If you have ever looked closely at the cage of an IBC tote, you have seen the markings: a hollow “UN” logo followed by a string of characters that look like a serial number ran into an alphabet soup. They are not random. Each character is regulatory. Here is what they mean.
The code, broken down
A typical marking on a 275-gallon caged HDPE IBC reads something like:
⊕ 31HA1/Y/0824/USA/A4444 1500/3000
Working left to right:
- ⊕ — the United Nations packaging symbol. Means “this packaging is certified for hazardous goods transport.”
- 31 — the IBC type code. “31” means a rigid IBC intended for liquids.
- H — the material code. “H” is rigid plastic. “A” is steel, “B” is aluminum.
- A — the construction style. “A” means rigid plastic with structural equipment (the cage). “B” means standalone rigid plastic. “Z” means composite.
- 1 — the design category. “1” is for liquids; “2” is for solids.
- Y — the packing group. “Y” covers packing groups II and III. “X” would cover I, II, and III.
- 08/24 — the manufacture date. Month/year. This tote is from August 2024.
- USA — country of certification.
- A4444 — the manufacturer’s code.
- 1500 — maximum gross mass in kilograms.
- 3000 — internal pressure test value in kPa, divided by 10 by some markings.
What survives reconditioning
The UN marking survives reconditioning unchanged. The original certification is preserved. What changes is that a reconditioner adds their own stamp next to the original, indicating who reconditioned it and when. Our stamp is a small “IBC-R / 06-26 / WI-04” under the original marking, meaning IBC Reconditioned, June 2026, our facility code.
What this means for shipping
For hazardous-materials shipping, the original UN certification is what the carrier checks. A reconditioned tote with intact markings is treated identically to a new tote with the same certification. The reconditioner stamp matters for chain of custody and re-test records — not for the haz-mat classification itself.
The retest interval
IBCs intended for haz-mat transport require periodic inspection and retest. The standard interval is 2.5 years for external visual and leak-tightness; 5 years for full pressure retest. Reconditioning resets these intervals because every reconditioned tote passes a leak test as part of our 14-step process. The date on our stamp is the new clock-start.