Dangerous goods (abbreviated as DG) are generally items or substances that can risk health, safety, property or the environment when being transported. Hazardous goods or materials (abbreviated as HAZMAT) are substances, solids, liquids or gases that can harm people, animals, property or the environment, and therefore have to adhere to chemical regulations.

Hazardous goods include materials that are radioactive, flammable, explosive, corrosive, oxidizing, toxic, pathogenic or allergenic. Furthermore, physical conditions such as compressed gases and liquids or hot materials can be classified as hazardous during certain circumstances, for example, if a gas reaches a temperature that could make it hazardous or vulnerable to become dangerous.