Fleet electrification is accelerating across trucking and maritime operations, and with it comes a safety consideration traditional diesel fleets never required: electric fleet battery fire safety. Lithium-ion battery packs that power electric trucks, delivery vans, and increasingly hybrid and fully electric vessels store enormous amounts of energy in a compact footprint. When that energy escapes control through impact, a manufacturing defect, or improper charging, the result is thermal runaway, a self-sustaining chemical reaction that can ignite within seconds and reignite hours or even days after the original event (NTSB, 2020). For transportation and maritime operators evaluating electric assets, understanding this risk is not optional, it is a core compliance and operational readiness issue that touches maintenance shops, terminal operations, vessel engine rooms, and every driver or crew member who works near a high-voltage battery system. This article examines the industry impact, regulatory landscape, and practical risk reduction strategies fleet and vessel operators need to build a defensible electric fleet battery fire safety program.

Industry Impact: Electrification Meets New Fire Dynamics

Trucking fleets are adding electric box trucks, terminal tractors, and last-mile delivery vans at a growing pace, while ports and passenger vessel operators are integrating lithium-ion battery banks for propulsion, hotel loads, and hybrid power systems. The National Highway Traffic Safety Administration established its Battery Safety Initiative in 2021 specifically because electric vehicle battery fires present failure modes that differ meaningfully from conventional fuel fires (NHTSA, 2021). Unlike a gasoline or diesel fire, a lithium-ion battery fire can burn at extremely high temperatures, resist conventional suppression methods, and reignite after crews believe the incident is resolved.

The U.S. Coast Guard’s July 2025 Marine Safety Alert 14-25 shows how quickly this risk has moved from the highway into maritime operations. The alert followed a fire aboard an inspected passenger vessel after loosely crimped battery lugs overheated within an integrated lithium-ion battery bank (U.S. Coast Guard, 2025). The Coast Guard noted that the same high energy density allowing vessels to complete longer all-electric voyages also causes battery fires to burn hotter and longer once thermal runaway begins (U.S. Coast Guard, 2025). No injuries resulted from that specific incident, but the alert signals that engineering plan review, proper installation, and crew training are now baseline expectations for any vessel operator integrating battery systems.

On the highway side, the NTSB’s Safety Research Report SR-20/01 examined electric vehicle crash and non-crash fires and found that stranded energy, delayed ignition, and reignition posed direct risks to emergency responders and, by extension, to fleet personnel first on scene (NTSB, 2020). For fleet safety managers, this means a battery-involved incident does not end when the visible flames are extinguished. Vehicles and vessels may need extended monitoring and isolation before they can be considered safe to return to service.

Regulatory Implications for Transportation and Maritime Operators

Electric fleet battery fire safety sits at the intersection of several federal regulatory frameworks, and operators in transportation and maritime industries need to track all of them.

The Pipeline and Hazardous Materials Safety Administration regulates lithium batteries as a hazardous material under 49 C.F.R. Parts 171–180, and its April 2023 safety advisory notice specifically addressed the transportation of electric vehicles with lithium batteries damaged by submersion in floodwaters during extreme weather events, after saltwater exposure was linked to short-circuit battery fires during transport (PHMSA, 2023). For fleets operating in hurricane-prone regions, this guidance is directly relevant: any vehicle showing signs of flood exposure must be assessed before transport, and damaged or defective lithium batteries carry additional packaging restrictions under 49 CFR 173.185(f). Fleet operators moving damaged, defective, or recalled electric vehicles, including on car carriers, in tow, or via barge, must apply DOT’s hazard communication and packaging requirements or risk citation. PHMSA’s lithium battery guidance also affects any fleet that ships spare battery packs, replacement modules, or damaged units for warranty return (PHMSA, n.d.).

OSHA addresses the workplace side of the equation. OSHA Fact Sheet 4480 outlines the hazards lithium-ion batteries present to technicians, flammable electrolytes, high stored energy, and the potential for thermal runaway triggered by physical damage, overcharging, or manufacturing defects, and recommends applying the hierarchy of controls, starting with engineering controls such as local exhaust ventilation in battery work areas (OSHA, 2025). OSHA’s Safety and Health Information Bulletin on small and wearable lithium-ion batteries further reinforces that even lower-voltage battery-powered equipment used in warehouses and terminals requires documented storage, charging, and handling procedures (OSHA, 2019).

For maritime operators, the U.S. Coast Guard now requires that integrated lithium-ion battery systems on inspected vessels undergo engineering plan review and be fitted with supporting safety systems, tested, and inspected at installation and periodically afterward, regardless of battery bank size (U.S. Coast Guard, 2025). Vessel owners and operators are also expected to train crew members on abnormal battery conditions and conduct battery fire safety drills (U.S. Coast Guard, 2025). Vessel and fleet operators serving government contracts should also review Key Safety’s federal contracting compliance support to align battery safety documentation with contract-specific requirements.

