Flammability – IMDG Code Compliance Centre

Compatibility of Gases

A particular Gas may be incompatible with the cylinder or any packaging in which it is stored or with the pipelines through which it passes. For example Acetylene will react with zinc and copper, hydrogen sulphide will react with brass..

There was an incident in which an aluminium cylinder containing ethyl chloride and helium with trace amounts of 1,1,1-trichloroethane and trichloroethylene exploded in a cargo warehouse in the Dubai Airport. This was due to non-compatibility of the mixture of gases and the material of cylinder.

Two different gases may react with each other, example Acetylene, which is a highly flammable gas will dangerously react with Chlorine which is a strong oxidizing agent; water-reactive gas.

In transport regulations gases are classified as below

Class 2: Gases

Class 2.1: flammable gases

Class 2.2: non-flammable, non-toxic gases

Class 2.3: toxic gases

According to physical state transport condition of gases are divided in to four;

Compressed gas
Liquefied gas
Refrigerated liquefied gas
Dissolved gas.

While storing gas in cylinders or any pressure receptacles or while transporting or storing different gases together, one must take into consideration of below;

Compatibility of gas with the storage device (materials of the cylinder made of).
Compatibility of gases stored or transported together (chemical reactions between the gases in case of leakage of both or when involved together in fire what may be the consequences).
Compatibility of gas with other goods
Any other safety concerns

Below is the segregation table for gases as per IMDG Code, in this we can see the different clauses for transporting gas by ocean going vessels.

SEGREGATION OF CLASS 2SEGREGATION OF CLASS 2 — SEGREGATION OF CLASS 2

For sea transport one must look in to the individual provisions in IMDG Code for each gas before deciding whether it can be stored together on a ship.

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PAINT, CORROSIVE and FLAMMABLE

Paint since 1978 (Photo credit: dogwelder)

Paint or Paint removers or strippers may contain corrosive substances and other chemicals including slight oxidizers or flammable liquids.

Dried green paint (Photo credit: Wikipedia)

Paint and paint related materials having corrosive properties must be listed under any of the below UN numbers according to the properties of the specific product by using classification criteria of chapter 2 of IMDG Code.

UN 3066 Class 8 PAINT
UN 3066 Class 8 PAINT RELATED MATERIAL
UN 3469 Class 3/8 PAINT, FLAMMABLE, CORROSIVE
UN 3469 Class 3/8 PAINT RELATED MATERIAL, FLAMMABLE, CORROSIVE
UN 3470 Class 8/3 PAINT, CORROSIVE, FLAMMABLE
UN 3470 Class 8/3 PAINT RELATED MATERIAL CORROSIVE, FLAMMABLE

Paint or Paint related materials having only flammable property must be declared under

UN 1263 Class 3 PAINT or
UN 1263 Class 3 PAINT RELATED MATERIAL

Dave’s WW of EU: Flammable, inflammable, non-flammable (daveloveless.wordpress.com)

AIR CONDITIONERS AND REFRIGERATORS

Multi-Compressor-Rack-Refrigeration__46075 (Photo credit: Public Domain Photos)

Refrigerating machines are considered as dangerous goods for sea transport. Refrigerating machines may either contain non-flammable non-toxic gasses, ammonia solution or flammable, non-toxic, liquefied gas.

There are two entries for refrigerating machines in IMDG Code 35-10

UN 2857, Class 2.2

REFRIGERATING MACHINES containing non-flammable, non-toxic gases or ammonia solution (UN 2672)

UN 3358 , Class 2.1

REFRIGERATING MACHINES containing flammable, non-toxic, liquefied gas

There are also exemptions in IMDG Code for Refrigerating machines.

Compressed Air, & Air, Refrigerated Liquid

DG Reefer – Commercial Reasons

Certain Dangerous Goods require mandatory transport in reefer containers due to safety reasons. These are some of the Self-reactive Substances under Class 4.1 and some of the Organic Peroxides, Class 5.2. This requirement is listed in column 16 of DG List in chapter 3.2 and respective sub sections in chapter 2.4 & 2.5 of IMDG Code (35-10).

Let us look at the provisions of other dangerous goods which do not require refrigerated containers but are offered sometimes as temperature controlled.

So what goods which do not require a reefer is sometimes transported in reefer? Generally these are Perfumes ( UN 1266), Safety Matches ( UN 1944), Paint (UN 1263), Lithium Batteries (UN 3090,3091,3480,3481). Some shippers transport these in live reefers to maintain the product quality. Of course Calcium Hypochlorite require live reefers by most of the shipping lines due to its bad past.

IMDG Code has certain provisions for Dangerous Goods in reefers for commercial reasons, these are specifically related to Flammable Gases ( Class 2.1) and Flammable liquids ( Class 3). When Flammable liquids having flashpoint less than 23 °C c.c is transported in live reefer then

1/ Substance shall be precooled and

2/ Transported at a temperature at east 10 Deg C below its flashpoint

Or explosion proof reefer is required.

At any moment during transport In case the reefer fails then power supply shall be disconnected and must not be switched on again.

No line will accept flammable gas in live or non-live reefers. ( For full details refer 7.7 of IMDG Code)

Dangerous Goods Classes, Divisions, Marine Pollutants, Packing Groups and Wastes

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

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