Which hazmat classes have no packing group

Had a shipper ask me for the “PG” on a Class 2 cylinder today; under 49 CFR/IATA/IMDG, packing groups aren’t assigned to Classes 1, 2, 7, or 9 — PGs mainly show up with Classes 3, 4, 5.1, 6.1, and 8 where degree of danger varies. Anyone else still see PGs scribbled on air waybills for UN1978 or UN2915 and have to scrub them for compliance?

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, I still get “PG III” slapped on UN1978 e‑AWBs; I set a TMS validator to strip PG whenever the 49 CFR 172.101 table shows a dash for Class 2/7/9 and auto‑notify the shipper (eCFR :: 49 CFR 172.101 -- Purpose and use of the hazardous materials table.). Small caveat: people mix up PG with IMDG marine pollutant notes for Class 9, which doesn’t change the no‑PG rule. Are you seeing it more from airline counters or your direct shippers?

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