The UN code on the data plate — e.g. 31HA1/Y/04 26/D/BAM 1234-ACME/5500/1600 — is your IBC's type-approved dangerous goods certification under ADR chapter 6.5: 31 stands for an IBC for liquids, H for the plastic inner receptacle, A for the steel outer packaging (tubular steel cage), 1 for the rigid inner receptacle, Y for packing groups II and III. It is followed by the month and year of manufacture, the state of approval, the approval number including the manufacturer, the stacking test load in kg and the maximum permissible gross mass in kg.
If you're a buyer or logistics manager who has to decide whether an IBC on offer is permitted for your medium, this is exactly the line you need — and you need to know what it does not tell you. We'll cover both here.
The UN code, mark by mark
The marking is mandated by ADR 6.5.2.1.1, must be durable and legible, and starts with the UN packaging symbol. The following example is fictitious but typical of a German composite IBC:
| Mark (example) | Meaning | What you need to know |
|---|---|---|
| 31 | Design type: IBC for liquids | 11 = solids (filled and discharged by gravity), 21 = solids filled or discharged under a pressure > 10 kPa, 31 = liquids (ADR 6.5.1.4) |
| H | Inner receptacle material: plastic | Composite IBCs carry two letters: the first for the inner receptacle, the second for the outer packaging |
| A | Outer packaging material: steel | B = aluminium, N = other metal. An all-metal IBC carries a single letter (e.g. 31A), a rigid plastic IBC 31H1/31H2 |
| 1 | Rigid inner receptacle | 2 = flexible inner receptacle. The classic composite IBC with an inner bottle in a steel cage is always 31HA1 |
| Y | Approved for packing groups II and III | X = PG I–III (applies to solids IBCs only — PG I liquids are not permitted in IBCs at all), Z = PG III only. Your medium's packing group is listed in ADR Table A |
| 04 26 | Month and year of manufacture of the IBC | For the inner bottle's 5-year limit, the bottle's own date counts, not this one (see below) |
| D | State of approval | Country code of the state that granted the approval |
| BAM 1234-ACME | Approval number and manufacturer | In Germany, design type approvals are issued by BAM (the German Federal Institute for Materials Research and Testing) |
| 5500 | Stacking test load in kg | 0 = not stackable. The test load is 1.8 times the stacking load permitted in service (ADR 6.5.6.6) |
| 1600 | Maximum permissible gross mass in kg | Together with the capacity, this caps how dense your medium may be |
Additional markings on the data plate
Alongside the UN code, ADR 6.5.2.2 requires further information: capacity in litres, tare mass, test pressure where applicable — and above all the date of the last leakproofness test and the date of the last inspection. Since 2011 a stacking pictogram showing the stacking load permitted in use has been added (ADR 6.5.2.2.2). The plastic inner receptacle additionally carries its own date of manufacture (ADR 6.5.2.2.4), often as an embossed date clock — on used and rebottled IBCs this is the detail that decides everything.
What the UN code does NOT tell you — the part that costs money
The UN marking is not a blank cheque. It proves that the design type has passed the tests — not that the IBC suits your medium. Four things you must check on top:
- Medium and packing group: ADR Table A assigns your substance an IBC packing instruction (e.g. IBC02) and a packing group. A Y-marked IBC covers PG II and III — for a PG I substance it is off limits, no matter how new it is.
- Density: quick check: maximum permissible gross mass minus tare weight, divided by the capacity. At 1,600 kg gross and ~65 kg tare, a 1,000-litre IBC can nominally carry media up to a density of ~1.5 — and on top of that, the design type must be tested for that density. That is stated in the manufacturer's approval certificate, not in the code.
- Chemical compatibility: HDPE inner bottles are qualified for groups of substances via standard liquids (ADR 6.1.6) and the assimilation list (ADR 4.1.1.21). Whether your specific medium is covered can only be settled by the approval certificate or the manufacturer.
- Gasket and fittings: whether the 2-inch outlet valve is fitted with a PCP, EPDM or Viton (FKM) gasket appears nowhere in the UN code — EPDM swells on contact with oils and diesel, where FKM is required. The 225 mm filling opening (instead of the 150 mm) also has to be specified separately.
And: UN does not mean FOOD. Food-grade suitability comes via a food-grade inner bottle with a Declaration of Compliance under Regulation (EC) No 1935/2004 and Regulation (EU) No 10/2011 — an entirely separate matter alongside the dangerous goods approval. More on this: Food-grade IBC containers.
The deadlines: 2.5 years, 5 years — and the inner bottle's 5-year limit
For dangerous goods transport, three clocks run in parallel (ADR 6.5.4.4 and 4.1.1.15):
- Every 2.5 years: leakproofness test and external inspection. The date must appear on the data plate — if it is missing or older than 2.5 years, the IBC may as a rule no longer be filled with dangerous goods and handed over for carriage (ADR 4.1.2.2).
- Every 5 years: thorough inspection for conformity with the design type, inside and out.
