Overview

As the global new energy industry flourishes, international trade volume in lithium batteries and related products continues to climb. According to statistics, global lithium battery maritime exports exceeded 1.5 million metric tons in 2026, more than three times that of five years prior, with nearly 70% originating from Chinese factories. However, as dangerous goods, lithium batteries face comprehensive tightening of maritime safety regulation globally. The International Maritime Organization (IMO) passed amendments to the International Maritime Dangerous Goods (IMDG) Code in 2025, making significant updates to lithium battery classification standards, packaging requirements, marking and labeling, and declaration documents. This article systematically reviews the core changes in the new IMDG rules, compliance key points for lithium battery maritime transport, common violation risks, and practical recommendations, providing comprehensive compliance guidance for international logistics, ocean freight, air freight, and freight forwarding service practitioners.

1. Core Background of IMDG Code Amendments

1.1 Frequent Lithium Battery Maritime Incidents Drive Regulatory Upgrade

Over the past five years, more than 20 major lithium battery maritime safety incidents have occurred globally. In 2024, a container ship in the Atlantic Ocean suffered severe damage and casualties due to a lithium battery thermal runaway fire inside a container, triggering widespread industry concern about lithium battery maritime safety. Once thermal runaway occurs, lithium batteries can release large amounts of heat and combustible gases within seconds, making them difficult for traditional fire suppression systems to effectively suppress—this is a major hidden danger for ship safety operations. Therefore, when revising the IMDG Code in 2025, the IMO comprehensively upgraded lithium battery supervision levels.

1.2 Coordinated Promotion of Environmental and Safety Requirements

In addition to safety considerations, under the framework of MARPOL and the Hong Kong International Convention for the Safe and Environmentally Sound Recycling of Ships, the IMO has also strengthened requirements for lithium battery full life-cycle environmental compliance. New rules explicitly require that equipment containing lithium batteries meet specific environmental standards when scrapped and recycled, while providing guidance on the recyclability of lithium battery transport packaging materials. The coordinated supervision trend of safety and environmental protection means enterprises need to examine lithium battery supply chain compliance from a more comprehensive perspective.

2. Core Changes in the New IMDG Code

2.1 Refined Lithium Battery Classification Standards

The new IMDG Code has made major refinements to the lithium battery classification system. Previously, lithium batteries were mainly divided into two categories—"lithium ion batteries" and "lithium metal batteries." The new rules introduce the distinction between "lithium battery cells" and "lithium battery devices," and add a three-dimensional classification matrix based on capacity, voltage, and chemical system. Specifically:

| Classification Dimension | Specific Category | Applicable Rules |

|------------------------|-------------------|-----------------|

| Electrochemical System | Lithium ion (Li-ion), Lithium metal (Li-metal) | Different packaging directives; Li-metal has stricter restrictions |

| Structural Form | Cell, Battery Pack, Device | Device category may apply special simplified packaging |

| Capacity/Voltage | Small (<100Wh/≤300V), Large (≥100Wh and <160Wh/≤300V) | Large batteries must meet stricter packaging and declaration requirements |

| Sodium Ion Batteries | New sodium ion (Na-ion) category added | Applicable specific packaging directives starting 2026 |

2.2 Comprehensive Upgrade of Packaging Requirements

The new rules impose stricter technical requirements on lithium battery transport packaging. First, packaging materials must meet UN38.3 certification standards, meaning they must pass eight extreme condition tests including altitude test, temperature cycling test, vibration test, shock test, external short circuit test, impact test, overcharge test, and forced discharge test. Second, for large-scale lithium ion battery packs (with total cell weight exceeding 50kg per package), the new rules require packaging performance standards at or above Class II (upgraded to Class I standard from July 2026), with mandatory installation of independent ventilation systems and thermal runaway suppression devices.

Additionally, the new rules mandate updates to packaging markings. All lithium battery transport packaging must have "Caution—Contains Lithium Batteries" warning text clearly marked on the outer surface, along with a specifically formatted lithium battery mark (red background with white text, with distinct graphic requirements from the old version). For recycled or end-of-life lithium batteries, packaging must additionally bear the words "Waste Lithium Batteries" and must not share the same packaging batch with ordinary lithium batteries.

