If you’re planning on going a long hiking or outdoors trip, then you’re probably thinking about how you’re going to be keeping your food from perishing. This is where dry ice comes in. How long does dry ice last? What’s the best way to make it last longer? These are all important things that we’ll be going over so you can better prepare for your trip. Without further ado, let’s gets started!
What is Dry Ice Anyway?
Dry ice is just frozen carbon dioxide. It’s surface temperature is -109.3 degrees Fahrenheit and -78.5 degrees Celsius.
Dry ice also turns directly into a gas when it breaks down, rather than becoming a liquid like other elements.
It has over 2 times the cooling energy per pound and even 3 times the cooling energy per volume than typical ice made from water.
What is Dry Ice Used for?
Because of it’s extremely cold temperature, dry ice is best used for keeping things frozen and freezing things. It is commonly used to keep items frozen for longer amounts of time than ice would, which is extremely useful for camping and hiking trips.
Believe it or not, you shouldn’t store dry ice in the freezer, since it will actually shut it off due to it’s extreme cold temperatures.
How Long Does Dry Ice Last?
The amount of time dry ice lasts completely relies on the method of storage is being used. Considering that dry ice is typically available in 5 pound bricks, this is what the following time measurements apply to. Dry ice lasts for the following amounts of time:
- When placed in a cooler, dry ice can last from 18 to 24 hours.
- Dry ice lasts anywhere from 3 to 5 hours when left outside.
- Placed in liquid, dry ice will last from 15 to 45 minutes.
How to Store Dry Ice to Extend Shelf Life?
Keep in mind, dry ice should never be touched or handled with the skin since it will cause severe burns. This is also true for tasting as well. You should only handle dry ice with protective cloth or leather gloves (you can use a towel or oven mitt as well).
Like mentioned earlier, dry ice should never be stored in your freezer. Likewise, it is never safe to store dry ice in an airtight container. Why? This is because as dry ice turns into gas, pressure can build up inside and cause the container to burst.
The best way to store dry ice in an insulated cooler with a loosely closed lid. The cooler should also be placed in a well ventilated area, or if outside, a shady spot.
Packing Dry Ice When Traveling and Camping
If you are planning to use dry ice to keep food cold when traveling or camping, this part is definitely your must-read guideline.
It’s important that when using dry ice, it should be only for frozen goods. Anything that you want to keep cool, but not frozen, should be stored in a separate cooler with regular ice. Plan on using 10 to 20 pounds of dry ice per 24 hour time frame. This does depend on the size of the ice cooler you are using, so take that into consideration.
A general guideline on how much ice you’ll need is to use 10 pounds of dry ice per 15 inches length of your ice cooler. This will either be 2 x 5 pound dry ice blocks or 1 x 10 pound dry ice block. For a 40 quart cooler, 20 pounds of dry ice should be used. Larger ice coolers should also follow the general guideline mentioned earlier.
Because of the way cold sinks, the best way to pack dry ice is on top of the food. Because this is less convenient, it is alright to place the dry ice underneath instead. Any empty space in the container should be filled in with either crumpled newspaper, or any other kind of filler. This is because additional space is going to cause the dry ice to sublimate quicker.
A trick you can use to help dry ice last longer is by lining the inside of your ice cooler with Styrofoam. The more dry ice that is placed in the cooler, the longer it will last as well. Doing things like surrounding your ice cooler with insulating items (sleeping bags) or placing it in the ground will elongate the life of the dry ice. It’s always best to purchase dry ice as needed since it’s shelf-life isn’t too long.
Additional Dry Ice Precautions
Now that you know a lot about dry ice, it’s important to elaborate and go over some important safety precautions to take when dealing with dry ice.
- Dry ice should never be stored in the freezer! This will shut off the freezer due to extreme temperatures.
- Never store dry ice in an airtight container. Doing so will cause the container to burst, potentially causing harm with the debris and explosion.
- Don’t use dry ice for goods you don’t want to keep frozen, this will freeze it. These items should be stored separately in a cooler with regular ice.
- Thawing times for goods kept frozen with dry ice will be longer due to the extreme temperatures.
- When transporting dry ice in a vehicle, keep the windows down. Failing to do so will cause difficulty breathing and can be dangerous.
- It is important to never sleep in the same room the dry ice is being stored in.
- Dry ice should NEVER come into contact with your skin or mouth since this will cause serious burns and injury. Always handle dry ice while wearing gloves or with a towel , or even with tongs.
- Whatever room the dry ice is stored in should be well ventilated.
- Disposal of dry ice should be done by leaving it outside, or by placing it in a bucket of water in a ventilated area.
Dry ice is extremely useful and efficient at keeping frozen food…well, frozen! Especially if you are on a long trip outdoors, dry ice will keep your camping food lasting longer. Make sure to follow the guidelines and safety precautions to avoid any problems.