What counts as dangerous goods
In air transport, dangerous goods are articles or substances that could pose a risk to safety, health, property or the aircraft if they are not handled correctly. The category is broader than many sellers expect. It includes obvious items such as explosives and compressed gases, but also everyday products such as lithium batteries, aerosols, perfumes, nail polish, paints, cleaning products and some magnets.
The reason is the environment. An aircraft flies at altitude, with pressure and temperature changes, vibration and limited ability to respond to a fire. A leak, short circuit or overheating battery that would be a nuisance on the ground can be far more serious in the air. The international rules for air transport are set by the industry and aviation authorities, and carriers apply them with their own additional restrictions. Because the rules are detailed and updated regularly, this article gives the general picture only; the carrier and the current regulations decide what applies to a specific shipment.
Batteries
Lithium batteries are the most common source of problems in e-commerce parcels. There are two main chemistries: lithium-ion (rechargeable) and lithium metal (often non-rechargeable). The rules differ for each, and also depend on whether the batteries are:
- shipped on their own;
- packed with equipment, meaning included in the same box as the device they power; or
- contained in equipment, meaning installed inside the device.
Size matters too. Limits are usually expressed in watt-hours for lithium-ion batteries and in grams of lithium content for lithium metal. Smaller batteries often qualify for lighter requirements, while larger ones are subject to full dangerous goods procedures. Many carriers also have rules such as a limit on how many batteries or devices can be in one package, and some do not accept certain categories on certain services at all. Batteries that are damaged, defective or recalled are generally prohibited from standard air carriage.
Why the strict treatment? Lithium cells can undergo thermal runaway, in which a cell overheats and can set off neighbouring cells. Fires in this class of cargo are hard to extinguish. This is why packaging, labelling and quantity limits are tightly controlled.
Liquids and aerosols
Liquids are not automatically dangerous goods. Water-based, non-flammable products such as many drinks or shampoos can usually be shipped normally, although leaks are still a packing risk. The concern is with liquids that are flammable, corrosive, toxic or otherwise hazardous, and with pressurized containers.
- Aerosols such as deodorants, hair sprays and paints are pressurized, and many are flammable. Air rules usually limit the size of each container and the total quantity per package.
- Perfumes and nail polish often contain flammable solvents.
- Alcohol at certain strengths is flammable.
- Cleaning chemicals may be corrosive or toxic.
- Liquids in general may be affected by pressure changes, so containers should be designed to avoid leaks.
If a product has a safety data sheet, that document is often the starting point for classification, because it lists flammability, corrosivity and other properties. Do not guess. Ask the manufacturer for the transport classification.
What shippers must declare
The shipper is responsible for correctly identifying, classifying, packing, marking and documenting dangerous goods. In practice, the process often involves:
- Classification. Determining whether the item is regulated and, if so, which class and identification number apply.
- Packaging. Using packaging that meets the specifications for that class and quantity, and which has been tested for the purpose.
- Marking and labelling. Applying hazard labels and any required handling marks to the outside of the package.
- Documentation. For fully regulated goods, a shipper’s declaration completed by someone with the proper training. Some lower-risk shipments instead use a simple statement or marking.
- Notification. Telling the carrier or forwarder in advance, because many do not accept dangerous goods without prior approval.
Mistakes in this area are serious. Undeclared or wrongly declared goods can be refused, held, returned or destroyed. In some countries they can lead to fines or other legal consequences, and in the worst case they can endanger lives. Never leave out information about a battery or liquid to avoid extra cost or a refusal.
Differences between passenger and cargo aircraft
Some dangerous goods are allowed on freighters but not on passenger aircraft, or are subject to smaller quantity limits in the latter. Items marked “cargo aircraft only” may not travel in the hold of a passenger flight. This is one reason the choice between belly cargo and freighters matters for restricted products. Express networks often route such goods on freighter-only services.
Reducing problems with ordinary products
- Check your catalogue. Identify any products with batteries, aerosols, flammable liquids, magnets or chemicals.
- Get the data. Record watt-hours, lithium content, volumes and safety data sheet details for each product.
- Ask the carrier early. Confirm whether the service accepts the product, in what quantity and with what packaging.
- Train staff. People who pack and sign for dangerous goods usually need specific training; this is a requirement, not a nicety.
- Use compliant packaging. Protect devices from accidental activation and short circuits, and keep batteries from moving inside the box.
- Consider other modes. If a product is difficult by air, a ground or sea service may suit better, depending on the destination.
The wider topic of restricted and prohibited items in international shipping and the general importance of regulatory compliance both overlap with this subject. When in doubt about a product, stop and ask before it is packed, since correcting a mistake after handover is far harder.