Dangerous Goods are articles or substances which are capable of posing a significant risk to health, safety, property or environment.

Transport of dangerous goods is strictly regulated by IATA Dangerous Goods Regulations.

There are nine UN hazard classes of dangerous goods:
Class 1 - Explosives
Class 2 - Gases
Class 3 - Flammable liquids
Class 4 - Flammable solids
Class 5 - Oxidizing substances and Organic Peroxides
Class 6 - Toxic and infectious substances
Class 7 - Radioactive materials
Class 8 - Corrosives
Class 9 - Miscellaneous dangerous goods

Each package should have a proper label attached. The kind of label depends on the type of hazard.

Dangerous Goods can be divided into the following groups:

1. Forbidden Dangerous Goods: all substances which may:
- explode
- dangerously react
- produce a flame
- produce dangerous evolution of heat
- produce dangerous emission of toxic
but also:
- corrosive
- flammable gases or vapours

2. Hidden Dangerous Goods:
- cars and car parts
- diving equipment
- dental materials
- electrical equipment
- chemicals
- household goods

Before the shipment of hidden dangerous goods, the sender should confirm in writing that there isn't any dangerous element in the package.

3. Dangerous Goods in Air Mail
It is forbidden to carry dangerous goods in air mail with the exception of:
- infectious substances
- patient specimens
- radioactive material, provided that the activity does not exceed 1/10 of that permitted in Table 10.5.A DGR

4. Dangerous Goods in Operator's Property.
Those are such goods that in other circumstances would be forbidden on aircraft, but their presence is required according to security or operating regulations.
- aircraft equipment
- aircraft spares
- carbon dioxide solid (dry ice) used in food and beverage service
- consumer goods, like aerosols, alcoholic beverages, perfumes, colognes etc.

5. Dangerous Goods Carried by Passengers or Crew
Dangerous goods must not be carried by passengers or crew, exceptions shown in table 2.3.A DGR

6. Dangerous Goods Permitted as Air Cargo
Are dangerous goods, which the transport of is not forbidden on an aircraft.

All personnel handling or transporting dangerous goods in any way are obliged to be trained in dangerous goods regulations applicable to their duties.
This rule applies to the following personnel:
- all shippers and agents offering the consignments
- those who are packing the goods
- those who accept the goods for the shipment
- those responsible for handling, storage and loading of the goods
- all personnel engaged in passenger and baggage check-in
- aircrew