Dangerous goods are items that can endanger health, safety or property in flight, grouped into nine hazard classes from explosives (Class 1) to miscellaneous dangerous goods such as lithium batteries and dry ice (Class 9). They can only fly when a trained shipper has correctly classified, packed, marked, labeled and declared them under the IATA Dangerous Goods Regulations.
Key takeaways
- There are nine hazard classes, and many everyday products fall into them, from perfume to paint to batteries.
- The shipper is legally responsible for classifying, packing, marking, labeling and declaring dangerous goods, usually with a Shipper's Declaration for Dangerous Goods.
- Every item is either forbidden, allowed on cargo aircraft only, or allowed on passenger and cargo aircraft within limits.
- Staff who prepare DG shipments need training: IATA DGR certificates are valid for 24 months, and US hazmat rules require recurrent training at least every three years.
- The IATA DGR is updated every year, with each edition effective from 1 January.
What counts as dangerous goods in air freight?
Any article or substance that can pose a risk to health, safety, property or the environment when carried by air.
That covers far more than industrial chemicals. Perfume, nail polish, aerosols, paints, adhesives, batteries, magnets, dry ice, some medical samples and many machine parts containing fuel or oil are dangerous goods. The international rules come from ICAO's Technical Instructions for the Safe Transport of Dangerous Goods by Air and are published for operational use in the IATA Dangerous Goods Regulations (DGR), which most airlines require shippers to follow. In the United States, the Hazardous Materials Regulations in 49 CFR also apply, and the FAA enforces them for air shipments.
What are the nine hazard classes?
The nine classes group dangerous goods by their main hazard, from explosives to miscellaneous items such as lithium batteries.
| Class | Hazard | Everyday examples |
|---|---|---|
| 1 | Explosives | Fireworks, ammunition, airbag inflators |
| 2 | Gases (flammable, non-flammable, toxic) | Aerosols, gas cylinders, fire extinguishers |
| 3 | Flammable liquids | Perfume, paint, alcohol-based products, fuel |
| 4 | Flammable solids and substances that react | Matches, some metal powders |
| 5 | Oxidizers and organic peroxides | Some pool chemicals, hydrogen peroxide solutions |
| 6 | Toxic and infectious substances | Pesticides, some diagnostic specimens |
| 7 | Radioactive material | Medical isotopes, some gauges |
| 8 | Corrosives | Wet-cell batteries, acids, some cleaning products |
| 9 | Miscellaneous dangerous goods | Lithium batteries, dry ice, magnetized material, vehicles |
Each class is split into divisions or packing groups. Packing group I is high danger, II medium and III low, and the packing group sets packaging strength and quantity limits. Lithium batteries have their own detailed rules, covered in our guide to shipping lithium batteries by air (UN3480 and UN3481).
What are the shipper's responsibilities for dangerous goods?
The shipper must classify, pack, mark, label and document the goods, and sign a Shipper's Declaration for Dangerous Goods where one is required. Our guide shows how to fill in the Shipper's Declaration box by box.
Airlines and forwarders check shipments at acceptance, but the legal duty sits with the person offering the goods for transport. In practice that means:
- Classify: identify the substance or article, its UN number, proper shipping name, class or division and packing group, usually starting from section 14 of the safety data sheet.
- Check restrictions: confirm whether it is forbidden, cargo aircraft only, or allowed on passenger aircraft, and check state and operator variations for every airline and country on the route.
- Pack: use the packing instruction in the DGR list, with UN specification packaging where required and within the quantity limit per package.
- Mark: apply the UN number, proper shipping name, shipper and consignee names and addresses, and net quantity where required.
- Label: apply the hazard label for the class and any handling labels, such as Cargo Aircraft Only.
- Document: complete and sign the Shipper's Declaration for Dangerous Goods (by a trained person) and make sure the air waybill describes the goods correctly.
The declaration lists each item's UN number, proper shipping name, class, packing group, quantity, packing instruction and any authorizations, and confirms the shipment complies with the regulations. Errors on it are among the most common reasons for refused cargo.
Who needs dangerous goods training, and how often?
Anyone who classifies, packs, marks, labels or documents dangerous goods for air transport must be trained for that function, with recurrent training every 24 months under the IATA DGR.
The DGR sets training requirements in subsection 1.5 and now follows a competency-based training and assessment (CBTA) approach: the employer must make sure staff are trained and assessed as competent for the specific tasks they perform. IATA's own course for people preparing DG consignments states that its certificate is valid for 24 months, and that anyone whose certificate is more than two years old must retake the initial course.
