Tips & GuidesJanuary 14, 20269 min read

Understanding IBC UN Ratings and Markings: A Complete Decoder Guide

Every IBC carries a stamped UN marking that tells you exactly what it is, what it can hold, and how old it is. Learn how to read and interpret every element of the IBC data plate.

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The IBC Data Plate: Your Container's Identity Card

Every IBC manufactured for the transport of regulated materials carries a permanent marking — typically a metal plate riveted to the cage or embossed directly into the HDPE bottle. This marking follows the United Nations format established by the UN Sub-Committee of Experts on the Transport of Dangerous Goods, and it contains a wealth of information about the container's specifications, capabilities, and history.

Learning to read this marking is essential for anyone who buys, sells, ships, or stores materials in IBC containers. Here's a complete guide.

The UN Marking Format

A typical IBC marking looks like this:

UN 31HA1/Y/0124/USA/SCHTZ-1234/5000/1500

Let's decode each element.

Element 1: UN Symbol + IBC Type Code

UN 31HA1

UN: Indicates the container meets United Nations performance standards
31: IBC category — "3" means rigid IBC; "1" means intended for liquids
H: Container material — "H" means composite (plastic inner with outer framework)
A: Inner container material — "A" means plastic (specifically HDPE for most IBCs)
1: First use / new at time of marking. "2" would indicate reconditioned

Other type codes you may encounter:

31A = Rigid plastic IBC (no outer framework)
31B = Rigid metal IBC (aluminum)
31N = Rigid metal IBC (steel, other than stainless)
21H = Flexible composite IBC

Element 2: Packing Group

Y

This letter indicates the highest hazard packing group the IBC is certified for:

X: Packing Groups I, II, and III (most hazardous — approved for all groups)
Y: Packing Groups II and III (moderate and low hazard)
Z: Packing Group III only (low hazard)

Most composite HDPE IBCs are rated "Y," meaning they can carry Packing Group II and III materials. Packing Group I materials (the most dangerous) typically require metal IBCs or drums.

Element 3: Date of Manufacture

0124

This is the month and year of manufacture: 01 = January, 24 = 2024. This date is critical because the DOT imposes a maximum service life of 5 years from the date of manufacture for composite IBCs used in hazardous materials transport (49 CFR 180.352).

Element 4: Country of Manufacture

USA

The country where the IBC was manufactured and certified.

Element 5: Manufacturer/Approval Number

SCHTZ-1234

The manufacturer's name or code and the competent authority approval number. "SCHTZ" is Schutz Container Systems, one of the world's largest IBC manufacturers. Other common manufacturers include Mauser (now MAUSER Packaging Solutions), Greif, and Time Technoplast.

Element 6: Maximum Capacity

5000

The maximum gross mass in kilograms when fully loaded (container + contents). For a standard 275-gallon IBC, this is typically 5,000 kg for "Y" rated containers.

Element 7: Tare Weight

1500

The tare weight in kilograms (weight of the empty container). This figure, combined with the maximum gross mass, determines the maximum net payload.

Additional Markings

Beyond the primary UN marking, you may find additional stamps or plates:

Reconditioner Marking

If the IBC has been reconditioned, a separate marking identifies the reconditioner:

REC/USA/RC-5678/0326

REC: Indicates reconditioning was performed
USA: Country where reconditioning occurred
RC-5678: Reconditioner's registration number
0326: Date of reconditioning (March 2026)

Stacking Test Mark

A symbol or text indicating the maximum stacking load the IBC can withstand. Common format: "STACKING TEST LOAD: 6400 kg"

Hydraulic Pressure Test

For IBCs tested for leakproofness: "TESTED AT 20 kPa" or similar notation indicating the pressure test level.

How to Use This Information

When Buying

Check the manufacture date. For hazmat transport, don't purchase IBCs older than 5 years
Verify the packing group rating matches your intended contents
Confirm the UN type code matches what you need (31HA1 for standard composite IBCs)
Look for the reconditioner marking if buying reconditioned units

When Selling

Document the manufacture date and UN markings in your listing
IBCs with recent manufacture dates and clean markings command higher buyback prices
Reconditioned IBCs with proper marking are more valuable than unreconditioned units

When Shipping

Ensure the IBC marking matches the hazmat shipping papers
Verify the manufacture date is within the 5-year service life for regulated shipments
Confirm the packing group rating is appropriate for the material being shipped

Common Questions About IBC Markings

Can I use an IBC with an expired manufacture date? For non-hazmat applications, yes. The 5-year limit applies only to DOT-regulated hazardous materials transport. For water storage, non-hazardous chemicals, or food ingredients (with proper cleaning), the IBC can continue in service as long as it passes visual inspection.

What if the marking plate is missing or illegible? An IBC with an unreadable marking cannot be used for hazmat transport. For non-regulated applications, you can still use it, but you won't know the packing group rating or manufacture date.

Need help interpreting your IBC markings? Send us a photo and our team will decode it for you.

IBC Tanks Recycle Team
Published January 14, 2026
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