IBC instructions, other than IBC 520, in IMDG Code does not indicate maximum quantity permitted. How do we decide how much quantity can be filled in an IBC or what maximum size of IBC is permitted for a cargo?

Chapter 1.2, Definitions, of IMDG Code sets the maximum capacity of IBCs as below

• not more than 3.0 m3 (3,000 litres) for solids and liquids of packing groups II and III; 
• not more than 1.5 m3 for solids of packing group I when packed in flexible, rigid plastics, composite, fibreboard or wooden IBCs;
•  not more than 3.0 m3 for solids of packing group I when packed in metal IBCs;
• not more than 3.0 m3 for radioactive material of class 7;

 Let us check quantity limitation for below cargo

UN 1993 packing group I is not permitted in IBC as there is no IBC instruction in column 10 of Dangerous Goods list in chapter 3.2 of IMDG Code. For packing groups II and III IBC02 and IBC03 is listed respectively without setting the limit of volume.

Both IBC02 and IBC03 does not mention maximum quantity permitted. However interpreting chapter 1.2 definition, for packing group II & III we can use and IBC with capacity not more than 3.0 m3 (3,000 litres).

Do we need to keep sufficient Ullage in IBC?

Ullage means the space between top of liquid and top of the drum, IBC or tank.

Packages and IBCs must not be filled to such a level that leakage or permanent distortion of the packaging can take place as a result of an expansion of the liquid caused by temperatures likely to occur during transport, this can be achieved by keeping sufficient ullage. Liquids must never completely fill a packaging at a temperature of 55°C.

For IBCs sufficient ullage must be left to ensure that at the mean bulk temperature of 50°C it is not filled to more than 98% of its water capacity.

For a differing temperature, the maximum degree of filling may be determined as follows:

Above explanation is very generic for basic understanding. For actual shipments we must look at the individual entries in IMDG Code and comply with IBC Instructions and IBC Provisions when deciding type of IBC and maximum quantity of cargo to be filled in conjunction with the actual capacity of IBC.