Reference
UN31HA1/Y, character by character.
The marking on an IBC data plate is one of the most misread pieces of information in the trade. It is not a quality mark, it is not a food certification, and it does not stay valid on its own. It is a transport approval for a specific assembly that depends on periodic inspection and testing.
The short answer
UN — UN Recommendations. 31 — IBC for liquids. H — plastic inner receptacle. A — steel outer. 1 — rigid inner receptacle. Y — packing groups II and III. It covers the whole assembly, depends on periodic inspection and testing recorded on the plate (check current regulations for intervals), and says nothing about food safety.
The code
Each character, decoded.
| Element | Position | Means | Other values you may see |
|---|---|---|---|
| UN | Prefix | Packaging marked as conforming to the UN Recommendations for dangerous goods | — |
| 31 | IBC type | IBC for liquids | 11 = rigid, solids, gravity discharge; 21 = solids, pressure discharge |
| H | Inner receptacle material (composite) | Plastics | For composite IBCs the inner is normally plastics |
| A | Outer material (composite) | Steel | B = aluminium, N = other metal, H = plastics, C = natural wood, D = plywood, F = reconstituted wood, G = fibreboard |
| 1 | Category (composite) | Rigid plastic inner receptacle | 2 = flexible plastic inner receptacle |
| /Y | Packing group | Approved for packing groups II and III | X = groups I, II and III; Z = group III only |
| Country code | After the code | State that authorised the marking | For example USA, D, GB, F |
| Manufacturer code | After country | Name or symbol of the manufacturer or approval holder | Varies |
| MM/YY | Date | Month and year of manufacture | — |
| Stacking load | kg | Stacking test load | Varies by design |
| Max gross mass | kg | Maximum permissible gross mass, container plus contents | Varies by design |
| Test pressure | kPa | Hydraulic test pressure for liquid designs | Varies by design |
What the marking covers
A design type that has passed a defined series of tests — such as drop, stacking, hydraulic pressure, leakproofness and lift tests, depending on the IBC type. The approval is granted to a design, and units built to that design may carry the mark.
Crucially, the approval covers the assembly. The bottle alone is not approved; the cage alone is not approved. It is the combination, in the tested configuration, with the tested components. This is why arbitrary component swapping can take a unit outside its approval, and why re-marking after a rebuild is a regulated activity rather than a stamping exercise.
What it does not cover
- Food contact suitability — a different set of rules entirely
- Chemical compatibility with your specific product
- Cleanliness or prior-contents history
- Current condition, if inspections or tests are out of date
- Suitability for storage as opposed to transport
Inspection and test dates
This is where much non-compliance happens, and it happens quietly because the marking looks exactly the same after the dates run out.
| Event | What is generally required |
|---|---|
| Periodically | Leakproofness testing and inspection at the intervals set by current regulations, with dates recorded on the unit |
| After repair | Inspection and testing appropriate to the work before the unit is used again for dangerous goods |
| After component change | The assembly may fall outside the approved design type and may need re-marking |
| Before every use | Check the unit is in date, undamaged and suitable for the product |
Three practical rules
- Read the dates, not just the stamp. A marking without current inspection and test dates is a historical record.
- Ask explicitly at purchase. “Is it UN marked?” and “when was it last inspected and tested?” are two different questions and you need both answers.
- Keep a register. Record serials, codes and test dates for every unit you ship dangerous goods in, so nothing drops out of date unnoticed.
Decision
Do you actually need one?
A general guide. The question is about transport regulation, not about how dangerous the liquid seems — and the details depend on current regulations.
| Situation | UN marked? | Why |
|---|---|---|
| Shipping a regulated dangerous good | Generally yes, with inspections in date | It is a transport packaging requirement |
| Moving product within your own site | Often not | May not count as regulated transport; check current regulations |
| Storing chemistry in place | Not for transport purposes | Storage is not transport; other rules may apply |
| Shipping non-regulated product, such as water | Generally no | No dangerous-goods classification, no packaging requirement |
| Exporting | Often yes | Other countries' rules may apply; check before shipping |
| Your customer specification demands it | Yes | Contractual, regardless of the regulatory position |
| Shipping regulated waste | Often yes | Waste transport has its own requirements; check current regulations |
UN marking questions
What does UN31HA1/Y mean?
Read it in pieces. UN means the packaging was marked as conforming to the UN Recommendations on the Transport of Dangerous Goods. 31 means an IBC for liquids. HA means a composite IBC with a plastic (H) inner receptacle and a steel (A) outer. The 1 means the inner receptacle is rigid. Y means the design was approved for packing groups II and III. Together: a composite IBC for liquids with a rigid plastic inner and a steel outer, approved for medium- and low-danger goods.
Does a used IBC tote keep its UN rating?
