Column 9: Quantity Limitations
Column 9 tells you how much of a material you're allowed to ship by air, split into two sub-columns: passenger aircraft/rail, and cargo aircraft only.
Column 9 has two parts: "Passenger Aircraft/Rail" and "Cargo Aircraft Only." Each shows the maximum quantity per package allowed under that mode — and the two numbers are often very different. A material that's tightly limited or forbidden on a passenger flight may have a much higher limit, or no limit at all, when shipped on a cargo-only aircraft.
What am I looking at?
Two sub-columns, each showing a maximum net quantity per package (in kg or L depending on the material's physical state), or the word "Forbidden" if that mode isn't allowed at all for the material. The left sub-column applies to aircraft carrying passengers and to rail transport; the right applies only to aircraft carrying cargo with no passengers aboard.
What does it mean?
Aviation safety regulators treat passenger flights more conservatively than cargo-only flights, since a hazmat incident on a passenger aircraft puts far more people at risk. That's why the same material frequently gets a smaller quantity allowance — or an outright "Forbidden" — in the passenger/rail sub-column, while the cargo-only sub-column allows a larger quantity or has no quantity limit at all. This column only governs air and rail; highway and vessel quantity limits are handled elsewhere in the regulations.
A practical example
Many corrosive materials are forbidden entirely on passenger aircraft but permitted in limited quantities on cargo-only aircraft. If you're arranging air freight and your carrier or forwarder is routing through passenger aircraft rather than a dedicated cargo carrier, a shipment that would be perfectly fine on a cargo-only flight can become non-shippable — which is exactly why checking Column 9 before booking air transport matters, not after.
Common mistake
Assuming "quantity limitation" means the same thing across all modes of transport. Column 9 applies specifically to air and rail — it says nothing about how much you can ship by highway or vessel, which are governed by different sections of the regulations (including gross vs. net quantity distinctions that don't apply the same way here). Applying an air quantity limit to a truck shipment, or vice versa, is a common and consequential error.
What should I check next?
If you're shipping by air, confirm which sub-column applies based on whether your carrier uses passenger or cargo-only aircraft, then check the actual quantity in your package against that limit. If you're shipping by highway or vessel instead, Column 9 doesn't govern your shipment at all — look at packaging references (Column 8) and vessel stowage (Column 10) instead.