UN-grade bags: tried and tested for hazardous products

Posted on 10 november 2021

The transportation and storage of dangerous goods calls for specific expertise. Not only the product needs to be protected from external factors. The environment and people working with the product throughout the entire supply chain need protection too.

It all starts with strict guidelines and a special bag. In comes the UN certified bag. In this article, we’ll explain what these are, how they’re tested and when you need them.

What are UN certified FIBCs?

UN Grade FIBCs align with United Nations specific regulations for handling, filling and transporting hazardous goods by sea, rail, and road.

What types of products are carried in UN grade bags?

They are produced especially to transport and store dangerous materials. For this, they go through a thorough and standardized testing procedure to make sure they are safe to use with products that fall into one of the following categories:

  • Class 4.1: Flammable solids, self-reactive substances, and desensitized explosives
  • Class 4.2: Substances liable to spontaneous combustion
  • Class 4.3: Substances that emit flammable gases when they come in contact with water
  • Class 5.1: Substances that oxidize
  • Class 5.2: Organic peroxides
  • Class 6.1: Toxic substances
  • Class 8: Corrosive substances
  • Class 9: Miscellaneous dangerous substances and articles

UN bags are therefore different from other ‘standard’ bags available on the market, even from the ones that are to be used with combustible materials. Read more about those types of bags here.

What are the norms when producing UN bags?

UN bulk bags are produced with High testing principles and come with specific labeling and naming prerequisites. Only when they tick all the boxes they can be sold as UN Bulk Bags. These are the types you can find on the market:

UN code

Type of FIBC


Flexible IBC for solids, filled or discharged by gravity (liquids and solids under pressure [>0.1 bar] are not permitted)


Woven PP fabric without coating or inner liner


Woven PP fabric, coated


Woven PP fabric with inner liner


Woven PP fabric, coated and with inner liner


Flexible IBC approved for packaging groups II and III


Flexible IBC approved for packaging groups III


As you can see, there are different packaging groups to keep in mind. These are identified based on how dangerous a product is. In the table below, you can see what groups there are.

Degree of Danger

Packing Group

UN Symbol

Max. Volume




1,5 m3




3 m3




3 m3


What tests are done on UN-grade bags?

The bags are tested with several safe working loads and go through a series of tests before they are approved for use. Some of the standards and quality parameters to follow when producing UN Bulk Bags are: 

  • Lift assessment: the bag is fillet with six times its maximum load. Then it is lifted to make sure it can carry its safe working load weight, and then some.
  • Tear test: while being filled with the maximum load, a small tear of 10 cm is made in the bag. Then it is filled to twice the maximum capacity. After leaving it to rest for a while, the bag is suspended with its safe working load for at least five minutes.
  • Stack test: while loaded with 1.8 times the maximum weight, the FIBC is stacked to see if it stays in place.
  • Drop test and topple test: filled to its maximum load, the bag is lifted to 80 to 120 centimeters and then dropped in an upright position. During the topple test it’s dropped on its side.
  • Recovery test: after the topple test, the bag is lifted again and put in an upright position to see how it recovers.

Find the right bag for your product

It’s crucial that you work closely together with your supplier to determine what type of bag you need for your product. If you want to know all about UN bags and are looking for the right one for your product, reach out to our team. 


Want to work towards sustainable supply chain management?

At Masterpack, we are continuously working towards better ways to pack and protect products. We proudly present our newest solution: Modified Atmosphere for FIBC’s. Download our latest whitepapers:

Testing and improving your packaging (1,6MB)
Modified Atmosphere in FIBC's (6,4MB)
Pest prevention and control in bulk packaging (2,8MB)
The Modified Atmosphere Packaging Process Whitepaper

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