The pattern repeats across the industry: a shipment moves the same lane for years with no issues — until one day a carrier rejects it at the dock. No DG labels. No documentation. The product didn’t change. The scrutiny did.
Where classification actually starts
Every Safety Data Sheet has a Section 14 — Transport Information. If it lists a UN number, proper shipping name, hazard class, and packing group, that product is a regulated dangerous good, full stop. A blank Section 14 doesn’t clear you either — some suppliers simply leave it incomplete.
The fastest check: does your product have a UN number? If yes, it’s regulated across every mode of transport.
One classification, three rulebooks
Dangerous goods are grouped into 9 UN hazard classes globally, but which rulebook applies depends on the leg:
- Ground (US):49 CFR
- Air:IATA DGR
- Ocean:IMDG Code
Cross a border or switch modes, and each leg can bring its own documentation and packaging requirements — even for the same box.
Class 9 catches the most exporters off guard: lithium batteries, dry ice, magnetized material, elevated-temperature substances. Things that don’t “look” hazardous. Hand sanitizer, acetone-based adhesives, and hydrogen peroxide solutions above 8% concentration all qualify too.
A case from our own operations
We handled this exact scenario on a healthcare shipment moving through Guangzhou: temperature-sensitive medical samples packed with dry ice as the coolant. Dry ice is UN 1845, Class 9 — miscellaneous dangerous goods — because it sublimates into CO2 gas, which builds up pressure inside an aircraft hold if the packaging and quantity aren’t controlled.
To the shipper, it was just packaging material keeping the payload cold. To IATA, it was a regulated substance requiring a declared net quantity per package, Class 9 hazard labeling, and Cargo IMC/ICE-Class notification to the carrier. We caught the gap during documentation review — before the shipment reached the airline’s DG acceptance check — and corrected the packing declaration and labeling so it moved on the intended flight instead of getting held at the dock.
That’s the recurring theme: it’s rarely the product a shipper expects to be regulated. It’s the one packed around it.
Where liability sits
This isn’t a screening failure on the airline or carrier’s part — their DG acceptance checks are rigorous by design. Classification is the shipper’s responsibility, and that’s exactly where regulators and carriers place the liability when something is missed. Non-compliance isn’t a flat fine either — PHMSA can assess civil penalties per violation, per package, adjusted annually. A single unlabeled pallet can mean dozens of violations, on top of rejection fees, storage costs, and rebooking.
Before your next shipment leaves the warehouse
Pull the SDS. Check Section 14. If there’s a UN number, hazard class, or packing group listed — get DG documentation sorted before you book, not after a carrier flags it at the dock.
If your team isn’t sure how to read that section, that’s what a DG-specialized forwarder is for.
Have you ever had a shipment rejected for DG paperwork? What was the product, and how long did it sit?