Infectious substances
Infectious substances are materials that contain pathogens. These micro-organisms (including bacteria, viruses, parasites and fungi) and other agents can cause disease in humans or animals.
Environmentally hazardous substances
Certain materials can be a threat to the nature and adversely affect people's health. To classify them, the IATA DGR refers to the criteria for environmentally hazardous substances of the
UN Model Regulations (pdf).