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IMO Classes for Dangerous Goods

Safe Handing and Secure Transportation

IMO Classes for Dangerous Goods are a set of classifications used to identify different types of hazardous materials and their level of danger during transportation. The International Maritime Organization (IMO) has established a system that assigns each dangerous good a class based on its characteristics such as toxicity, flammability, and potential for explosion. There are nine classes in total, with Class 1 being explosives and Class 9 being miscellaneous dangerous goods. Understanding the IMO Classes is crucial for logistics and supply chain companies to ensure the safe transportation of hazardous materials, as each class has different packaging, labelling, and handling requirements. Adhering to these regulations helps to prevent accidents and ensure the safety of those involved in the transportation and handling of dangerous goods.

IMO Classes For Dangerous Goods

Classification Of Dangerous Goods

For all modes of transport (sea, air, rail, road and inland waterways) the classification (grouping) of dangerous goods, by type of risk involved, has been drawn up by the UNITED NATIONS Committee of Experts on the Transport of Dangerous Goods (UN).



Subclass 1.1

Consists of explosives that have a mass explosion hazard. A mass explosion is one which affects almost the entire load instantaneously.


Subclass 1.2

Consists of explosives that have a projection hazard but not a mass explosion hazard.


Subclass 1.3

Consists of explosives that have a fire hazard and either a minor blast hazard or a minor projection hazard or, both but not a mass explosion hazard.


Subclass 1.4

Consists of explosives that present a minor explosion hazard. The explosive effects are largely confined to the package and no projection of fragments of appreciable size or range is to be expected. An external fire must not cause virtually instantaneous explosion of almost the entire contents of the package.


Subclass 1.5

Consists of very insensitive explosives. This division is comprised of substances which have a mass explosion hazard but are so insensitive that there is very little probability of initiation or of transition from burning to detonation under normal conditions of transport


Subclass 1.6

Consists of extremely insensitive articles which do not have a mass explosive hazard. This division is comprised of articles which contain only extremely insensitive detonating substances and which demonstrate a negligible probability of accidental initiation or propagation.


Subclass 2.1

Flammable Gas 1454 kg (1001 lbs) of any material which is a gas at 20°C (68°F) or less and 101.3 kPa (14.7 psi) of pressure (a material which has a boiling point of 20°C (68°F) or less at 101.3 kPa (14.7 psi)) which- 1. Is ignitable at 101.3 kPa (14.7 psi) when in a mixture of 13 percent or less by volume with air; or 2. Has a flammable range at 101.3 kPa (14.7 psi) with air of at least 12 percent regardless of the lower limit.


Subclass 2.1.2

Non-flammable, Non-poisonus Gas This division includes compressed gas, liquefied gas, pressurized cryogenic gas, compressed gas in solution, asphyxiant gas and oxidizing gas. A non-flammable, nonpoisonous compressed gas (Division 2.2) means any material (or mixture) which- 1. Exerts in the packaging an absolute pressure of 280 kPa (40.6 psia) or greater at 20°C (68°F), and 2. Does not meet the definition of Division 2.1 or 2.3.


Subclass 2.2

Oxygen Gas This is an optional placard to the 2.2 Non-flammable Gas placard for compressed Oxygen in either the gas or liquid state. Oxygen is considered a non-flammable because it in and of itself does not burn. It is, however, required for combustion to take place. High concentrations of oxygen greatly increases the rate and intensity of combustion.


Subclass 2.3

Poison Gas 4Gas poisonous by inhalation means a material which is a gas at 20°C or less and a pressure of 101.3 kPa (a material which has a boiling point of 20°C or less at 101.3kPa (14.7 psi)) and which:

1. is known to be so toxic to humans as to pose a hazard to health during transportation, or,

2. in the absence of adequate data on human toxicity is presumed to be toxic to humans because when tested on laboratory animals it has an LC50 value of not more than 5000 ml/m3.


Flammable Liquid

A flammable liquid (Class 3) means a liquid having a flash point of not more than 60.5°C (141°F), or any material in a liquid phase with a flash point at or above 37.8°C (100°F) that is intentionally heated and offered for transportation or transported at or above its flash point in a bulk packaging..


Class 4.1

Flammable Solids or Substances Flammable Solids or Substances Desensitized explosives that when dry are explosives of Class 1 and are specifically authorized by name or have been assigned a shipping name and hazard class by the Associate Administrator. Self-reactive materials,which are thermally unstable and that can undergo a strongly exothermic decomposition even without participation of air. Readily combustible solids that can cause a fire through friction and show a burning rate faster than 2.2 mm (0.087 inches) per second, or metal powders that can be ignited and react over the whole length of a sample in 10 minutes or less.


Class 4.2

Flammable solids Flammable Solids Spontaneously Combustible material is a pyrophoric material, which is a liquid or solid that can ignite within five (5) minutes after coming in contact with air or a self-heating material that when in contact with air and without an energy supply is liable to self-heat.


Class 4.3

Substances which, in contact with water, emit flammable gases Substances which, in contact with water, emit flammable gases Dangerous When Wet material is a material that when it makes contact with water is liable to become spontaneously flammable or give off flammable or toxic gas at a rate greater than 1 L per kilogram of the material per hour.


Class 5.1

Oxidizing substances (agents) by yielding oxygen increase the risk and intensity of fire Oxidizing substances (agents) by yielding oxygen increase the risk and intensity of fire Oxidizer (Division 5.1) means a material that may, generally by yielding oxygen, cause or enhance the combustion of other materials.


Class 5.2

Organic peroxides - most will burn rapidly and are sensitive to impact or friction Organic peroxides - most will burn rapidly and are sensitive to impact or friction Organic peroxide (Division 5.2) means any organic compound containing oxygen (O) in the bivalent -O-O- structure and which may be considered a derivative of hydrogen peroxide, where one or more of the hydrogen atoms have been replaced by organic radicals.


Class 6.1

oxic substances Toxic, poison substances known to be toxic to humans so as to afford a hazard to health during transportation or is presumed to be toxic to humans because it falls within a toxic category when tested on laboratory animals. an irritating material such as tear gas that causes extreme irritation, especially in confined spaces.


Class 6.2

Infectious substances Infectious Substance material is known to contain or suspected of containing a pathogen

6.2.1 Definitions For the purposes of these Regulations: Infectious substances are substances which are known or are reasonably expected to contain pathogens. Pathogens are defined as micro-organisms (including bacteria, viruses, rickettsiae, parasites, fungi) and other agents such as prions, which can cause disease in humans or animals.


Class 7

Radioactive Substances Radioactives Any quantity of packages bearing the RADIOACTIVE YELLOW III label (LSA-III). Some radioactive materials in "exclusive use" with low specific activity radioactive materials will not bear the label, however, the RADIOACTIVE placard is required.


Class 8

Corrosives Corrosives 201. For the purpose of this subchapter "corrosive materials" (Class 8) means a liquid or solid that causes full thickness destruction of human skin at the site of contact within a specified period of time. A liquid that has a severe corrosion rate on steel or aluminum is also a corrosive material.


Class 9

Miscellaneous dangerous substances and articles Miscellaneous 2122A material which presents a hazard during transportation but which does not meet the definition of any other hazard class.

1. Any material which has an anesthetic, noxious or other similar property which could cause extreme annoyance or discomfort to a flight crew member so as to prevent the correct performance of assigned duties; or
Any material for an elevated temperature material, a hazardous substance, a hazardous waste, or a marine pollutant.