The carriage of liquefied carbon dioxide (LCO₂) is emerging as a specialised trade with legal, technical and operational implications presenting unfamiliar risks. Unlike many liquefied gas cargoes, LCO₂ is not yet governed by mature operational conventions or a widely adopted regulatory framework, according to the Britannia Club.
Although carbon dioxide is chemically inert and non-flammable, LCO₂ poses several operational safety risks. Furthermore, while LCO₂ is not classified as a pollutant under MARPOL, large-scale releases may pose localised environmental and health hazards. CO₂ is heavier than air and can displace oxygen in confined or low-lying spaces, presenting a significant asphyxiation risk for personnel.
Shipowners and operators are encouraged to:
- Clearly define and integrate emergency response protocols into the Safety Management System (SMS)
- Engage with classification societies and flag administrations to align safety measures with prevailing standards and best practices
- Consider engaging external experts to provide training and raise preparedness among crew and technical teams where there is uncertainty or limited familiarity with LCO2-specific hazards
Cargo composition and managing impurity
Unlike food-grade CO₂, industrially captured CO₂ is more variable in quality, and may add challenges to the conditioning process before loading. Impurities such as water, oxygen, hydrogen sulfide and nitrogen oxides can lead to corrosion, pressure variability and solid formation, impacting the safety and efficiency of transport.
Operational considerations should include:
- Verifying tank material compatibility with potential corrosive compounds
- Confirming that post-conditioning LCO₂ specifications are aligned with vessel design and safe operational limits
- Assessing risks associated with shared systems e.g. common cargo piping
The present absence of standardised international guidelines for impurity levels in LCO₂ cargo presents regulatory and technical challenges that need to be addressed as the trade develops.
Cross-border and contractual considerations
LCO₂ is generally classified as “waste” and subject to varying jurisdictional controls, making early legal and technical guidance essential for cross-border compliance. The regulatory framework remains unsettled and depends on specific bilateral or multilateral agreements.
No standard charterparty exists for LCO₂ carriage. LNG models are insufficient, and bespoke terms are likely needed to address tank preparation, cargo loss tolerances, impurity specifications, terminal compatibility and transfer of title and risk.
Shipowners and charterers are also advised to stay updated on applicable requirements and the evolving risk profile of the trade, to ensure that operational practices and contractual frameworks remain properly aligned and appropriate.
Port infrastructure and readiness
Most existing port facilities for CO₂ handling are configured for small-scale, food-grade applications. It is also noted that although mature offloading technologies exist, there is currently limited demonstration of safe operationalisation by trained port personnel.
This highlights the broader challenges and readiness gap that may similarly affect dedicated LCO₂ carrier operations, particularly in early projects. As such shipowners should:
- Evaluate terminal readiness during fixture negotiations
• Confirm compatibility of terminal infrastructure with high-volume, pressurised LCO₂ offloading, agreed pumping rates, etc.
• Clarify demurrage provisions related to delays from incompatible facilities
Additional attention may be required where the delivery chain includes direct injection from the ship into an offshore storage site or transfers to offshore storage and injection platforms.
Liability frameworks: LLMC and HNS Convention
According to Britannia, for now, the main liability regime applicable to CO₂ leakage is the Convention on Limitation of Liability for Maritime Claims (LLMC). However, this framework remains untested in the specific context of LCO₂-related incidents.
The Hazardous and Noxious Substances (HNS) Convention – once in force – could apply to the carriage of LCO₂, being amongst the substances listed in the International Gas Carrier (IGC) Code.