2.3 Declaration Documents and Port Operation Requirements

The new rules strengthen the declaration document system for lithium battery maritime transport. Shippers must submit a complete Dangerous Goods Declaration to the shipping company and port at least 24 hours before loading, clearly stating the UN number of the lithium battery (e.g., UN3480 for lithium ion batteries, UN3090 for lithium metal batteries), danger class, packaging group, and emergency contact information. Shipping companies have the right to inspect suspected undeclared or misdeclared containers, with all resulting costs borne by the shipper.

At the port operation level, the new rules require specialized Dangerous Cargo Container Yards equipped with temperature monitoring and fire suppression systems. Lithium battery containers must maintain specified safe distances from other dangerous goods containers, and mixing with oxidizers, compressed gases, and other high-risk categories is prohibited.

3. Practical Compliance Key Points

3.1 Pre-Export Compliance Checklist

Before arranging maritime transport, lithium battery export enterprises should complete the following compliance self-checks item by item: confirm the product has obtained a valid UN38.3 test report; verify the packaging supplier holds packaging performance certificates compliant with IMDG requirements; check that packaging exterior markings are clear, complete, and consistent with declaration documents; confirm declaration documents have been reviewed by the freight forwarder or shipping company; understand special import requirements of destination countries (such as US DOT special rules, EU ATEX directives, etc.).

3.2 Packaging Material Selection and Procurement

Compliant lithium battery transport packaging must be procured through professional suppliers. Enterprises should verify suppliers' UN certification qualifications and packaging performance level certification documents. For large lithium battery packs, composite packaging materials with independent relief valves and fire-retardant linings are recommended; for small lithium batteries, certified paper-wood composite boxes or plastic reusable boxes can be used. In the packaging procurement process, never choose uncertified alternative packaging to save costs—once an accident occurs during transport, insurance claims and legal liability will face significant risks.

3.3 Coordination with Freight Forwarders

Compliance responsibilities for lithium battery maritime transport are jointly borne by shippers and carriers, but shippers bear the ultimate responsibility for the authenticity of declaration information. Freight forwarders play a key coordinating role in lithium battery cargo booking, document preparation, and port declaration. It is recommended that lithium battery export enterprises select freight forwarders with DG (Dangerous Goods) professional qualifications and provide complete Material Safety Data Sheet (MSDS/SDS) and UN38.3 test reports to the forwarder at the booking stage to avoid declaration delays or shipping company rejections due to missing information.

4. Future Regulatory Trend Outlook

4.1 Diversification of National Import Requirements

As lithium battery international trade volume rises, import requirements among major importing and exporting countries are showing a divergence trend. The EU has mandatory requirements starting in 2026 for imported lithium batteries to provide carbon footprint declarations and battery passports; the US requires batteries exceeding certain capacity to obtain DOE (Department of Energy) certification; Indonesia has implemented more stringent pre-inspection systems for imported lithium batteries. Export enterprises must closely monitor dynamic regulatory changes in target markets and adjust product and packaging designs in advance to meet diverse compliance requirements.

4.2 Digital Declaration and Traceability

The IMO is actively promoting the process of digital declaration (e-DG Declaration) for maritime dangerous goods. Starting in 2026, 15 major ports have accepted electronic declaration formats, with global full adoption across major ports expected by 2028. Digital declaration not only improves efficiency but can also achieve full-chain traceability of dangerous goods through blockchain technology, creating a technical deterrent against undeclared or falsified declarations. Lithium battery export enterprises should layout digital compliance capabilities in advance to adapt to the future intelligent regulatory trend.

Conclusion

The comprehensive upgrade of lithium battery maritime rules has raised higher requirements for every participant in the international logistics supply chain. Shippers must ensure complete product testing certification, compliant packaging, and accurate documents; freight forwarding enterprises must enhance DG professional capabilities and assist clients with compliant declarations; shipping companies and ports must strengthen dangerous goods management and operation standards. In an era that values both safety and efficiency, compliance is not a burden but an important component of an enterprise's core competitiveness.