Dangerous Goods are articles or substances which are capable of posing a hazard to health, safety, property, or the environment when transported by air. 

Unknown to some, many household items, consumer products and industrial supplies (e.g. lithium batteries, aerosol cans, and compressed gas cylinders) are classified as dangerous goods. When such items are transported by air, they can become a hazard if not declared, packed and handled properly. For safety reasons, it is therefore important to observe the regulations and requirements on the carriage of dangerous goods by air. 

Some common examples of dangerous goods can be found here

To ensure the safe transport of dangerous goods by air, shippers, freight forwarders and air operators must comply with the following regulations and requirements in place: 

Responsibilities of Shippers and Freight Forwarders

Responsibilities of Air Operators

Training Requirements

Dangerous goods are classified according to the ICAO Technical Instructions for the Safe Transport of Dangerous Goods by Air. The manual containing the full list of dangerous goods may be acquired here.