UN packaging

UN packaging code decoder

Paste a UN packaging code (e.g. 1A1, 4G, 5H2). The tool decodes kind (drum / box / bag / IBC), material (steel / plastic / fibreboard / paper), category (closed top, open top), the X/Y/Z packing-group mark, and the density limit.

Last updated 2026-05-09. Math runs in your browser, no data leaves your computer.

General guidance only, not legal or professional engineering advice. Verify against the cited primary sources (IMDG, REACH, ChAFTA, RCEP, Customs Tariff Act, supplier SDS, etc.) before committing to a shipment, declaration, or contract. Sourzi assumes no liability for outcomes based on these calculators.

UN packaging codes are stamped on every drum, jerrican, box, bag, and IBC approved for hazardous goods. The code names what the packaging is approved to carry; mismatches between cargo and packaging are a customs and carrier hold trigger.

Common codes

1A1 Closed top, non-removable head steel drum (typical 200 L liquid drum)
1A2 Open top, removable head steel drum
1H1 Closed top plastic (HDPE) drum
1H2 Open top plastic drum
3H1 Closed top plastic jerrican (typical 25 L)
4G Fibreboard box (cardboard carton)
4H2 Solid plastic box
5H4 Plastic film bag
5M2 Multi-wall paper bag, water-resistant
6HA1 IBC, plastic inner with steel outer

Reference tables

Kind codes (first digit)

1Drum
2Wooden barrel
3Jerrican
4Box
5Bag
6Composite packaging
7Pressure receptacle

Material codes (letter)

ASteel
BAluminium
CNatural wood
DPlywood
FReconstituted wood
GFibreboard
HPlastics
LTextile
MMulti-wall paper
NMetal (other than steel/aluminium)
PGlass / ceramic / pottery

UN packaging marks tie cargo to container

UN-rated packaging is the regulator approval that a drum, jerrican, box, bag, or IBC can carry hazardous cargo of a specified Packing Group. The mark is stamped or moulded into the packaging itself; it is never on a label or sticker. The carrier and customs verify by reading the stamp directly. Without the right UN mark, hazmat cargo cannot ship; the carrier offloads at origin or the cargo is held at destination customs.

The full mark is dense. UN 1A1/Y1.4/100/24/USA/M5678 reads: UN preamble; 1A1 = closed-top steel drum; Y = approved for Packing Group II and III; 1.4 = max cargo specific gravity; 100 = hydraulic test pressure 100 kPa; 24 = manufactured 2024; USA = country of approval (or a country code); M5678 = manufacturer reference. Each token is verified against the cargo SDS before loading.

Packing Group is the cargo-side input. Most chemical hazmat falls into Class 3 (flammable liquids), Class 4 (flammable solids), Class 6.1 (toxic), or Class 8 (corrosive). Each class subdivides into Packing Groups: PG I high danger, PG II medium, PG III low. The packaging X/Y/Z must equal or exceed the cargo PG: PG I needs X; PG II needs X or Y; PG III accepts X, Y, or Z.

For chemical liquid cargo at a specific gravity above the drum-marked limit (e.g. sulphuric acid at SG 1.83 in a Y1.4 drum), the packaging fails the carrier check. The buyer side either re-drums into a higher-rated container (X1.9 or Y1.9 typical) or rejects the shipment. Always cross-check the cargo SDS section 9 SG against the drum mark before loading.

Frequently asked

What does a UN packaging code look like?

Format: number + letter(s) + number. Example 1A1: kind code 1 (drum), material A (steel), category 1 (closed top, non-removable head). Example 4G: kind 4 (box), material G (fibreboard). The full form often includes a packing-group letter (X, Y, or Z) plus the year of manufacture and the test pressure.

What do X, Y, and Z mean on the code?

X = approved for Packing Groups I, II, III (most hazardous, plus medium and low). Y = approved for Packing Groups II and III only. Z = approved for Packing Group III only (least hazardous). The marking must match the cargo Packing Group.

How do I read 1A1/Y1.4/100/24/USA/M5678?

1A1 = closed-top steel drum; Y = approved for PG II and III; 1.4 = relative density limit 1.4 (cargo with SG above 1.4 cannot use this drum); 100 = hydraulic test pressure 100 kPa; 24 = manufactured in 2024; USA = country of approval; M5678 = manufacturer mark. The full string is the legal stamp on the drum.

When is the year of manufacture mark important?

Per UN Model Regulations 4.1.1.15, PLASTIC drums, jerricans, and rigid-plastic IBCs (and composite IBCs with plastic inner) have a 5-year limit from date of manufacture. STEEL and other metal packagings are NOT subject to a strict 5-year rule; they are inspection-based reuse per the carrier and regulator. A plastic drum manufactured in 2020 cannot ship liquid hazmat in 2026 even if it looks pristine. Customs and carrier inspectors check the year-of-manufacture mark.

Related tools