In dangerous goods transport regulations⁺ of sea, IMDG Code, substances (including mixtures and solutions) and articles are assigned to one of the classes 1 to 9 according to the hazard or the most predominant of the hazards they present. Some of these classes are subdivided into divisions.

These classes or divisions are as listed below:

Class 1: Explosives

Division 1.1: substances and articles which have a mass explosion hazard

Division 1.2: substances and articles which have a projection hazard but not a mass

explosion hazard

Division 1.3: substances and articles which have a fire hazard and either a minor

blast hazard or a minor projection hazard or both, but not a mass

explosion hazard

Division 1.4: substances and articles which present no significant hazard

Division 1.5: very insensitive substances which have a mass explosion hazard

Division 1.6: extremely insensitive articles which do not have a mass explosion

Hazard

Class 2: Gases

Class 2.1: flammable gases

Class 2.2: non-flammable, non-toxic gases

Class 2.3: toxic gases

Class 3: Flammable liquids

Class 4: Flammable solids; substances liable to spontaneous combustion; substances which, in contact with water, emit flammable gases

Class 4.1: flammable solids, self-reactive substances and solid desensitized

Explosives

Class 4.2: substances liable to spontaneous combustion

Class 4.3: substances which, in contact with water, emit flammable gases

Class 5: Oxidizing substances and organic peroxides

Class 5.1: oxidizing substances

Class 5.2: organic peroxides

Class 6: Toxic and infectious substances

Class 6.1: toxic substances

Class 6.2: infectious substances

Class 7: Radioactive material

Class 8: Corrosive substances

Class 9: Miscellaneous dangerous substances and articles

The numerical order of the classes and divisions is not that of the degree of danger.

Marine Pollutants

As per IMDG Code any substance which are subject to the provisions of Annex III of

MARPOL 73/78, as amended is a MARINE POLLUTANT. These substances or articles are identified as such in column 4 of Dangerous Goods List in Volume 2 of the said Code.

Packing Groups

For packing purposes, substances* are assigned to three packing groups in accordance with the degree of danger they present:

Packing group I: substances presenting high danger;

Packing group II: substances presenting medium danger; and

Packing group III: substances presenting low danger.

*classes 1, 2, 5.2, 6.2 and 7, and self-reactive substances of class 4.1 are not assigned with Packing Groups

Wastes

While transporting wastes by sea the goods shall be assigned to the class or division considering their properties and shall be consigned as per the relevant rules. However when wastes not subject to any criteria of IMDG Code but belonging to the notification requirement of BASEL Convention may be transported as Class 9

⁺ Based on UN Model Regulations, for latest edition click here