"Dangerous goods" sounds like explosives and chemicals. In practice, the shipments that cause most problems are ordinary products: perfume, nail polish, hand sanitiser, aerosols, paint, and anything with a lithium battery. Shipped undeclared, any of them can be refused, returned or held — and in the worst case, cause an incident in flight.
Air transport of dangerous goods is governed by the IATA Dangerous Goods Regulations, built on UN recommendations. Every regulated substance is assigned to one of nine hazard classes and given a four-digit UN number.
The nine hazard classes
| Class | Hazard | Everyday examples |
|---|---|---|
| 1 | Explosives | Fireworks, flares, ammunition |
| 2 | Gases | Aerosols, gas cylinders, fire extinguishers |
| 3 | Flammable liquids | Perfume, nail polish, paint, adhesives, alcohol-based sanitiser |
| 4 | Flammable solids | Matches, some metal powders |
| 5 | Oxidisers and organic peroxides | Pool chemicals, some hair bleaches |
| 6 | Toxic and infectious substances | Pesticides, medical specimens |
| 7 | Radioactive material | Some medical and industrial sources |
| 8 | Corrosives | Wet-cell batteries, some cleaning products |
| 9 | Miscellaneous | Lithium batteries, dry ice, magnetised material |
Lithium batteries: the most common problem
Lithium batteries are the dangerous good shippers meet most often, because they are in so many products. Damaged or defective cells can overheat and ignite, so their carriage by air is tightly controlled. Requirements depend on three things:
- The chemistry — lithium-ion (rechargeable) or lithium metal (usually non-rechargeable).
- How it is packed — on its own, packed with equipment, or installed inside equipment. Each has its own UN number.
- The size — measured in watt-hours for lithium-ion and lithium content for lithium metal, which decides how strictly it is regulated.
| UN number | Description |
|---|---|
| UN3480 | Lithium-ion batteries, shipped on their own |
| UN3481 | Lithium-ion batteries packed with, or contained in, equipment |
| UN3090 | Lithium metal batteries, shipped on their own |
| UN3091 | Lithium metal batteries packed with, or contained in, equipment |
The shipper's responsibility
Responsibility for classifying, packing, marking and declaring dangerous goods rests with the shipper. That includes using UN-specification packaging where required, applying the correct hazard labels and handling marks, and completing a Shipper's Declaration for Dangerous Goods. Staff who prepare dangerous goods shipments must be trained to do it.
Some goods are forbidden on aircraft entirely. Others are allowed only on cargo aircraft, or only in limited quantities. A few are permitted in small consumer quantities under simplified rules.
What to do before shipping
- Check the safety data sheet for any chemical product. Section 14 gives its transport classification and UN number.
- List anything with a battery, and note its type and rating.
- Tell your forwarder before booking. Not every service or route accepts every class.
- Never under-declare. Mis-describing dangerous goods to avoid restrictions is an offence in most countries, and the safety risk is real.