National Highway Traffic Safety Administration Proposes New Electric Vehicle and Hydrogen Safety Standards

On April 15, 2024, the National Highway Traffic Safety Administration (NHTSA) published a Notice of Proposed Rulemaking (NPRM) announcing the proposed Federal Motor Vehicle Safety Standard (FMVSS) No. 305a, “Electric-powered Vehicles: Electric Powertrain Integrity.” The FMVSS replaces the current FMVSS No. 305 (“Electric-powered vehicles: Electrolyte spillage and electrical shock protection”) and harmonizes U.S. electric vehicle (EV) safety standards with global technical regulations (GTRs).

Replacing FMVSS No. 305

The proposed FMVSS No. 305a would maintain all the requirements of FMVSS No. 305 but would expand its applicability to heavy-duty vehicles (those with a gross vehicle weight rating (GVWR) greater than 10,000 pounds) and add requirements and test procedures covering new aspects of electric vehicle safety, such as the performance and risk mitigation requirements for the propulsion battery, referred to as the Rechargeable Electrical Energy Storage System (REESS). NHTSA is also proposing requirements on vehicle manufacturers to ensure that emergency responders have access to vehicle-specific information about extinguishing REESS fires and mitigating safety risks associated with stranded energy remaining in the REESS after an accident.

For light-duty vehicles (those with a GVWR of 10,000 pounds or less), FMVSS No. 305a would impose enhanced electrical system safety requirements during operation and postcrash. For heavy-duty vehicles, the new rule would impose enhanced electrical system safety requirements during operation but not postcrash. FMVSS No. 305a also contains REESS safety performance requirements on light and heavy vehicles during normal operation. For heavy school buses, the new rule imposes enhanced requirements for electrical system safety during operation, additional REESS requirements, and postcrash requirements related to unreasonable risk of electric shock and fire.

NHTSA intends to sunset FMVSS No. 305 after FMVSS No. 305a is finalized. NHTSA proposed a compliance deadline of two years after the date of publication of the final rule or three years for small manufacturers and final-stage manufacturers of heavy school buses.

Aligning With Global Technical Regulations

FMVSS No. 305a furthers NHTSA’s efforts to harmonize the FMVSSs with the United Nations Economic Commission for Europe 1998 Global Agreement (1998 Agreement), to which the U.S. is a contracting party member. In March 2012, parties to the 1998 Agreement voted to develop GTR No. 20, entitled “Electric Vehicle Safety.” NHTSA’s proposed FMVSS No. 305a largely adopts GTR No. 20 by expanding FMVSS 305 to apply to heavy vehicles, enhancing postcrash requirements for REESS retention and electrolyte leakage, and addressing some aspects of REESS safety through documentation measures.

Specific Comments Sought

Comments on the proposed rule are due June 14, 2024. NHTSA is specifically requesting public input on a number of topics including the following:

• Mechanical Integrity Test: comments on a mechanical integrity test for REESS on heavy vehicles to evaluate postcrash safety at a component level
• Mechanical Shock Test: comments to inform research on a mechanical shock test for REESS on heavy vehicles to evaluate postcrash safety at a component level, given the apparent limitations of the GTR No. 20 mechanical shock test
• Applying FMVSS No. 305a to Low-Speed Vehicles: comments on potentially applying aspects of FMVSS No. 305a to low-speed vehicles (under 25 miles per hour) to ensure a level of protection against shock and fire and ensure safe operation of the REESS
• Documentation: comments on placing the emergency response information and documentation requirements in a separate regulation rather than in FMVSS No. 305a
• Phase 2 GTR No. 20 Approaches Under Consideration by the Informal Working Group (IWG): comments on the IWG’s current approaches to (1) electrolyte release and venting from the REESS, (2) single-cell thermal runaway, and (3) REESS vibration requirements

Hydrogen Fuel Cells; Comments Due June 17

Shortly after proposing FMVSS 305a, on April 17, 2024, NHTSA published another NPRM proposing two new standards, FMVSS No. 307 (“Fuel system integrity of hydrogen vehicles”) and No. 308 (“Compressed hydrogen storage system integrity”). FMVSS No. 307 would specify requirements for the integrity of the fuel system in hydrogen vehicles during normal vehicle operations and after crashes, and FMVSS 308 would specify requirements for the compressed hydrogen storage system to ensure the safe storage of hydrogen onboard vehicles. Comments on the two proposed hydrogen vehicle standards are due June 17, 2024.

Like FMVSS No. 305a, NHTSA is proposing these standards with the goals of improving the safety requirements and better aligning U.S. regulations with global regulations (in this case, GTR No. 13). Unlike the proposed updated FMVSS 305a, these hydrogen vehicle rules do not replace or update existing U.S. regulations and do not include any emergency response disclosures — they are the first of their kind.

NHTSA believes that because the battery electric and hydrogen fuel cell regulations largely align federal standards with the existing GTRs, there will not be significant costs to original equipment manufacturers and suppliers; however, industry participants should closely evaluate these new standards and associated testing requirement to understand what effects, if any, are expected.