Only if it stays within the approved design type and its periodic inspections and tests are kept up to date as the regulations require. The marking belongs to the complete assembly — bottle, cage and base together — so swapping components can take it outside the approved design. A marking on a plate is evidence of a past approval and tests, not proof the unit is currently fit to ship dangerous goods.
How often do UN-marked IBCs need retesting?
IBCs used for dangerous goods are subject to periodic inspection and leakproofness testing at intervals set by the transport regulations, and the dates are recorded on the unit. The intervals and requirements are set by regulators and can change, so check current regulations for your mode of transport. A unit that is out of date is not a compliant package, whatever the original marking says.
Do I need a UN-marked tote for my product?
Generally, if the product is regulated as a dangerous good for transport and you are shipping it, you need packaging approved for it with its inspections in date. If you are storing in place, or shipping something not regulated for transport, you may not. Exemptions and details vary, so check current regulations. The question is about transport regulation, not about how hazardous the liquid feels.
Is a UN-marked tote also food grade?
They are unrelated. UN marking concerns the safe transport of dangerous goods; food grade concerns material suitability and contamination history. A UN-marked tote may or may not be suitable for food, and a food-grade tote may or may not be UN marked. For food use, ask the supplier for documentation and check current regulations.
Reading a plate
A typical marking, line by line.
What you will usually find on an IBC data plate. The code is the part everybody reads first; the dates are often the part that matters most.
| Line on the plate | Means | Changes when |
|---|---|---|
| Packaging code, such as UN 31HA1/Y | IBC type, materials, category and packing groups | Not for that design type |
| Month and year of manufacture | When the unit was built | Not |
| State authorising | Country whose authority authorised the marking | Not |
| Manufacturer or approval code | The manufacturer or approval holder | May change on re-marking |
| Stacking test load | Load used in the stacking test | Not |
| Maximum permissible gross mass | Container plus contents | Not |
| Test pressure | Hydraulic test pressure for the design | Not |
| Date of last leakproofness test | Most recent leakproofness test | Each time it is retested |
| Date of last inspection | Most recent periodic inspection | Each time it is inspected |
| Inner receptacle markings | Details of the bottle itself | On rebottling |
Adjacent rules
What else might apply to your movement.
UN packaging is one requirement among several. These are the kinds of rules that most often turn up alongside it. Check current regulations for each.
| Area | Applies when | Concerns | Relationship to UN marking |
|---|---|---|---|
| US DOT hazardous materials rules | Transporting dangerous goods in the US | Packaging, marking, labelling, documentation | Based on the UN system |
| ADR | Road transport in Europe | As above, European implementation | Same marking system |
| IMDG Code | Sea freight | Packaging plus stowage and segregation | Same marking system, extra stowage rules |
| IATA Dangerous Goods Regulations | Air freight | Air-specific packaging rules | Different and often stricter |
| Hazardous waste rules | Shipping hazardous waste | Manifests, container condition and marking | Often require approved packaging |
| Flammable liquid storage rules | Storing flammable liquids | Quantities, location and fire protection | Separate from transport marking |
| Oil spill prevention rules | Storing oil above certain amounts | Containment and planning | Separate |
| Food contact rules | Food or beverage use | Material composition and history | Completely unrelated |
Testing
What a design type has to pass.
The kinds of tests behind the marking, so you know what it is and is not evidence of. Exact procedures and criteria are set by the regulations.
| Test | In general terms | Tells you |
|---|---|---|
| Bottom lift | Lifted from underneath by forks | Fork handling is survivable |
| Top lift | Lifted by designed lifting points, where fitted | Crane and hoist handling |
| Stacking | Loaded with a superimposed test load | Where the stacking load figure comes from |
| Leakproofness | Tested with internal air pressure | Seals and closures |
| Hydraulic pressure | Filled and pressurised | The test pressure figure on the plate |
| Drop | Dropped onto a rigid surface | Handling accidents |
| Vibration | Vibrated on a test platform | Road transport |
Practical checks
Auditing your own totes' markings.
Eight steps for anyone shipping regulated product in IBCs.
| # | Step | Looking for |
|---|---|---|
| 1 | Confirm which units need a marking at all | Units used to ship regulated dangerous goods |
| 2 | Locate the data plate on each | Usually attached to the cage or frame |
| 3 | Read the packaging code | The IBC code and the packing-group letter — /Z where /Y was assumed is a common surprise |
| 4 | Read the date of manufacture | Month and year |
| 5 | Read the last leakproofness test date | Whether it is within the interval the regulations require |
| 6 | Read the last inspection date | Whether it is within the interval the regulations require |
| 7 | Check max gross mass against your product | The kg figure on the plate |
| 8 | Record all of it in a register | Serial, code and all dates |
Looking for UN-marked totes? Request a free, no-obligation quote and we will match your request with a partner supplier in our network. Ask the supplier for the marking and test dates on the units offered, and check current regulations for your shipment.