Packaging, IBCs, large packagings, tank-wagons, tank-containers and portable tanks
Two layers of rules
Part 4 governs use (which instruction applies, how much, what may be mixed), Part 6 governs construction and testing. A packaging is only acceptable if both layers line up: the entry in Table A gives the instruction (P, IBC, LP, or tank instruction), and Part 6 sets the design, test and marking regime.
Packagings, IBCs and large packagings
UN packaging codes carry X (PG I, II and III), Y (II and III) or Z (III only), so a Z-marked drum may never carry PG I goods. Combination packagings must follow the instruction's inner/outer limits, and the UN mark records the year of manufacture, the country and the test pressure for pressure receptacles. Empty uncleaned packagings remain subject to the rules unless residues are removed.
Tank-wagons, tank-containers and portable tanks
Tank provisions sit in Chapters 4.3, 6.7 (portable tanks) and 6.8 (tank-wagons, demountable tanks, battery-wagons, tank-containers). The RID tank code attached to each entry defines the tank type and the minimum test pressure, and the degree of filling is limited - for liquids generally so that the tank is not liquid-full at 50 °C, calculated by the formula in 4.3.2.2. Every tank carries a tank plate with capacity, test pressure, dates and the operator's name; it may not be used if the next inspection is overdue.
Worked example
A consignor orders a tank-wagon for a Class 8 liquid. Table A gives tank code L4BH and packing group II. The wagon offered bears a tank plate whose inspection date has expired and whose code is L10BH. Test pressure higher - but the code is not the one required and the inspection is out of date: reject the wagon on both counts.
Traps
Reading only the packing instruction and not the special packing provisions; accepting a Y-marked packaging for PG I; forgetting the filling limit for heated liquids; overlooking that portable tanks have their own inspection regime.