The Pail With No UN Mark
A small formulator has 12 x 20 L pails of UN3264, CORROSIVE LIQUID, ACIDIC, INORGANIC, N.O.S., Class 8, PG II, ready for a 90 km delivery. Eleven pails are open-head plastic drums marked 'UN 1H2/Y/...' and have a manufacturer's closure-torque specification; the twelfth is an identical drum, but its UN marking was removed when a supplier washed it. The formulator also has a 200 L open-head plastic drum marked 'UN 1H2/Z/...' and wants to use it as an overpack for six of the pails to save space. The pails are filled to 19.5 L; the product has a vapour pressure of 1.2 kPa at 20°C. The driver's van has no cargo-securement rails, and the plan is to lay the pails on their sides under a shelf. The shipper's TDG training certificate is six months old.
1. Can the twelfth pail be shipped? Explain the packaging-marking and performance requirements.
Read the worked answer
No. The UN mark is the visible evidence that the packaging has been tested and certified to a performance level. For a PG II liquid, the packaging must carry an X or Y mark; Z is only for PG III. The eleven 1H2/Y pails are acceptable for PG II if the correct closure and gasket are used and the specified torque is applied. The unmarked pail has no evidence of certification. A user cannot simply stencil a UN mark onto an untested pail; if the drum was reconditioned, only an authorized reconditioner can apply the mark.
The shipper must replace the unmarked pail or transfer the contents into a properly marked pail. The shipper should also check that the pails are compatible with the acid, that the closures are tight, and that the packaging is suitable for the intended route. The training certificate being current does not make an uncertified package legal.
2. Evaluate the proposed overpack and the plan to lay the pails on their sides.
Read the worked answer
The 200 L 1H2/Z drum is not suitable as a UN packaging for PG II contents because Z is rated only for PG III. As an overpack, the inner 1H2/Y pails remain the means of containment, but the overpack must meet the overpack rules: it must be marked 'OVERPACK' and, if the inner marks are not visible, marked with the UN number and proper shipping name. It must not reduce the performance of the inner packages. The Z rating is a warning that this drum was not tested for PG II as a packaging, so the shipper should not treat it as a free upgrade.
Laying pails on their sides is poor practice. Even with low vapour pressure, closures can weep or open under vibration. Keep the pails upright, secure them with dunnage or restraints, and do not rely on a shelf to contain them. If the van has no restraint rails, use load bars, pallets, or a contained load area. The shipper should also confirm the vehicle is suitable and that the driver has the shipping document and emergency number.
3. What must the shipper verify before the van leaves?
Read the worked answer
The shipper should verify that every package is a marked UN specification packaging appropriate for Class 8, PG II; that closures are tight to the manufacturer's torque; that the packages are compatible with the acid; that labels and marks are present; that the overpack, if used, is marked correctly; that the load is restrained and upright; and that a compliant shipping document with a 24-hour technical emergency number accompanies the load. The shipper should also confirm that the driver has TDG training or is otherwise authorized, and that the vehicle has placards if the quantity exceeds the placarding threshold. The shipper should record the packaging check and correct the unmarked pail before loading.