Understanding UN Ratings on IBC Totes: What the Codes Mean
Understanding UN Ratings on IBC Totes: Decoding the Markings
Every IBC tote manufactured for transporting hazardous materials carries a standardized United Nations marking stamped or embossed on the container. These markings are not arbitrary — they communicate critical information about the tote's design, testing, and approved uses. Understanding UN ratings is essential for regulatory compliance, safety, and selecting the right container for your application.
This guide breaks down every element of UN IBC markings so you can read them with confidence.
The UN Symbol
All certified containers begin with the UN emblem — a circle containing the lowercase letters "un" or the official UN packaging symbol. This symbol confirms that the container was manufactured and tested according to the United Nations Recommendations on the Transport of Dangerous Goods. Without this symbol, the container is not certified for hazardous material transport.
Container Type Codes: 31HA1 and 31HZ1
Immediately following the UN symbol is a code that identifies the container type. For IBC totes, the most common codes are:
- 31HA1: Rigid plastic IBC with structural equipment (metal cage), designed for liquids. The "31" indicates it is an IBC for liquids. "H" designates a rigid plastic inner container. "A" means it has structural equipment (the metal cage frame). "1" indicates it is a non-removable rigid inner container.
- 31HZ1: Composite IBC with a rigid plastic inner container and an outer casing. The "Z" indicates a composite construction. These totes have additional outer protection beyond the standard metal cage.
- 31HZ2: Similar to 31HZ1 but with a flexible inner container — less common in standard IBC totes.
- 21HA1: Rigid plastic IBC for solids, with structural equipment. The "21" indicates solid contents rather than liquids.
For most water, chemical, and industrial applications, you will encounter the 31HA1 designation. This is the standard 275-gallon (1,000-liter) IBC tote with an HDPE inner bottle and welded steel cage.
Packing Groups: I, II, and III
Hazardous materials are classified into three packing groups based on the degree of danger they present:
| Packing Group | Danger Level | Examples | IBC Requirements |
|---|---|---|---|
| I | Great danger | Fuming nitric acid, allyl alcohol | Highest construction standards. Rarely used with standard IBC totes — most PG I materials require specialized containers. |
| II | Medium danger | Acetic acid, acetone, many solvents | Moderate construction standards. Many reconditioned IBC totes are rated for PG II. |
| III | Minor danger | Cleaning solutions, paints, adhesives | Standard construction. Most commonly available rating for new and used IBC totes. |
The packing group rating on an IBC tote tells you the maximum hazard level it is certified to contain. A tote rated for Packing Group II can also carry Packing Group III materials, but not Packing Group I. A tote rated only for Packing Group III cannot be legally used for PG II substances.
Testing Standards
UN-rated IBC totes must pass a battery of performance tests before certification. These tests simulate real-world transport conditions:
Drop Test
The filled IBC is dropped from a specified height onto a rigid, non-resilient surface. For Packing Group II, the drop height is 1.2 meters (approximately 4 feet). For Packing Group III, the drop height is 0.8 meters (approximately 2.6 feet). The tote must not leak after the drop. This test is performed on each of the most vulnerable orientations — bottom drop, top drop, and side drop.
Stack Test
The filled IBC is subjected to a superimposed load equivalent to the maximum stacking weight for a period of at least 28 days at 40°C (104°F). This simulates the stress of being stacked during storage and transport. The tote must not deform to the point of leaking or becoming structurally unsafe. Standard IBC totes are typically rated for a maximum stack load of 2-3 totes high when filled to capacity.
Hydraulic Pressure Test (Leakproof Test)
The IBC is pressurized internally using air or hydraulic fluid to a minimum of 20 kPa (2.9 psi) above ambient or the vapor pressure of the contents at 55°C, whichever is greater. The container must not leak or show permanent deformation. This test verifies the integrity of all seals, gaskets, and joints.
Bottom Lift Test
The filled IBC is lifted from beneath by a forklift engaging the pallet base. The container is held in the lifted position for five minutes. No permanent deformation or damage that renders the IBC unsafe for transport should occur. This verifies that the pallet base can support the full weight of the contents during normal handling.
Date Codes
The UN marking includes the date of manufacture in MM/YYYY format (e.g., 06/2023 indicates June 2023). This date is critical because UN certification is time-limited:
- New IBC totes: Valid for 5 years from the date of manufacture for transporting hazardous materials.
- After 5 years: The tote must be inspected, retested, and recertified (if it passes) before it can continue to be used for hazardous material transport.
- After 2.5 years: Some regulations require a visual inspection at the 2.5-year mark.
For non-hazardous materials (water, non-regulated chemicals, agricultural products), the date code is less critical from a regulatory standpoint but still indicates the age and expected remaining lifespan of the HDPE material.
Manufacturer Markings
The UN marking includes the manufacturer's name or registered symbol, allowing traceability back to the production facility. Major IBC manufacturers include Schutz, Mauser (now MAUSER Packaging Solutions), Greif, and Werit. The manufacturer marking ensures accountability and provides a reference if warranty claims or product recalls arise.
Country of Origin
A country code (e.g., "USA," "D" for Germany, "F" for France) identifies where the IBC was manufactured. This is important because different countries have slightly different implementation standards under the UN framework. For transport within North America, Department of Transportation (DOT) regulations (49 CFR) govern the use of UN-rated containers. In the European Union, the ADR (European Agreement concerning the International Carriage of Dangerous Goods by Road) applies.
Reading a Complete UN Marking: Example
A typical complete UN marking on an IBC tote might read:
UN 31HA1/Y/05 23/USA/SCHUTZ/10123
- UN: Certified under UN standards
- 31HA1: Rigid plastic IBC with metal cage, for liquids
- Y: Approved for Packing Group II and III
- 05 23: Manufactured May 2023
- USA: Manufactured in the United States
- SCHUTZ: Manufacturer name
- 10123: Production serial or batch number
The letter codes for packing groups are: X = PG I, II, and III; Y = PG II and III; Z = PG III only.
Recertification Requirements
After the initial 5-year certification period, an IBC tote must undergo recertification to continue being used for hazardous materials transport. The recertification process includes:
- External visual inspection for cracks, dents, corrosion, or UV degradation
- Internal inspection for contamination, staining, or material degradation
- Valve and gasket inspection and replacement if necessary
- Hydraulic pressure test to verify continued leakproof integrity
- Verification that all original markings are legible
- Addition of a recertification marking including the recertifier's name and date
Recertification can extend the usable life of an IBC by an additional 2.5 years per cycle. However, most regulations limit the total service life of an HDPE IBC to approximately 10 years for hazardous material use, regardless of recertification status, due to long-term UV degradation and material fatigue.
Why UN Ratings Matter Even for Non-Hazardous Uses
Even if you plan to use your IBC tote only for water or non-regulated materials, UN ratings provide valuable information. A tote rated for Packing Group II has been built and tested to higher standards than one rated only for PG III — it will generally be more durable and longer-lasting. The date code tells you how old the HDPE material is, which directly affects its remaining useful life. The manufacturer marking helps you identify quality brands versus unknown producers.
For help selecting the right UN-rated IBC tote for your specific application, reach out to IBC Totes Niagara Falls. We can walk you through the markings on any tote in our inventory and match you with the right container for your needs.