Reading the UN marking on a tote

The marking, part by part

Every IBC built to a UN standard carries the same set of marks in the same order, set out in 49 CFR 178.703(a). On a caged tote they are on a plate fixed to the front of the cage. The drawing below sets them out in that order. The weights differ from design to design, so they are left blank; the order doesn't change.

What each part tells you

The UN symbol. The letters "un" in a circle: the IBC was built and tested to a UN design type.

The code, 31HA1. 31 means a rigid IBC for liquids. H is the inner material, plastic. A is the outer, steel. The final 1 marks a rigid plastic inner receptacle; a 31HA2 has a flexible one (49 CFR 178.707). For a steel IBC the code is 31A.

The packing group letter. X means the design passed the tests for Packing Groups I, II and III (for solids), Y for II and III, Z for III only. Caged totes are almost always Y. The number after it, on most totes, is the highest specific gravity the design was tested at: Y1.9 or Y1.6. See specific gravity ratings.

Month and year of manufacture. The start of the 2.5-year retest clock.

Country. The state that authorized the mark: USA, or the code of the country where the design was approved.

Maker. The name or registered symbol of the manufacturer.

Stacking test load, kg. The load the design carried in the stacking test. A tote not designed for stacking shows 0. Since 2011 the plate also carries a stacking symbol, at least 100 mm square, showing whether the IBC may be stacked.

Maximum permissible gross mass, kg. The tote plus its contents may not weigh more than this.

The second block: capacity, tare and dates

Next to those marks, composite and rigid plastic IBCs must show the rated capacity in litres of water at 20 °C, the tare mass in kg, the gauge test pressure in kPa, and the month and year of the last leakproofness test and the last inspection (49 CFR 178.703(b)(1)). Metal IBCs carry the same on a corrosion-resistant plate, plus the body material and its minimum thickness, a maximum loading and discharge pressure where it applies, and the maker's serial number.

The bottle of a composite tote is marked too, with its own design code, maker, country and date of manufacture. That date may differ from the cage plate's (178.703(b)(6)), which is how a rebottled tote shows itself.

What to check before you fill

Read the code and letter against your product's SDS: section 14 gives the packing group, section 9 the specific gravity. Check the latest test date is less than 2.5 years old, since a tote whose test is due may not be filled for transport (49 CFR 173.35(a)). Work out the full weight, product plus tare, and check it is under the maximum gross mass. On a new tote all of this should read cleanly, with one recent date.

A full plate, read line by line

Take a plate that reads, in order: the UN symbol, 31HA1/Y, a month and year of manufacture, USA, a maker's mark, a stacking test load in kilograms, and a maximum permissible gross mass in kilograms. The first line tells you it is a composite IBC with a plastic bottle in a steel cage, rated for Packing Groups II and III. The date starts the retest clock. USA is the country that authorised the marking. The stacking and gross mass figures tell you what may stand on it and how heavy it may be when full.

Below or beside it, on composite and plastic designs, you should find the rated capacity in litres at 20 °C and the tare in kilograms (49 CFR 178.703(b)). The bottle carries its own moulded mark with its own date, because a bottle can be replaced while the cage stays. Compare the two dates: on a new tote they should match or be close.

When the plate is missing or unreadable

A tote with a lost, corroded or painted-over plate can't be shown to meet the standard, and shouldn't be used for regulated product until it is identified. Don't guess from the look of the tote. Contact the maker with any serial number that remains; if the tote can't be traced, take it out of hazmat service.

Short answers

What does the Y mean in 31HA1/Y?

The design passed the tests for Packing Group II and III. It may not carry Packing Group I, and no IBC may carry a Packing Group I liquid in any case.

What is the difference between 31HA1 and 31H1?

31HA1 is a composite tote: a plastic bottle in a steel cage. 31H1 is a rigid plastic IBC with structural equipment that carries the stacking load, with no separate bottle.

Where is the date of manufacture on a tote?

On the plate on the front of the cage, as month and year, after the packing group letter. The bottle carries its own date as well.

What does USA on a tote plate mean?

It is the state that authorised the marking, here the US. A tote made elsewhere shows that country’s letters.

What does the X, Y or Z letter mean?

It is the packing group the design was tested for: X covers Packing Groups I, II and III, Y covers II and III, and Z covers III only. No IBC may carry a Packing Group I liquid.

Where is the plate on a caged tote?

Usually on the cage’s front panel, near the valve. The bottle has its own moulded marks too.

What do the stacking symbol and kilogram figure show?

Since 2011 new IBCs carry a symbol showing whether they may be stacked, and the maximum load in kilograms permitted on top. A crossed-out symbol means do not stack.

Is the date of manufacture the same as an expiry date?

No. It starts the retest and inspection cycle. A tote does not expire, but it must pass its tests to stay in hazmat service.

What does 1 or 2 after the letters mean?

For composite IBCs, 1 marks a rigid inner bottle and 2 a flexible one. Caged totes for liquids are almost always 1.

Can I re-mark a tote myself?

No. Marks are applied by the manufacturer, or by a repairer or retester for the marks their work requires. Altering them is not allowed.

Why are there two dates on some totes?

One is the manufacture date of the IBC; others record later tests, inspections or a repair. The bottle may also carry its own moulding date.