IMDG Amendment 36-12 can be used voluntarily from 1 January 2013 ; will become mandatory from 1 January 2014.
List of UN numbers are up to 3506 and there are significant changes to Stowage and segregation, Sources of heat, Foodstuffs, Limited quantities and Explosives.
Part 7 has gone through a major shuffling by changing the order of subsections and chapters.
You may visit http://www.imdgsupport.com/ to get details of changes highlighted by Exis Technologies.
Part 7 of IMDG Code 36th amendment , especially chapters 7.1 and 7.2, is extensively rearranged so as to make the stowage and segregation provisions more user friendly while referring. The main changes are made by re arranging otherwise scattered provisions in an orderly sequence.
To view the comparison table of Part 7 in 35th and 36th Amendment of IMDG Code click here
For stowage purpose IMDG Code recommends away from “Sources of Ignition” for some classes or substances.
Sources of Ignition includes
* Certified safe type as per SOLAS II-2/19.3.2 excluded
# Explosion proof electrical fittings excluded
Above is not an exhaustive list.
General Stowage Precautions
General stowage precautions for goods of class 2 is addressed in chapter 7 section 7.1.8.1 of IMDG Code. Requirement also addresses section 7.4.2.5.2. for gases loaded in containers which may cause oxygen depleted or enriched atmosphere inside containers.
Specific Stowage Requirements
Specific stowage requirement of each dangerous goods is listed in Column 16 of Dangerous Goods List in Chapter 3.2 of IMDG CodE.
Class 2.2 may be allowed on deck or under deck or may only be allowed on deck in specific cases
Example 1 : 1002 AIR, COMPRESSED Class 2.2 – Stowage Category A. ( ON DECK OR UNDER DECK )
Example 2 : 1963 HELIUM, REFRIGERATED LIQUID Class 2.2 – Stowage Category D. ( ON DECK ONLY )
From above examples we understand that certain class 2.2 is allowed on or under deck but certain class 2.2 is allowed only on deck.
Hence it is imperative that we must look at stowage category for each dangerous goods to ascertain the particular stowage requirement.
When UN 2211 and UN 3314 are loading on board vessels IMDG Code stowage instruction states
Shaded from radiant heat and protected from sparks and open flame. When stowed under-deck, mechanical ventilation shall be in accordance with SOLAS regulation II-2/19 (II-2/54) for flammable liquids with flashpoint below 23°C (c.c).
These UN numbers are assigned with stowage category E, which means ON DECK or UNDER DECK on Cargo ships or passenger ships carrying a number of passengers limited to not more than 25 or to 1 passenger per 3 m of overall length, whichever is the greater number and prohibited on passenger ships in which the limiting number of passengers transported is exceeded
Though both UN 2211 and UN 3314 are assigned to class 9 for segregation purpose one must consider this as class 3 but separated from class 1 except 1.4S
For the purpose of stowage of dangerous goods IMDG Code divides the ships into two groups
Passenger ships are categorized as
“passenger ships carrying a number of passengers limited to not more than 25 or to 1 passenger per 3 m of overall length, whichever is the greater number
Or
“Other passenger ships in which the limiting number of passengers transported is exceeded”
Individual dangerous goods are assigned with stowage categories A, B, C, D, or E in the Dangerous Goods List in IMDG Code and these are specifically assigned for On Deck, Under Deck or whether prohibited on passenger ships.
See stowage categories of IMDG Code here
Stowage categories A to E are for goods other than Class 1 (Explosives).
For Class 1 explosives there is another set of stowage categories as shown in below images.
Section 7.1.7.5 of IMDG Code describes in full the conditions of stowage of explosives in passenger ships.
Below is quoted from IMDG Code
7.1.7.5 Transport of goods of class 1 on passenger ships
7.1.7.5.1 For the purpose of stowage in this class, the terms “passenger ship” and “cargo ship” are used as in SOLAS 1974, as amended.
7.1.7.5.2 Explosives in division 1.4, compatibility group S, may be transported in any amount on passenger ships. No other explosives may be transported on passenger ships except any one of the following:
7.1.7.5.3 Notwithstanding the provisions of 7.1.7.5.2, additional quantities or types of goods of class 1 may be transported in passenger ships in which there are special safety measures approved by the competent authority.
7.1.7.5.4 Articles in compatibility group N shall only be allowed in passenger ships if the total net explosives mass does not exceed 50 kg per ship and no other explosives apart from Division 1.4, compatibility group S, are transported.
7.1.7.5.5 Goods of class 1 which may be transported in passenger ships are identified in the Dangerous Goods List. They shall be stowed in accordance with the following table:
Before going into the physics of flashpoint we must know that flashpoint is a very important point in determining stowage of flammable liquids on board vessels. Document of Compliance specifies the holds for carriage of flammable liquids on the basis of flashpoint.
IMDG Code defines flashpoint as the lowest temperature of a liquid at which its vapour forms an ignitable mixture with air.
Wikipedia: The flash point of a volatile material is the lowest temperature at which it can vaporize to form an ignitable mixture in air. Measuring a flash point requires an ignition source. At the flash point, the vapor may cease to burn when the source of ignition is removed.
Let us see two examples of flashpoint
Petrol: -43 Deg C
Diesel: > 62 Deg C
If we light a match and bring it on the surface of petrol (DO NOT TRY IT) the vapours will flash but if same match is brought above diesel it won’t flash unless if diesel is heated at or above its flash point.
This shows that as long as the temperature of a liquid is below its flashpoint it will not have flammable hazard.
To determine the flash point there are various equipments. The liquid to be tested will be kept in a receptacle well below the expected flashpoint and heated slowly while bringing an open flame above its surface the lowest temperature the flash takes place is flashpoint. There are main two differences in this test, open-cup and closed cup. Where ever in IMDG Code a flashpoint is mentioned for any substance the figure is closed-cup.
Consignments of dangerous goods which have flashpoint at or below 60 deg C need to contain the flash point in closed-cup on the declaration.
IMDG Code Compliance Centre 