- Max. 5 years' service life of the plastic inner receptacle from its date of manufacture (ADR 4.1.1.15) — read off the inner bottle's date clock, not the IBC date in the UN code. Important: this limit applies to the carriage of dangerous goods; for water or stationary storage, nothing expires here.
When you don't need UN approval
UN approval governs the transport of dangerous goods (ADR, implemented in Germany through the GGVSEB). If you use an IBC in a stationary role — rainwater, service water, process water, counterweight — you don't need a valid UN marking; an expired one is then not a defect but a price argument: a cleaned used 1,000-litre IBC costs €120–180 versus €280–320 new with UN approval (guide price, as of 2026). For the stationary storage of substances hazardous to water, the German AwSV ordinance applies instead of ADR — there it is the manufacturer's release, containment and siting that count, not the UN deadline. Who supplies what is covered in detail in our comparison of IBC manufacturers.
Reconditioned, rebottled — what happens to the UN approval
With cleaning (the old inner bottle stays in), the IBC keeps its UN marking; the 2.5-/5-year intervals and the inner bottle's 5-year limit keep running. Reputable reconditioners work to ISO 9001-certified, BAM-recognised processes and stamp the new leakproofness test onto the data plate.
Rebottled — replacing the inner bottle with a factory-new one built to the original specification — counts as a repair under ADR: the repair shop must test the IBC and apply its own marking in addition to the UN marking (state, inspection body and test date month/year — ADR 6.5.4.5.3). The upside for you: the new bottle restarts the 5-year clock — which is why a rebottled IBC with a food-grade inner bottle (~€230, guide price, as of 2026) is often the most economical option for dangerous goods and sensitive media.
Data plate check before you buy: does the code match the medium (31HA1, Y, density)? Last leakproofness test less than 2.5 years old? Inner bottle's date clock younger than 5 years? Repair marking with test date present, if rebottled? Four glances that prevent a wrong delivery.
Frequently asked questions about IBC UN approval
What does 31HA1 on an IBC mean?
31HA1 is the design type code of the classic composite IBC under ADR 6.5.1.4: 31 = IBC for liquids, H = plastic inner receptacle, A = steel outer packaging (tubular steel cage), 1 = rigid inner receptacle. Practically every 1,000-litre IBC with an inner bottle in a steel cage carries this code.
What does the Y in the UN code mean?
Y means: approved for substances of packing groups II and III. X stands for packing groups I to III — but under ADR 6.5.2.1.1 this applies to solids IBCs only; packing group I liquids are not permitted in IBCs at all. Z stands for packing group III. Which packing group your medium belongs to is listed in ADR Table A — the letter on the IBC must cover it.
How long is an IBC's UN approval valid?
For dangerous goods, three deadlines run in parallel: leakproofness test and external inspection every 2.5 years, thorough inspection every 5 years (ADR 6.5.4.4), and a maximum service life of 5 years for the plastic inner receptacle from its date of manufacture (ADR 4.1.1.15). What counts are the test dates on the data plate and the inner bottle's date clock.
Is a UN-approved IBC automatically suitable for my medium?
No. The UN marking has to match your medium, packing group, density and gasket: packing instruction under ADR Table A, tested density per the approval certificate, chemical compatibility of the HDPE inner bottle, and the right gasket material (EPDM for aqueous media, Viton/FKM for oils and diesel). The code alone is not a blank cheque.
Do I need UN approval for rainwater or stationary storage?
No. UN approval applies to dangerous goods transport under ADR. For stationary water use, an expired UN marking is not a defect and pushes the price down — a cleaned used 1,000-litre IBC costs €120–180 instead of €280–320 new (guide price, as of 2026). For the stationary storage of substances hazardous to water, the German AwSV ordinance applies instead.
Can a rebottled IBC be used for dangerous goods again?
Yes, as a rule: under ADR, swapping the inner bottle counts as a repair. After testing and additional marking by the repair shop (state, inspection body, test date — ADR 6.5.4.5.3), the IBC is fit for dangerous goods again, provided code, density and gasket match the medium. The factory-new inner bottle also restarts the plastic inner receptacle's 5-year clock. What counts are the data plate and the test record — when in doubt, ask a recognised inspection body.
You now know what has to be on the data plate — next you need a supplier who delivers exactly that. Submit your enquiry with a full specification: medium and packing group, volume, UN and/or food-grade inner bottle, filling opening, outlet valve, gasket material, pallet, quantity and delivery frequency. We match it against suitable manufacturers and dealers.
Request a quote with your specificationLast updated: July 2026. Sources: ADR 2025 (chapter 6.5: design types, marking, testing; 4.1.1.15: service life of plastic inner receptacles; 4.1.2.2: test intervals; 6.1.6/4.1.1.21: standard liquids/assimilation list), GGVSEB, AwSV, BAM design type approvals. This is not legal or dangerous goods advice — the data plate, the approval certificate and, when in doubt, a recognised inspection body are authoritative.