About Dangerous goods

Dangerous goods are substances and articles that have dangerous properties that can cause injury to people, and damage to the environment, property and other goods, unless they are correctly handled during transport. 
  
The concept of transport
The movement of goods, loading and unloading, storage and other handling that comprises an element of their transport.
 
Classification of dangerous goods
The classification system is extremely important and serves as a basis for the way in which dangerous substances are transported. Dangerous goods are defined in the Transport of Dangerous Goods Act and Ordinance as substances belonging to one of the nine classes (risk categories) in accordance with the UN system.
 
The classes are:
Class 1 Explosive substances and articles
Class 2 Gases
Class 3 Flammable liquids
Class 4.1 Flammable solids self-reactive substances and solid desensitized explosives
Class 4.2 Subtances liable to spontaneous combustion
Class 4.3 Substances wich, in contact with water, emit flammable gases
Class 5.1 Oxidizing substances
Class 5.2 Organic peroxides
Class 6.1 Toxic substances
Class 6.2 Infectious substances
Class 7 Radioactive materials
Class 8 Corrosive substances
Class 9 Miscellaneous dangerous substances and articles

There are also other classifications of substances, depending on the legislation. Substances may also have combinations of properties. They might to varying degrees be water soluble, flammable, heavy or light compared to water or air, have different viscosities, etc. In the event of a fire, substances other than those that are in transport may be formed and they may possess properties that could be dangerous to humans and the environment. A multitude of different scenarios may therefore arise in the event of accidents.
 
Regulations for the transport of dangerous goods
All types of dangerous goods transport - be it by land, sea or air - must follow the regulations for the transport of dangerous goods. The regulations also usually apply to temporary storage in warehouses, at terminals or similar.
The UN recommendations are the foundation document for all transport of dangerous goods regulations, regardless of the type of transport. This document was drawn up within the framework of the UN Economic & Social Council (ECOSOC). Based on the UN recommendations regulations are drawn up for land, sea and air transport.

Anyone who classifies, packages, or makes arrangements for the transport of dangerous goods mainly needs to apply the following regulations:
ADR/ADR-S for international/national road transport.
RID/RID-S for international/national rail transport.
IMDG code for maritime transport.
ICAO-TI (IATA-DGR) for air transport.

The objective of the regulatory work for the transport of dangerous goods is to ensure safe transport. The aim is to avoid road accidents involving dangerous goods and to reduce the probability and consequences an accidents involving dangerous substances and goods in transport. Specific authorities exist for road safety, for example, the Chinese National Road Administration; and for specific issues related to the transport of dangerous goods, for example, the Chinese Rescue Services Agency.