Guide to UN Rating Codes

Packaging dangerous chemicals and product can be difficult due to safety requirements set in place by different nations. For this reason, it is important you know how to read the universal rating system (UN Ratings). This guide will give you the knowledge you need to effectively read the UN labeling system. In return, you should be able to properly pick from an abundance of UN rated containers while also abiding by the rules and restrictions that exist.

What Are UN Ratings?

For a quick overview of UN ratings before we break it down, watch the video below. It will introduce UN ratings, the symbols, and the importance of them for safety in packaging.

Developed as a set of standards by the United Nations, UN ratings are required for shipping and storing hazardous materials. A UN Rating is a series of letters and numbers that signify what a container is regulated to handle. This is determined through a series of tests that all containers must go through in order to be UN Rated. Current UN Regulations are enforced by the US Department of Transportation (D.O.T.). UN Ratings are located on the outside of a box.  

The packaging should be marked permanently (embossed) on the bottom and on either the side or the top. The bottom marks are known as the birth certificate of the container's original performance capability. 

In the early 1990s, the US Department of Transportation (DOT) adopted Performance Oriented Packaging (POP) to regulate international shipments of hazardous materials. Conflicting regulations between countries caused problems in shipping these materials, leading to the creation of UN Ratings by the United Nations to streamline regulations and ensure international compatibility.

When Do I Have to Use A UN Rated Container?

As stated earlier, the United Nations require UN ratings in order to make the shipping of hazardous materials safer and easier internationally. UN ratings help preserve the environment, demand safety for the people who are transporting the goods and allow efficiency across country lines. The following materials are all considered HAZMAT and require a UN rating in order to be shipped.

• Explosives
• Non-flammable gas
• Flammable gas
• Flammable liquid (*)
• Infectious substance
• Corrosives (*)
• Flammable solid (*)
• Oxidizers
• Organic peroxide
• Toxic materials
• Radioactive material

(*) - Most common hazard classes for UN certified classes. For more information on categorizing your hazardous material, use the HAZMAT Table.

The shipper is oblligated to comply with the regulations and determine the proper packaging. The shipper needs to ensure that the packaging is authorized, properly manufactured, assembled, and marked. It is important to know that any non-compliance results in a costly fine.

UN Rated labels are complicated due to the symbols and marking that go into it. If broken down, they become much easier to understand. Follow along as we break down the labels into a step by step process.

The first set of numbers following the UN symbol is known as the Packaging Identification Code. This section consists of the Package Type, Material, and Category.

1 - Drums/Pails

2 - Barrels

3 - Jerricans

4 - Boxes

5 - Bags

6 - Composite Packaging

7 - Pressure Receptacle

A - Steel

B - Aluminum

C - Natural Wood

D - Plywood

F - Reconstructed Wood

G - Fiberboard

H - Plastic

L - Textile

M - Paper, Multiwall

N - Metal except Steel/Aluminum

P - Glass, Porcelain, Stoneware

1 - Closed Head (one molded piece)

2 - Open Head (removable lid)

The first set of numbers following the UN symbol is known as the Packaging Identification Code. This section consists of the Package Type, Material, and Category.

X- High Hazard Level

• • Packing Group I, II, III

Y- Medium Hazard Level 

• • Packing Group II, III

Z- Low Hazard Level

• • Packing Group III

The ratio of the density compared to the density of water at a specific temperature and pressure.

Hydrostatic pressure test is a vapor pressure measured in kilopascals (kPa) rounded down to 1 decimal The results to one of the 5 tests required in UN rating.

It is important to note that the above 2 numbers are for labeling liquid material only. When labeling solids you would use the Maximum Gross Mass (kg) instead of Specific Gravity and then a Letter "S" instead of a number for the hydrostatic pressure test. (Refer to figure 1)

The Year of Manufacture refers to the year the packaging was manufactured.

The Country of Origin refers to the location where the package was manufactured.

The Manufacture Code is the code for UN certified agency or manufacturer. UN ratings tell you the description of the container as well as requirements to certify the product being packaged. It is important that all containers are labeled with the correct UN rating.

When to Use Food vs Liquid Products

The Cary Company helps our customers make the best decisions by using the proper UN ratings when packaging products. We also want tp help your business save time and money by reusing food or liquid containers that can effectively cross over.

Packing Group I  = X-Hazard Level= High Danger

If you have material that is packing group l you can use a X-rated container only. Because this is the highest rating, the lower ratings would not be able to withstand the danger level. There is no rating higher than Packing Group l.

Packing Group II = Y-Hazard Level= Medium Danger

If you have a material that is packing group ll you can use an X- or Y-rated container. Same instance for Packing Group ll, it states that your material needs at least a medium danger rated container meaning a great danger packaging would suffice.

Packing Group III= Z-Hazard Level= Low Danger

If you have material that is packing group lll you can use an X-, Y-, and Z-rated container. Because Packing Group lll says that your material needs the lowest danger rating the higher rating will be more than okay for your material. You can look at it as being over qualified.

The general rule of thumb for the crossover is that you can always pick a packaging group that is higher than what your material requires and still comply with the UN rating. this means that anything in the High Danger zone can only use the top leveling of packaging. The lowest danger product can use all three forms of HAZMAT packaging. 

Find Your UN Containers Today!

The United Nations requires UN ratings to make the shipping of hazardous materials safer and easier internationally. UN ratings help preserve the environment, demand safety for the people who are transporting the goods and allow efficiency across country lines. It is important to get UN rated packaging to ensure your products get shipped! 

If you have any questions The Cary Company would be happy to help you and provide further explanation. The Cary Product Sourcing Team will work with you to find the best packaging for you! -- Call 630.629.6600!