NHTSA’s interim guidance for electric and hybrid-electric vehicles, developed for law enforcement, EMS, and fire department personnel, remains a useful reference for fleet safety managers building internal emergency response procedures, since it documents shock, toxic vapor, and delayed-ignition hazards specific to high-voltage battery systems (NHTSA, 2014). The U.S. Fire Administration supplements this with response strategy guidance addressing detection, containment, and extended monitoring for battery-involved fires (U.S. Fire Administration, n.d.). Where fleets operate battery energy storage systems to support charging infrastructure, EPA guidance on safe installation and incident response for battery energy storage systems provides an additional compliance layer (EPA, n.d.).

Taken together, these frameworks mean an electric fleet or vessel operator cannot rely on a single agency’s requirements. A defensible program addresses DOT/PHMSA hazmat transport, OSHA workplace hazard controls, USCG vessel-specific engineering and crew training, and, where applicable, EPA storage system safety.

Business Implications: Cost, Continuity, and Liability

Electric fleet battery fire safety is not only a compliance obligation; it is a direct driver of operational continuity and cost control. A single thermal runaway incident can destroy a vehicle or damage a vessel compartment beyond economical repair, and reignition risk often means a damaged asset must be isolated in a controlled area for days rather than returned to service immediately (NTSB, 2020). For fleets running tight delivery schedules or vessels operating on fixed passenger or cargo routes, that downtime translates directly into lost revenue.

Insurance and liability exposure compound the operational cost. Underwriters increasingly ask fleet and vessel operators to document battery-specific fire prevention programs, technician training records, and incident response protocols before extending or renewing coverage for electrified assets. Operators who cannot produce this documentation may face higher premiums, coverage exclusions, or claim disputes following an incident. Workforce safety adds another layer of exposure: a February 2026 OSHA letter of interpretation confirmed that workplace injuries caused by lithium-ion batteries, including burns, chemical exposure, or fire-related injuries, must be evaluated against the general recording criteria in 29 CFR 1904.7 and recorded on OSHA Forms 300, 301, and 300-A when applicable (OSHA, 2026).

Reputational risk is equally real. A battery fire aboard a passenger vessel or at a terminal involving a fleet vehicle draws public and regulatory attention quickly, particularly given the Coast Guard’s and NTSB’s active focus on this hazard category. Operators who can demonstrate a documented, regulation-aligned safety program are better positioned to respond to inquiries from regulators, insurers, and customers, and to resume operations faster after an incident. Read more fleet and maritime compliance guidance on the Key Safety LLC blog. The business case for proactive electric fleet battery fire safety is straightforward: the cost of a training program, engineered charging and storage areas, and a written emergency response plan is consistently lower than the cost of an uncontrolled battery fire, the resulting downtime, and the liability that follows.

Risk Reduction Strategies Built on the Four Safety Pillars

A defensible electric fleet battery fire safety program rests on four interconnected pillars: safety and health training, hazard prevention and control, worksite analysis, and management commitment with employee involvement.

Safety and Health Training

Technicians who inspect, charge, or repair electric vehicle and vessel battery systems need training specific to high-voltage hazards, not general electrical safety training alone. NHTSA’s interim guidance and OSHA’s lithium-ion battery fact sheet both emphasize that responders and technicians must recognize warning signs, unusual odors, swelling, excessive heat, or unusual sounds from a battery pack, before those signs escalate into thermal runaway (NHTSA, 2014); (OSHA, 2025). The U.S. Coast Guard’s safety alert specifically calls for crew training on abnormal battery conditions and periodic fire drills aboard vessels with integrated battery systems (U.S. Coast Guard, 2025).

Hazard Prevention and Control

Applying the hierarchy of controls means engineering out risk before relying on procedures or PPE. OSHA recommends local exhaust ventilation in battery work areas, cool and dry storage locations away from ignition sources, and continuous monitoring for flammable or toxic gas accumulation (OSHA, 2025). For vessels, this extends to engineering plan review of battery bank installations, properly torqued and inspected electrical connections, the root cause identified in the Coast Guard’s July 2025 incident, and fire suppression systems designed for battery chemistry rather than conventional fuel fires (U.S. Coast Guard, 2025).

Worksite Analysis

Regular inspection of battery systems, charging infrastructure, and storage areas identifies developing hazards before they become incidents. This includes visual inspection for deterioration or damage, periodic testing of installed battery systems, and documented review of any vehicle or vessel involved in a collision, grounding, or other event that could have damaged a battery pack even without visible external signs (U.S. Coast Guard, 2025); (NTSB, 2020).

