A rating — I (high danger), II (medium) or III (low) — that sets how robustly a dangerous substance must be packaged. Not every entry has one: many Class 9 lithium batteries, for instance, are assigned no packing group but follow their own detailed packing instructions instead. Where a PG does apply, it determines the packaging performance standard the container must meet.
Full guideDangerous goods documentation: what has to match, and why one line holds the shipment →