September 21, 2020

How to Insulate a Shipping Container

“Is it going to be OK in this?”

It’s a common question when shipping any valuable item, but even more so when that item is temperature sensitive. Food, plants, and pharmaceuticals are a few of the most common temperature-sensitive products that require proper preparation and handling to arrive safely to their destination. You can help mitigate risks of damage by properly insulating the container before shipping. Here are a few proven strategies and ideas to consider.


Properly insulating a shipping container starts with the packaging itself. Shipping stores usually offer thermostat-controlled packaging that regulates temperatures inside the container, keeping products at a safe temperature over long periods of time. These containers are appropriate for extremely sensitive products such as medical shipments.

For less sensitive materials or shorter travel times, other packaging options include a combination of foam coolers and corrugated boxes.

EPS foam offers a lightweight, cost-effective insulated shipping solution that’s commonly used for frozen materials. PUR foam offers more insulation but higher costs than EPS foam. PUR foam coolers are commonly used for longer transits. All foam containers should be placed in corrugated boxes for proper protection.


Once you’ve decided which container is the best for your shipment, you can start evaluating coolants or refrigerants to add to the container. These are the secondary insulating products that support the packaging in regulating temperature.

The most common shipping coolant is dry ice, which is the solid form of carbon dioxide. Dry ice is cooler than traditional ice and maintains its form for longer periods of time. Never use traditional ice as a coolant. The extremely low temperatures of dry ice make it a great option for shipping frozen materials, but also pose a risk if not handled appropriately. Per regulations, there can be no more than 4.5lbs of dry ice used.

Another common coolant used in shipping are gel packs. These reusable packs are effective for items that must be refrigerated, but not frozen. Gel packs are most effective when secured in place and covered so as to avoid contact with the item.

For the highest insulation value, you can use phase change material (PCM). PCM is a substance that’s capable of transitioning between solid, liquid, and gas based on temperature. PCM provides the superior temperature control to dry ice or gel packs and is commonly used for long transits and the most temperature sensitive products.

Insulating Cushion

The final step to insulating a shipping container is adding an insulating cushion. This can be done by adding insulating bubble wrap around the item and filling in any gaps in the container with foam or foam peanuts. This adds a final layer of insulation while also adding a layer of damage protection.

Now that your shipping container is properly insulated, it’s time to take it to a reputable shipping carrier. When dropping off your container, please let us know that you are shipping a package with coolant material so we can ensure proper precautions are taken. PostalAnnex has the experience and expertise to safely deliver your temperature-sensitive products at minimal cost. With more than 30 years of cold chain freight experience, you can rest assured that your package will arrive in the condition it left. Contact your PostalAnnex expert today for more information.