Answer
The International Code for the Construction and Equipment of Ships Carrying Liquefied Gases in Bulk (IGC Code) undergoes periodic revisions by the IMO Maritime Safety Committee (MSC) to accommodate alternative fuels, new cryogenic materials, and decarbonization technologies.
Major Recent & Upcoming Amendments
1. High Manganese Austenitic Steel for Cryogenic Service (MSC.523(106))
- In Force: 1 January 2026
- Scope: Replaces Table 6.3 (Plates, Sections, and Forgings for Cargo Tanks, Secondary Barriers, and Process Vessels).
- Key Change: Formally permits the use of High Manganese Austenitic Steel as an alternative material to nickel steel or stainless steel for cryogenic tanks and piping down to -165⁰C. This significantly reduces material costs for LNG and liquid gas tank construction.
2. Use of Toxic Cargoes (Ammonia) as Fuel (MSC.566(109))
- In Force: 1 July 2026
- Scope: Revisions to Chapter 16 (Use of Cargo as Fuel), specifically paragraph 16.9.2.
- Key Change: Previously, toxic cargoes were strictly prohibited from being burned as fuel on gas carriers. The amendment permits gas carriers carrying toxic cargoes (such as Ammonia in Type 2G/2PG ships) to use cargo as fuel, provided safety arrangements equal to methane/natural gas are met.
- Supporting Framework: IMO approved interim guidelines for the use of LPG cargo as fuel (MSC.1/Circ.1679) and interim guidelines for Ammonia as fuel.
3. Next major package — approved in 2026, not yet in force
At MSC 111 in May 2026, IMO approved another broad package of draft IGC Code amendments. They are intended for adoption at MSC 112 in 2026, with an intended entry into force on 1 July 2028.
Topics include:
- Carriage of CO₂ cargoes
- Cargo-tank filling limits
- Emergency Shutdown (ESD) arrangements
- Use of LPG cargo as fuel
- Clarification of alternative-fuel arrangements on gas carriers
- Certificate of Fitness-related provisions
- Various structural and operational improvements
The work originated from the comprehensive review at the CCC Sub-Committee; IMO specifically identified cargo-tank filling limits, LPG as fuel, CO₂ carriage and emergency shutdown systems among the subjects addressed.