The 4G box marked Y25
A warehouse packer is assembling combination packagings for a consignment of UN 1170, ETHANOL SOLUTION, Class 3, PG II. He takes a fibreboard box printed with the mark "4G/Y25/S/24" and "GB/1234", and puts in four 5 L steel cans, each weighing 5.9 kg gross, plus 2 kg of dunnage to stop movement. The finished package weighs 25.6 kg. He closes the box, applies one Class 3 label on the top surface, and writes nothing else on it. When challenged, he says the box is "the right size, the label is on, and Y means it can take anything up to PG II". Separately, twelve of these boxes are to be stacked on a pallet and shrink-wrapped, and the supervisor asks whether the pallet needs its own marks.
1. Is this packaging authorised for the consignment? Decode the UN mark and identify precisely what fails.
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Decode the mark: 4G is a fibreboard box; Y means the design type has been tested for packing groups II and III; 25 is the maximum gross mass in kilograms; S means it is suitable for solids or for inner packagings; 24 is the year of manufacture; GB/1234 identifies the state and the approval holder.
So the packing group is fine - Y covers PG II. The inner packaging is fine - 5 L is within the limit for a Class 3 PG II combination packaging. The failure is the gross mass: four cans at 5.9 kg plus 2 kg of dunnage is 25.6 kg, which exceeds the 25 kg maximum on the mark. The box has not been tested for that load, and the mark is the only evidence the ship has that it will survive the voyage.
Options: remove one can (and the associated dunnage) to bring the package under 25 kg, or use a box whose mark permits a higher gross mass. Nothing else about the package needs to change for this reason.
2. What markings and labels are missing, and where must they go?
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Missing are: the UN number and the proper shipping name, "UN 1170, ETHANOL SOLUTION", marked on the package; and orientation arrows, which are required for combination packagings containing liquids - these boxes contain four liquid cans and will be handled in a container and on a quay.
The Class 3 label is present but is on the top face only. Labels must be on at least one side, clearly visible, unobstructed by other labels or markings, and not folded over an edge; a label on the lid disappears as soon as the boxes are stacked, which is precisely the situation here since twelve are going on a pallet. Put the label on a side face and make sure the marks survive handling.
The supervisor's pallet question is the same issue one level up: if the shrink-wrap hides the marks and labels, the pallet needs to be marked as an overpack. That is the next task.
3. The twelve boxes are shrink-wrapped on a pallet. Is the pallet an overpack, and what must appear on it?
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Yes, in substance and usually in form: a pallet load of packages that is handled as a unit is an overpack where the outer wrapping encloses the packages so that their own marks and labels are no longer visible. If the packages remain visible - marks and labels readable through or around the wrap and on the accessible sides - the pallet needs nothing extra.
If marking is needed, the pallet must show the word OVERPACK (characters at least 12 mm high), together with the UN number and proper shipping name of the goods, and the Class 3 label. The purpose is that anyone receiving, stowing or fighting a fire on that pallet can identify the hazard without breaking it down.
One trap: the overpack mark does not repeat the UN packaging mark - that belongs to the box. And the overpack must not itself compromise the packaging, so the shrink-wrap must not crush the boxes or block any closures that might need venting.