UN packaging code decoder

How to read a UN packaging mark

Every UN mark on a drum, jerrican or box follows the same order, set by chapter 6.1 of the UN Model Regulations. Read it left to right and each part answers one question.

1. The UN symbol or the letters UN. The design passed the UN tests for dangerous goods packaging.
2. The packaging code, such as 3H1: the type of packaging, its material and, on drums and jerricans, whether the head comes off.
3. The performance level: X, Y or Z, the packing groups it may carry. For liquids a relative density follows, left off when it is 1.2 or below. For solids it is the maximum gross mass in kilograms.
4. The test pressure, or S. For liquids, the hydraulic test pressure in kPa. For solids and inner packagings, the letter S.
5. The year of manufacture, as two digits. Plastic drums and jerricans also show the month, usually on a clock symbol.
6. The approving country, as its international vehicle sign: D for Germany, F for France, USA for the United States.
7. The manufacturer or approval number, in the form the approving authority sets.

The packaging code: type, material, head

For drums, jerricans, boxes and bags the code is a digit, a letter and usually a second digit. The first digit gives the type, the letter the material, and the last digit, on drums and jerricans, whether the head is fixed. Composite packagings use two letters, inner material first. IBCs use two-digit codes such as 31H1 under their own section of the regulations.

Codes you will meet most often

One page per code: UN 3H1 · UN 3H2 · UN 3A1 · UN 3A2 · UN 3B1 · UN 1A1 · UN 1A2 · UN 1H1 · UN 1H2 · UN 4G · UN 31HA1 · UN 31H1

Worked examples

UN 3H1/Y1.9/150/26/D/BAM 12345

Made to this code in our range: HDPE jerrycans.

UN 3A1/X1.3/250/26/GB/2345

Made to this code in our range: Steel jerry cans.

UN 1A1/X1.6/250/24/USA/M4321

Made to this code in our range: Tight-head round metal buckets.

UN 1A2/Y30/S/26/GB/2468

Made to this code in our range: Metal pails with flower lid or lever ring.

UN 31HA1/Y/02 26/D/BAM 1234/2160/1200

We do not make IBCs. Our IBC spill pallets hold one, and the spill pallet calculator sizes the sump.

What the mark does not tell you

Whether it suits your contents. Type your UN number under a decoded mark and the decoder checks the packing instruction, the size and the mark’s letter against it. Starting from a UN number instead, the UN number packaging finder lists every container it may use. The mark shows the packing groups and density the design was tested for, not every substance it can hold. A plastic container also has to be compatible with the actual chemical; our chemical compatibility guide covers how to check.

How long it can be used. Under ADR, plastic drums and jerricans carrying dangerous goods may be used for five years from the month and year of manufacture, so read the date before you fill. Our guide to cleaning and reusing jerry cans sets out the rule.

When an IBC is due for testing. The mark gives the month and year of manufacture; the plate beside it gives the last test and inspection. Our IBC inspection date checker turns them into the next due dates.

Which plant made it. Approval belongs to a design made at a particular plant. Ask the supplier for the certificate that names the plant your containers come from; the mark alone will not tell you. Our UN packaging codes guide explains why.

Put this tool on your site

Safety advisers, trainers and trade bodies can embed it free. Paste the code into any web page. The tool updates when we update the rules, and the credit line links back here. Building software instead? The same answer comes as JSON from our free API.

Common questions

What does 3H1 mean on a jerry can?

3H1 is a closed-head plastic jerrican: 3 means jerrican, H means plastic and 1 means the head is not removable, so it fills and empties through a small neck. It is the code on UN-approved plastic jerricans for liquids.

What is the difference between 1A1 and 1A2?

Both are steel drums. 1A1 has a fixed head with openings no wider than 7 cm and is the usual choice for liquids. 1A2 has a removable lid, or any opening wider than 7 cm. It carries solids and liquids of packing groups II and III, and in packing group I only viscous liquids.

What does Y1.9 mean in a UN code?

Y means the design is approved for packing groups II and III, medium and low danger. 1.9 is the highest relative density of liquid it was tested with, so it can carry liquids up to 1.9 times the density of water. When no figure appears, the limit is 1.2.

What does 150 mean in a UN packaging mark?

On a packaging for liquids, the number after the performance level is the hydraulic test pressure in kPa that the design passed, here 150 kPa. Packagings for solids show the letter S in that place instead.

References

The standards and regulations this page relies on, at their issuing body. Where a market rule is named here, check the current revision before you specify against it.

• UN Model Regulations on the Transport of Dangerous Goods (Rev. 24)
• UNECE — the ADR agreement, whose Chapter 6.1 sets packaging codes and marking
• ADR — European agreement on international carriage of dangerous goods by road