If you’re embarking on some cool culinary adventure, but you’ve found yourself stuck and wondering how long dry ice lasts, I’ve got the details you’re looking for.
Dry ice, known in science class as solid carbon dioxide, is used across industries to transport multiple items that require a cold chain in the food and medical industry. No matter what you are planning to do with it, understanding its shelf-life is pretty important.
How long does dry ice last?
There are a number of factors that will contribute to how long your piece of dry ice will last, mostly the temperature of your storage container and the volume of dry ice you have.
Generally speaking, a piece of dry ice will change from a solid to a gas (nope, not into water – remember it’s solid CO2 and not H2O) at a rate of about 5-10% per day, depending on how you’ve stored it.
The smaller the surface of dry ice exposed to the air, the longer the piece will last. The USDA indicated that dry ice could be used for transporting food for up to 2 days, so long as it doesn’t touch the food directly and the food is stored at -10°F or below.
It’s really important to take care when handling dry ice as you can actually burn your skin, and it can be dangerous if consumed. Dry ice can also cause eye irritation. It’s a great idea to wear a sturdy pair of gloves when working with dry ice and to make sure that the room you work in has plenty of fresh air.
If you are just keeping your dry ice out in the open air, the piece will sublimate a lot quicker than if it’s in a cooled storage facility. Humidity, heat, and wind will all speed up the process of it turning back into a gas. In the open air, your piece is likely to only last a few hours to a day, depending on the climate around it.
How long can I keep 1 lb of dry ice?
As previously explained, the time a piece of dry ice will last depends on a couple of factors, such as the temperature of the storage conditions and how that area is being used.
If you have a 1 lb piece of dry ice that is changing from a solid to a gas at a rate of 5-10% per day, you can expect it to last you between 10-20 days in a freezer.
Planning to use it within 10 days will be safest. Even with a small piece of dry ice, remember to handle it with care.
The shelf-life will depend on how well-insulated the storage facility is. If the door is peeping open even a little, the dry ice will start to sublimate (turn back to gas) quicker.
If you’re using your piece outside in the sunlight and open air, it’s likely going only to last a couple of hours.
What are the key differences between dry ice and regular ice?
So, dry ice is made up of solid carbon dioxide, and regular ice is made up of frozen water. Here are a couple of key differences between them:
- Dry ice is way colder than regular ice, with an internal temperature of around -109°F versus frozen water at 32°F. Due to this difference, dry ice has a whole lot more uses than regular ice, such as the transportation of super-sensitive medicines.
- Dry ice is a lot denser than frozen water.
- Dry ice is usually sold in blocks or as little pellets. Regular ice is usually sold in cubes.
- Dry ice turns into gas as it “ages” and is exposed to higher temperatures, whereas frozen water or ice melts back into the water.
What are some of the uses of dry ice in the food industry?
Dry ice gets used more than we would think in the food industry, here are a couple of interesting applications:
- Dry ice is used in food preservation. Foods that really need to be protected from spoiling are seafood, meat, poultry, and some dairy products. The impact on food safety, as well as the cost of potential spoilage, means that they are high-value perishable ingredients that need to be kept well-chilled during distribution. Dry ice does this effectively and is commonly used.
- Dry ice is a source of food packaging. When layered in with packaged food, dry ice creates a mini chilled atmosphere that stagnates the growth of harmful bacteria that can cause food poisoning. It, therefore, increases the shelf-life of that product.
- Dry ice is used in the carbonation of certain beverages. Have you ever dropped a piece of dry ice into a swimming pool and watched the bubbles rise up? When dry ice is added to a liquid, it turns into a gas and creates a fizz! This is how certain beers and sodas get their carbonation.
- Dry ice in the making of some ice creams. Adding dry ice in as part of the manufacturing of ice cream creates a cold environment that chills the ice cream ingredients and lets them freeze up. This quick freeze process is what leads to the silky smooth texture of some of the ice creams you know and love.
How to safely dispose of dry ice at home
As mentioned before, dry ice can lead to irritation and even skin damage if handled incorrectly. If you’re looking for a safe way to get rid of your block of dry ice, here are some points around how to do it safely:
- Place your piece of dry ice in a spot that is well-ventilated. Simply allow the dry ice to be exposed to air, and it will sublimate at around 5-10% per day. Do not apply any heat to it. Placing it in a sealed container will slow the process down. If you have a spot outside on a veranda or in the yard, this is ideal for your block.
- Wear gloves. These will protect you when handling your block of dry ice.
- Never leave dry ice where children, pets, or a neighbor might find it or unknowingly touch it. Make sure everyone in your home knows how to handle it.
Dry ice is likely to last about 10 days if stored correctly in a freezer or only a few hours to a day if kept in the open air. Have fun with your dry ice, and remember to protect yourself and those around you from skin damage and eye irritation from exposure to it.