This article is to clarify doubts asked by seafarers and shoreside stowage planners. For detailed explanation of stowage and segregation on container ships click here.

What is stowage?

IMDG Code defines stowage as below.

Stowage means the proper placement of dangerous goods on board a ship in order to ensure safety and environmental protection during transport. Stowage on deck means stowage on the weather deck. For open ro-ro cargo spaces see 7.5.2.6 of IMDG Code Stowage under deck means any stowage that is not on the weather deck. For hatchless containerships see 7.4.2.1 of IMDG Code

IMDG Code 41-22 Chapter 7.1

Document of Compliance

Every ship authorized to carry dangerous goods is issued with Document of compliance under the provisions of regulation II 2/19 of the 1974 SOLAS Convention. [MSC.1/Circ.1266 of 2008] Document of compliance authorizes which class of dangerous goods are permitted in under deck spaces and on deck spaces, authorization is for packaged dangerous goods, packaged and bulk goods and NOT ALLOWED as below.

• “P” indicates – PACKAGED GOODS PERMITTED.
• “A” indicates- PACKAGED AND BULK GOODS ALLOWED.
• “X” indicates- NOT ALLOWED.

See a sample document of compliance below. (Not allowed is indicated with “-“

Question Some seafarers and shoreside stowage planners asked whether we could load any dangerous goods under deck if that class of dangerous goods is authorized as indicated by “P” in document of compliance?

Answer is “not all“, only those allowed by stowage categories assigned in dangerous goods list in chapter 3.2 of IMDG Code may be loaded under deck if same is also authorized by document of compliance.

IMDG Code Stowage Categories

Dangerous goods of classes 2 to 9 and division 1.4, compatibility group S, packed in limited quantities shall be stowed as indicated in column 16a of the Dangerous Goods List in accordance with one of the categories specified below: [ for class 1 explosives see 7.1.3.1 of IMDG Code]

In the below Document of Compliance class 5.1 is authorized in cargo spaces 1 to 6, however class 5.1s assigned with stowage categories C & D are prohibited under deck by IMDG Code.

Example

• UN 1479 Class 5.1 PG I – Category D = On Deck Only
• UN 1479 Class 5.1 PG II & III – Category B – On or Under Deck
• UN 2208 Class 5.1 PG III – Category D = On Deck Only

Which dangerous goods can be loaded under deck?

Only those assigned with stowage categories A, B & E in IMDG Code which are also permitted by vessel’s document of compliance can be loaded under deck.

Can we load dangerous goods with stowage categories C & D under deck?

Only empty uncleaned packages assigned with stowage categories C& D may be loaded under deck in a mechanically ventilated cargo space and the said class of dangerous goods is permitted by document of compliance in under deck cargo spaces. However, class 2.3 even when empty uncleaned package must be loaded on deck only and waste aerosols must be loaded according to column 16a of dangerous goods list in chapter 3.2 of IMDG Code. [See 7.1.4.1 of IMDG Code for more details]