A hazmat shipping paper reads: "UN1824, Sodium hydroxide solution, 8, PG II, 4,500 lbs." What does the "PG II" portion represent?

49 CFR 172.202(a)(4); AAMVA CDL Manual, Section 9.3.5 (nhcdm.pdf p. 9-6/9-7)

Packing group tells responders and carriers how dangerous a specific shipment is within its hazard class — PG I, II, and III each carry different packaging strength requirements and, as the ELDT Penalty Reference shows, different civil-penalty amounts when shipping papers are missing or wrong, so misreading it has real financial and safety stakes.