How long will dry ice keep things frozen? When it comes to keeping items frozen during travel, emergencies, or long-term storage, dry ice is often the go-to solution. This is a common question for anyone planning to use dry ice for food preservation, shipping, or even creating special effects.

Whether you’re using dry ice to ship medical supplies, store frozen foods during a camping trip, or simply preserve your ice cream during a power outage, understanding how long dry ice lasts is crucial for effective use.

In this article, we’ll cover everything you need to know about the duration of dry ice’s freezing power, including its efficiency in coolers, freezers, refrigerators, during shipping, and in Styrofoam containers. Plus, we’ll discuss the factors that impact its longevity, the best storage methods, safety precautions.

What Is Dry Ice and How Does It Work?

Dry ice is solid carbon dioxide (CO₂), which is a substance that’s colder than regular ice, at a temperature of about -109.3°F (-78.5°C). Unlike regular ice, dry ice doesn’t melt into a liquid; instead, it sublimates, turning directly from a solid to a gas. This unique property makes dry ice particularly effective for keeping things frozen without creating any mess or moisture, which can be problematic with regular ice.

Because of its extreme cold, dry ice is ideal for preserving items like perishable foods, pharmaceuticals, and even for use in theatrical productions to create a fog effect.

How Long Will Dry Ice Keep Things Frozen?

The main question is: how long will dry ice keep things frozen? The answer can vary based on several factors, including the amount of dry ice, the type of container used, and the temperature of the surrounding environment. Here’s a breakdown of how long dry ice typically lasts in different situations:

• In a Cooler: Dry ice can typically last 18 to 24 hours in a well-insulated cooler. The cooler’s insulation plays a crucial role in extending the duration. In a basic cooler, dry ice will sublimate faster, so you’ll want to ensure the cooler is as insulated as possible.
• In a Styrofoam Cooler: Styrofoam is a great insulator, so dry ice can last up to 24 hours or more in a Styrofoam cooler. If you want to keep the contents frozen longer, try layering dry ice with regular ice or insulating the container further.
• In a Freezer: Dry ice is not ideal for long-term freezing, but in a pinch, it can help keep food frozen during power outages. Typically, dry ice will keep things frozen in a freezer for 12 to 24 hours, depending on the size of the freezer and the amount of dry ice used.
• In a Fridge: If you’re storing items in a fridge, dry ice can keep them frozen for up to 18 hours or so. However, you’ll need to make sure the dry ice is placed at the top of the food to keep everything below freezing.

How Long Does Dry Ice Last When Shipping?

Shipping frozen items, especially perishable goods like food or pharmaceuticals, often requires the use of dry ice. The duration that dry ice will keep things frozen during shipping depends on factors like the type of shipping container, the amount of dry ice used, and the environmental conditions.

Typically, dry ice will last 24 to 48 hours when used in properly insulated shipping containers. This is enough time to ensure that items stay frozen during transit, especially when using courier services like FedEx or UPS that have specific guidelines for shipping with dry ice.

If you’re shipping sensitive items, make sure to follow the packing guidelines, including using double insulation and allowing room for air circulation to prevent the buildup of gas pressure.

How Long Will Dry Ice Keep Things Frozen in the Freezer?

Dry ice is great for short-term use in the freezer, such as during power outages, but it isn’t a long-term solution for keeping your food frozen. Typically, dry ice will keep things frozen in the freezer for 12 to 24 hours, depending on the size of the freezer, the amount of dry ice, and how well the freezer is sealed.

To get the most out of dry ice in your freezer:

• Place it at the top of the freezer to ensure that cold air flows downward.
• Minimize freezer opening to prevent the warm air from reducing the effectiveness of the dry ice.
• Use insulated materials inside the freezer to reduce the sublimation rate of dry ice.

How Long Will Dry Ice Keep Things Frozen in the Fridge?

Using dry ice in the fridge is a great way to keep perishable items frozen for a short period, especially when traveling or during emergencies. Dry ice will typically keep things frozen in the fridge for up to 18 hours, though this can vary depending on the insulation and size of the fridge.

To maximize efficiency:

• Use insulated coolers or thermal blankets to wrap the items and slow the sublimation process.
• Keep dry ice away from direct contact with plastic items, as extreme cold can cause cracking.
• If possible, keep the fridge in a cool, shaded area to help extend the freezing time.

How Long Will Dry Ice Keep Breast Milk Frozen?

For parents, keeping breast milk frozen during travel is essential. Dry ice can be a lifesaver in this scenario, especially if you’re traveling for an extended period or need to transport it without access to a freezer.

Dry ice will typically keep breast milk frozen for 18 to 30 hours, depending on the amount of dry ice used and the quality of insulation in the cooler. To ensure safety and optimal storage:

• Use a dedicated cooler for the breast milk.
• Place dry ice on top of the containers to maintain freezing temperatures.
• Avoid airtight containers to prevent pressure buildup.

Where to Buy Dry Ice

Finding dry ice is relatively easy, but availability can vary based on location. Common places to buy dry ice include:

• Grocery stores like Walmart or Safeway often carry dry ice in the frozen food section.
• Ice suppliers or industrial gas companies like Airgas or Praxair.
• Some gas stations and party supply stores may also sell dry ice.

It’s always a good idea to call ahead to ensure availability, as dry ice is not always in stock.

How to Store Dry Ice Safely

Proper storage is key to maximizing the lifespan of dry ice and ensuring safety. Here are some tips for storing dry ice:

• Use insulated coolers, but never airtight containers. Dry ice sublimates into CO₂ gas, and if stored in a sealed container, pressure can build up and cause an explosion.
• Store dry ice in a well-ventilated area, as the sublimation process releases CO₂ gas, which can be dangerous in an enclosed space.
• Use gloves or tongs when handling dry ice to avoid frostbite or injury.

Safety Tips for Handling Dry Ice

While dry ice is incredibly useful, it’s essential to handle it with care to avoid injuries or accidents. Here are some important safety tips to keep in mind:

• Always use gloves or tongs: Dry ice is extremely cold and can cause severe frostbite if it comes into direct contact with your skin. Always use thick gloves or tongs when handling dry ice to protect your hands.

• Ensure fresh air circulation: Dry ice sublimates into carbon dioxide gas, which can be dangerous if it builds up in an enclosed space. Always use dry ice in a well-ventilated area to prevent the risk of suffocation. Never store dry ice in a sealed or airtight container.

• Keep away from pets/children: Due to its extreme cold, dry ice can cause serious injuries to pets and children. Make sure to keep dry ice out of reach of little ones and animals to avoid accidents.

• Never store in airtight containers: As dry ice sublimates, it releases carbon dioxide gas, which can cause pressure to build up in airtight containers. This could lead to an explosion. Always store dry ice in ventilated containers and never seal it inside airtight boxes or jars.

Conclusion

Dry ice is a powerful tool for keeping things frozen during travel, shipping, and emergencies. However, the duration of dry ice’s freezing power depends on several factors, including the type of container, the amount used, and the surrounding conditions. Whether you’re shipping items, preserving food, or keeping breast milk frozen, understanding how long dry ice lasts is crucial for ensuring the success of your freezing efforts.

By following the tips outlined above, including using the right containers and handling dry ice with care, you can maximize its efficiency and keep your items frozen for as long as possible. Always remember to prioritize safety and proper storage to make the most of dry ice’s unique properties.