On September 26, 2025, the Ministry of Land, Infrastructure, Transport and Tourism (MLIT) made an important announcement that it will significantly improve the safety of electric vehicles (EVs) and plug-in hybrid vehicles (PHEVs). The revision of road transport vehicle safety standards, etc., will make it mandatory to conduct tests to confirm occupant protection performance in the event of a battery fire, marking the start of a groundbreaking initiative to achieve both the further spread of electric vehicles and the assurance of their safety.
Background to the introduction of new standards and international efforts
Japan’s world-leading electric vehicle safety standards
Japan has demonstrated international leadership in ensuring the safety of electric vehicles by formulating the world’s first standards for ensuring occupant safety in electric vehicles in 2007. Based on this track record, Japan proposed the new standards at the United Nations World Forum for Harmonization of Vehicle Regulations (WP.29) in March 2025, and international agreement was achieved.
Advances in battery technology and safety demands
With the rapid spread of electric vehicles, high-energy-density lithium-ion batteries have come into widespread use. However, there have been rare cases of fires caused by thermal runaway in batteries, raising the need for stricter safety standards.
Details of the new standard and technical requirements
Testing to verify occupant protection performance in the event of a battery fire
The new standards require batteries used in electric vehicle traction motors to undergo the following strict safety tests:
Test Method
- Intentional battery overheating, such as by irradiating it with a laser
- Exposing some battery cells to abnormal heat to evaluate the overall impact
- A detailed investigation into whether there was a fire, explosion, or smoke entering the vehicle
Necessary safety requirements (one of which must be met)
- Fully protected: The entire battery does not overheat
- Temperature control by thermal management system
- Mechanism to prevent heat transfer between cells
- Efficient operation of the cooling system
- Early warning/time-saving type: Activation of warning system by detecting abnormal heat
- Immediate warning signal to the driver
- A 5-minute safety period is ensured from the start of the warning
- Complete prevention of fires, explosions and smoke emissions into the vehicle interior
Application schedule and applicable vehicles
New models: Application starts from September 2027.
Continuing production models: Application starts from September 2030.
This phased introduction will provide automakers with sufficient preparation time, allowing them to systematically advance technological development and build mass production systems.
Impact on the electric vehicle industry and expected effects
Improving consumer confidence and promoting widespread adoption
The new standards are expected to have the following effects:
Greatly improved safety
- Minimizing the risk of battery fires
- Extended time for crew safety
- Ensuring time for evacuation in case of an emergency
Positive impact on the market
- Increased consumer confidence in electric vehicles
- Reduced safety concerns when considering a purchase
- Promoting healthy expansion of the electric vehicle market
Promoting technological development by automobile manufacturers
The new standards require manufacturers to innovate in the following areas of technology:
Advances in Battery Management Systems (BMS)
- Real-time Temperature Monitoring Technology
- Predictive Anomaly Detection Algorithm
- Rapid Warning System
Advances in thermal management technology
- Efficient Cooling System Design
- Development of heat insulating and heat shielding materials
- Cell placement optimization
Significance as an international standard and future prospects
The path to becoming a global standard
The new standards are based on an agreement reached at the United Nations World Forum for Harmonization of Vehicle Regulations (WP.29), and there is a high possibility that similar standards will be adopted in other countries in the future. By making Japan’s proposal an international standard, it is expected that it will also contribute to improving the competitiveness of Japan’s automotive industry.
An important step towards realizing an electrified society
The widespread use of electric vehicles is essential to achieving the carbon neutral target by 2050. Ensuring safety is a prerequisite for widespread adoption, and these new standards will serve as an important foundation for building a sustainable transportation system.
Summary: The future of electric vehicles combines safety and innovation
The introduction of new safety standards by the Ministry of Land, Infrastructure, Transport and Tourism is a groundbreaking initiative that will simultaneously improve the safety of electric vehicles and promote their widespread adoption. The gradual implementation of the standards, which will begin in September 2027, will enable consumers to choose safer electric vehicles and manufacturers to increase their competitiveness through technological innovation.
This new standard will once again establish Japan as a world leader in electric vehicle safety and will mark a major step forward in realizing a sustainable mobility society. It is an extremely important step forward, as it will create an environment in which consumers considering electric vehicles can make a more secure choice.
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