In the United States, 49 CFR 172.704 requires general awareness, function-specific, safety and security awareness training for every hazmat employee, with recurrent training at least once every three years. New employees can work under direct supervision for up to 90 days while they complete training. Because air shipments must also meet the DGR, many US shippers follow the 24-month cycle. Shippers of small lithium batteries under Section II of the battery packing instructions are a partial exception: IATA requires documented "adequate instruction" rather than full DGR training.
Forbidden, cargo aircraft only or passenger aircraft: what is the difference?
Every dangerous good falls into one of three categories, and the DGR list entry for its UN number tells you which.
| Category | What it means | Examples |
|---|---|---|
| Forbidden | Cannot fly under any circumstances, or only under a government exemption | Substances that may explode or react dangerously in normal transport conditions; damaged or recalled lithium batteries |
| Cargo aircraft only (CAO) | Allowed on freighters only, with a Cargo Aircraft Only label and usually higher per-package limits | Lithium-ion batteries shipped alone (UN3480); larger quantities of many flammable liquids |
| Passenger and cargo aircraft | Allowed in the hold of passenger aircraft within lower per-package limits | Batteries contained in equipment, small quantities of perfume, dry ice within limits |
The difference matters for routing and cost. A CAO shipment needs freighter capacity on the lane, which may mean a different gateway or a longer transit than belly cargo on a passenger flight. Airlines can also be stricter than the DGR through operator variations, and some do not accept certain classes at all.
What are limited and excepted quantities?
They are relief provisions that let small amounts of some dangerous goods move with simpler packaging, though they remain regulated.
| Provision | How it works | Mark |
|---|---|---|
| Limited quantity | Small inner packagings inside strong outer packaging that need not be UN specification; uses the "Y" packing instructions, with a gross mass cap of 30 kg per package | Limited quantity mark with a "Y" |
| Excepted quantity | Very small amounts (codes E1 to E5 in the DGR list), such as laboratory samples, in tested triple packaging | Excepted quantity mark |
Not every substance qualifies, and the per-package totals are strict, so check the DGR entry for your UN number. Limited quantity shipments still need a Shipper's Declaration; excepted quantity shipments do not, but the air waybill must show the number of packages and the words "Dangerous Goods in Excepted Quantities."
How do you ship dangerous goods without delays?
Classify early, choose an airline that accepts your class on your route, and give the forwarder complete documents before booking.
- Send the safety data sheet with your quote request.
- Ask whether the airline on your lane accepts that class, and on which aircraft type.
- Allow extra time: DG acceptance checks happen before loading, and errors mean the cargo stays behind.
- Keep training current. The DGR changes every year, and certificates must be renewed.
- Never send undeclared dangerous goods. The FAA can issue civil penalties for hazmat violations, and hidden batteries, aerosols and perfume in mixed consignments are a recurring cause of incidents.
If you do not have trained staff in-house, a forwarder or 3PL with DG expertise can prepare the paperwork and packaging. Our checklist for choosing a dangerous goods forwarder or 3PL covers what to ask. For general cargo with occasional DG items, see JumboGeneral, or tell us about your cargo when you request a quote and we will confirm what is needed for your lane.
Frequently asked questions
Is perfume dangerous goods?
Usually yes. Most perfumes and colognes contain alcohol and are classed as Class 3 flammable liquids, although small quantities may qualify for limited or excepted quantity provisions.
Who can sign a Shipper's Declaration for Dangerous Goods?
Only a person trained in dangerous goods to the required standard, signing on behalf of the shipper. The forwarder or airline cannot take that legal responsibility from the shipper.
How often is dangerous goods training required?
Under the IATA DGR, recurrent training is due within 24 months of the previous training, which is why IATA certificates are valid for 24 months. US hazmat rules in 49 CFR 172.704 require recurrent training at least once every three years, so many US shippers follow the stricter 24-month cycle for air.
Is dry ice dangerous goods?
Yes. Dry ice (UN1845) is Class 9 because it releases carbon dioxide gas, and the net quantity per package must be marked and declared to the airline.
What is the difference between ICAO TI and the IATA DGR?
The ICAO Technical Instructions are the legal basis; the IATA DGR incorporates them plus airline requirements in an operational manual that most of the industry works from.