Management Commitment and Employee Involvement

A written electric fleet battery fire safety program only functions if leadership visibly supports it and frontline personnel are involved in identifying hazards. This means allocating budget for engineering controls and training, incorporating driver and crew feedback into procedure updates, and ensuring emergency response plans are drilled, not simply filed. Fleet and vessel operators that build this commitment into their safety management system are best positioned to satisfy PHMSA, OSHA, USCG, and EPA expectations simultaneously, rather than addressing each requirement in isolation.

How Key Safety LLC Supports Electric Fleet Battery Fire Safety Programs

Key Safety LLC works with transportation and maritime operators to translate this regulatory landscape into a program that holds up under audit and under incident review. Through Document Development for Start-Up Projects, Key Safety builds the written battery fire safety plans, emergency response procedures, and training curricula that new electrified fleets and vessel integrations need from day one. For operators managing existing electric assets, Service on Demand provides on-site or virtual support for specific needs, coordinating an engineering plan review, conducting an OSHA-aligned hazard assessment of a charging or maintenance area, or updating an incident response protocol following a Coast Guard or NTSB advisory. Regular Consultation Services keep fleet safety managers current as PHMSA, OSHA, USCG, and EPA guidance evolves, so battery fire safety programs stay aligned with the latest federal expectations rather than falling out of date after the first audit. Explore Key Safety’s full range of EHS consulting services for transportation and maritime operators.

Take the Next Step Toward Electric Fleet Battery Fire Safety

Electric fleet battery fire safety is a moving regulatory target, and transportation and maritime operators cannot afford to treat it as an afterthought. Key Safety LLC helps fleet and vessel operators build documented, defensible battery fire safety programs aligned with OSHA, PHMSA, USCG, and EPA requirements. Contact Key Safety LLC to schedule a consultation. Subscribe to Key Safety LLC’s newsletter for ongoing regulatory updates on electric fleet and battery safety compliance.

References

National Highway Traffic Safety Administration. (2014, March). Interim guidance for electric and hybrid-electric vehicles equipped with high-voltage batteries: Law enforcement, emergency medical services, fire department (DOT HS 811 575). U.S. Department of Transportation. https://www.nhtsa.gov/sites/nhtsa.gov/files/811575-interimguidehev-hv-batt_lawenforce-ems-firedept-v2.pdf

National Highway Traffic Safety Administration. (2021, January). Battery safety initiative for electric vehicles. U.S. Department of Transportation. https://www.nhtsa.gov/battery-safety-initiative

National Transportation Safety Board. (2020). Safety risks to emergency responders from lithium-ion battery fires in electric vehicles (Safety Research Report NTSB/SR-20/01). https://www.ntsb.gov/safety/safety-studies/Documents/SR2001.pdf

Occupational Safety and Health Administration. (2025, January). Lithium-ion battery safety (OSHA FS-4480). U.S. Department of Labor. https://www.osha.gov/sites/default/files/publications/OSHA4480.pdf

Occupational Safety and Health Administration. (2019, January 18). Preventing fire and/or explosion injury from small and wearable lithium-ion batteries (Safety and Health Information Bulletin SHIB 01-18-2019). U.S. Department of Labor. https://www.osha.gov/sites/default/files/publications/SHIB011819.pdf

Occupational Safety and Health Administration. (2026, February 9). U.S. Department of Labor issues letter of interpretation on recording workplace injuries related to lithium-ion batteries [News release]. U.S. Department of Labor. https://www.osha.gov/news/newsreleases/osha-trade-release/20260209

Pipeline and Hazardous Materials Safety Administration. (n.d.). Transporting lithium batteries. U.S. Department of Transportation. https://www.phmsa.dot.gov/lithiumbatteries

Pipeline and Hazardous Materials Safety Administration. (2023, April 7). Safety advisory notice: Transportation of electric vehicles containing lithium batteries damaged by extreme weather events. U.S. Department of Transportation. https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/2023-04/PHMSA-Safety-Advisory-Transportation-of-EVs-Lithium-Batteries-April-2023.pdf

U.S. Coast Guard. (2025, July 14). Marine safety alert 14-25: Lithium-ion (Li-ion) battery system installations. U.S. Department of Homeland Security. https://www.dco.uscg.mil/Portals/9/DCO%20Documents/5p/CG-5PC/INV/Alerts/USCGSA_1425.pdf

U.S. Environmental Protection Agency. (n.d.). Battery energy storage systems: Main considerations for safe installation and incident response. https://www.epa.gov/electronics-batteries-management/battery-energy-storage-systems-main-considerations-safe

U.S. Fire Administration. (n.d.). Risks and response strategies for lithium-ion battery fires. Federal Emergency Management Agency. https://www.usfa.fema.gov/a-z/lithium-ion-batteries/risks-and-response-strategies/