MGN 681 (M) Amendment 1: Updates to Lithium-Ion Fire Safety Guidance into practical application on yachts MGN 681 (M) Amendment 1: Updates to Lithium-Ion Fire Safety Guidance into practical application on yachts

While these technologies offer clear operational and environmental advantages, they also introduce a fundamentally different fire risk. With the publication of MGN 681 (M) Amendment 1 (Fire Safety and Storage of Small Electric-Powered Craft on Yachts), the UK Maritime & Coastguard Agency (MCA) has taken an important step toward further clarifying how lithium-ion fire risks should be managed on yachts.

MGN 681 is a Marine Guidance Note issued by the MCA. Although it is not statutory legislation, it describes what the Administration considers to be best practice for the storage, charging, and fire protection of lithium-ion batteries used in small electric-powered craft carried on yachts.

In practice, MGN 681 is increasingly used as:

• a reference for flag state inspections and audits;
• guidance for class assessments;
• a benchmark for insurers;
• A design and refit reference for new construction and retrofit projects.

The updated version reflects a growing expectation among flag states, classification societies, and insurers that lithium-ion fire safety be addressed in a structured, verifiable, and practical manner.

To support crews during the critical early stages of a lithium-ion incident, we offer a dedicated lithium-ion fire suppression solution, designed as a practical complement to fixed fire suppression systems. This solution includes:

• 2 × 6-liter ASAP fire extinguishers, specifically designed for lithium-ion battery fires, providing effective cooling and preventing re-ignition;
• 1 × Li-Fire fire blanket (5 × 5 meters), designed to isolate battery-powered vehicles or battery packs, limit the spread of flames, and reduce heat radiation;
• 1 × LFIM (Lithium Fire Intervention & Mitigation) Intervention Kit, enabling the crew to respond in a controlled and safer manner.

These tools are consistent with the emphasis in MGN 681 (Amendment 1) on early intervention, escalation control, and crew protection. Such equipment is not a substitute for fixed fire-fighting systems, but a critical operational addition, particularly during the initial response phase.

Earlier versions of MGN 681 described principles rather than outcomes. Amendment 1 introduces much clearer functional requirements, particularly for charging and storage cabinets or containers. These solutions are now expected to provide:

• charging only when the cabinet is closed;
• over-temperature detection;
• automatic interruption of the charging process;
• the ability to apply fire suppression without opening the cabinet;
• controlled venting of toxic and flammable gases (off-gassing);
• clearly defined maximum battery capacity (kWh).

This makes it clear that basic lockers or makeshift solutions are no longer sufficient.

A significant update in Amendment 1 is the explicit classification of lithium-ion battery storage and charging cabinets as fire suppression systems. As a result:

• UK type approval or certification under the Merchant Shipping (Marine Equipment) Regulations 2025 is expected;
• As of January 1, 2027, newly installed systems are effectively required to meet these standards;
• Existing installations may remain in service, but early replacement with certified solutions is strongly recommended.

This has direct implications for both existing yachts and refit projects.

Amendment 1 places greater emphasis on:

• the risk of the fire reigniting after it has been initially extinguished;
• prolonged post-incident monitoring;
• the use of CCTV and thermal imaging cameras as supporting tools;
• gas detection as a developing—but not yet mandatory—technology.

This reflects the reality that lithium-ion fires behave very differently from conventional fires and require a different operational approach.

The updated guidance emphasizes that lithium-ion battery fires:

• can support themselves;
• may require large amounts of water for cooling;
• can generate extreme heat and toxic gases.

MGN 681 (Amendment 1) therefore continues to prioritize:

• fixed water-based fire suppression systems, with water mist identified as particularly effective;
• sufficient hydrant coverage for extended cooling operations;
• appropriate portable equipment to support the crew's initial response.

Lithium-ion fire safety isn't just about equipment. It also requires:

• a trained crew who understand the failure mechanisms of lithium-ion batteries;
• documented procedures integrated into the Safety Management System (SMS);
• drills and preparedness for both initial response and post-incident management.

Demonstrable competence is becoming just as important as technical compliance.

In practice, many yacht owners, captains, and operators are facing the same questions:

• Does our current garage or charging space still meet today's expectations?
• Is our charging or storage solution compliant with the latest MGN 681 guidance?
• How do we demonstrate compliance to the flag state, classification society, or insurers?

The updated MGN makes it clear that lithium-ion fire safety depends on the combined effect of design, equipment, procedures, and training. We therefore support yachts and projects with a practical, integrated approach, which may include:

• a compliance check against MGN 681 (M) Amendment 1;
• advice on appropriate charging and storage solutions, tailored to the vessel;
• support with risk assessments and technical documentation;
• input for SMS procedures and crew training, with a specific focus on lithium-ion risks.

Owners, operators, and project teams are welcome to Contact Us for technical advice and a customized lithium-ion fire risk assessment, tailored to their specific vessel and operational profile.

The objective is not merely to comply with the wording of the guidance, but to establish a demonstrably safe, defensible, and operationally effective lithium-ion safety strategy on board.