Difference Between Overpacks & UN Rated 4G Boxes

The use of Overpacks when shipping dangerous goods is often misunderstood. This article provides a better understanding of “What is an Overpack?”.

The term Overpack is defined by IATA as an enclosure used by a single shipper to contain one or more packages and to form one handling unit for convenience of handling and stowage. While the overpack itself isn’t UN-rated, it is meant to contain one or more UN-rated packaging. From time to time, I’ll receive a call from a customer asking for an overpack box to ship their dangerous goods. Sometimes, as I ask follow-up questions, we determine that they are actually looking for a UN-rated 4G box, and not an overpack. That’s why it is crucial to understand the difference between a UN-rated box and an Overpack Box.

Overpack Box vs 4G Box

When shipping dangerous goods, it’s crucial to ensure proper packaging and containment. As you may know, there are times when UN rated packaging is required to ship your dangerous goods. As mentioned in my previous article, this means that the packaging has been UN tested and has a UN specification marking on it.

However, there may be other times where you are shipping an already UN tested packaging, such as a drum or jerrican, and you want to add a little bit of protection during the shipping process. One solution for this would be the use of overpack boxes for your UN-rated containers. Overpack boxes provide an additional layer of protection. For example, we sell an Overpack box called the PK-UPS below.

This overpack box is not UN-rated and is not considered a 4G box, so you won’t see a UN Specification code printed on it. However, if you have a 5-gallon plastic or metal drum that is already UN rated, you can use this box to provide extra protection during your shipment and already has the required overpack marking and orientation arrows printed on it. These boxes come with or without die-cut handles. Don’t forget when using this box, all hazard class labels and markings must also be represented on the outside of the box as well as the inside UN rated container.

Do you have questions about Overpacks? Take a look at our FAQ or contact our team of experts at 855.734.5469 or send us an email, we’re happy to help.