
- Be aware cold carbon dioxide sinks, so risks from too much carbon dioxide are highest close to the ground or in any enclosed space. Make sure there is good air circulation.
- If you're using dry ice in drinks to produce fog, be careful you don't ingest the dry ice fragment. Ingesting dry ice is a medical emergency because of the tissue damage from frost bite and the pressure buildup from the release of gas. Dry ice sinks in a glass or bowl, so the risk of ingestion normally is very low. However, do not allow intoxicated people to drink dry ice cocktails or work with dry ice.
How To Treat a Dry Ice Burn
Treat a dry ice burn the same way as you would treat frostbite or a burn from heat. A red area will heal quickly (day or two). You can apply burn ointment and a bandage, but only if the area needs to be covered (e.g., open blisters). In cases of severe frostbite, seek medical attention (this is extremely uncommon).
More Dry Ice Safety Tips
- Never leave children or pets unattended around dry ice.
- Be aware of symptoms of carbon dioxide poisoning and make sure there is good air circulation where dry ice is used and stored. Ordinarily, slightly elevated levels of carbon dioxide don't pose a significant health risk. The levels of carbon dioxide are most likely to become too high near the ground.
- If you're using dry ice to chill food, you'll get the best results if you put the dry ice on top of the food. This is because cold sinks.
- Avoid setting dry ice directly onto counter tops or placing it in empty glass containers. The temperature shock could crack the material.
- Some airlines will allow you to carry dry ice, but not more than 2 kilograms. Expect the dry ice to sublimate at a slightly faster rate than usual because cabin pressure may be lower than normal pressure. Pack the dry ice with crumpled paper or a blanket to reduce loss.