Dangerous goods –

All substances of an inflammable nature which are liable to spontaneous
combustion either in themselves or when stowed next to other substances and, when mixed with air, are liable to generate explosive gases or produce suffocation or poisoning or tainting of foodstuffs.

The International Maritime Dangerous Goods (IMDG) Code lists over 3000 hazardous substances. Goods can be categorized as dangerous for any of the following reasons:

• Because they require special care and handling in transit.
• Because their properties are harmful to human life.
• Because they possess qualities or create risks that could expose the carrier to liabilities
  or losses neither acknowledged nor agreed in the contract of carriage.
• Because they could cause damage to the ship holds or machinery.
• Because their properties require excessive expenditure by the carrier to guarantee
  safe transport.
• Because, if they escape from the ship, they are likely to cause environmental damage.
  The environmental aspect is the most frequently quoted when cargoes are classified as hazardous or noxious.

Dangerous goods classes –

Classes of dangerous goods according to SOLAS (Chapter VII, Part A), the BC-Code and the IMDG-Code, are as follows:

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.
Subdivision 1.4S contains substances and articles so packaged, or designed, that any hazardous effects arising from accidental functioning are confined within the package unless the package has been degraded by fire, in which case all blast or projection effects are limited to the extent that they do not significantly hinder fire-fighting or other emergency response efforts in the immediate vicinity of the package.

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, compressed, liquefied or dissolved under pressure

Class 2.1 Flammable gases

Class 2.2 Non-flammable, non-toxic gases

Class 2.3 Toxic (poisonous) gases

CLASS 3 – Flammable liquids

Flammable liquids are grouped for packing purposes according to their flashpoint, their boiling point, and their viscosity.

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

Class 4.1 Solids having the properties of being easily ignited by external sources,such as spark and flames, and of being readily combustible, or of being liable to cause or contribute to a fire or cause one through friction.

Class 4.2 Solids or liquids possessing the common property of being liable
spontaneously to heat and to ignite.

Class 4.3 Substances which, in contact with water, emit flammable gases.

CLASS 5 – Oxidising substances (agents) and organic peroxides

Class 5.1 Substances which, although themselves are not necessarily combustible, but may, either by yielding oxygen or by similar processes, increase the risk and intensity of fire in other materials which they come into contact with.

Class 5.2 Organic peroxides

CLASS 6 – Toxic and infectious substances

Class 6.1 Toxic substances liable either to cause death or serious injury or to harm health if swallowed or inhaled, or by skin contact.

Class 6.2 Infectious substances.

CLASS 7 – Radioactive materials

CLASS 8 – Corrosive substances

Substances, which, by chemical action, will cause severe damage, when in
contact with living tissue or, in case of leakage, will materially damage, or
even destroy, other goods or the means of transport. Many substances are
sufficiently volatile to emit vapour irritating to the nose and eyes.

CLASS 9 – Miscellaneous dangerous substances and articles

Example of dangerous goods intended to be carried onboard some vessel:-

P – Packaged goods permitted
C – Packaged goods in closed freight containers only permitted
A – Packaged and solid bulk goods permitted
B – solid bulk goods permitted
X – NOT PERMITTED

IMO Class	Description	Hold No 1	Hold No 2	Hold No 3
Class 1	Explosives	X	X	C
Division 1.1	Having a mass explosion hazard	X	X	C
Division 1.2	Having a projection hazard	X	X	C
Division 1.3	Having a fire hazard, a minor blast hazard or projection hazard	X	X	C
Division 1.4	Present no significant hazard	X	X	C
Division 1.4S		X	X	C
Division 1.5	Very insensitive substances which have a mass explosion hazard	X	X	C
Division 1.6	Extremely insensitive articles which do not have a mass explosion hazard	X	X	C
Class 2	Gases
Class 2.1	Flammable gases	X	X	C
Class 2.2	Non-Flammable Gases	X	X	C
Class 2.3	Poisonous Gases	X	X	C
Class 3	Flammable Liquids
Packing I	Liquid having flashpoint below 18°C	X	X	C
Packing II	Liquid having flashpoint 18°C upto 23°C	X	X	C
Packing III	Liquid having flashpoint above 23°C upto 61°C	X	X	C
Class 4
Class 4.1	Flammable Solids	A	A	C
Class 4.2	Substances liable to spontaneous combustion	A	A	C
Class 4.3	Substance which in contact with water emit flammable gases	A	A	C
Class 5.1	Qxidizing substances	A	A	C
Class 5.2	Organic Peroxides	X	X	C
Class 6.1	Poisonous (toxic) substances
	6.1 Liquids	P	P	C
	6.1 Liquids having flashpoint up to 23°C	P	P	C
	6.1 Liquids having flashpoint above 23°C up to 61°C	P	P	C
	6.1 Solids	A	A	C
Class 6.2	Infectious Substances	X	X	C
Class 7	Radioactive Materials	X	X	X
Class 8	Corrosives
	8 Liquids	P	P	C
	8 Liquids having flashpoint up to 23°C	P	P	C
	8 Liquids having flashpoint above 23°C up to 61°C	P	P	C
	8 Solids	A	A	C
Class 9	Miscellaneous Dangerous Substances	A	A	C