Why warehouse lithium-ion fires happen

Thermal runaway, a self-accelerating heat reaction, can start from internal defects, crush damage, over-charging, exposure to heat/cold, or improper charging/storage. Once a cell fails, neighboring cells ignite, producing intense heat, flames, and toxic gases (including hydrogen fluoride and other corrosive byproducts). OSHA’s 2025 fact sheet highlights these mechanisms and calls out required controls like limiting quantities, cooling, gas monitoring in large storage areas, and compliant shipping.

• In warehouses, added risk factors include:
• Bulk quantities and tight palletization that trap heat.
• Charging activities (e-bikes, tools, forklifts) near stored packs.
• Mixing damaged/returned batteries with good stock.
• Inadequate ventilation, detection, and sprinkler design for battery hazards.

FM Global’s loss-prevention data sheet for manufacturing and storage of Lithium-ion batteries provides prescriptive controls that many facilities overlook.

The rules that define “reasonable care”

Multiple codes and transport rules set expectations a prudent operator must meet. In litigation, these are often the yardsticks for negligence.

Facility & installation standards

• NFPA 855 (Installation of Stationary Energy Storage Systems) and NEC Article 706 (Energy Storage Systems) shape siting, separation, detection, ventilation, and protection for battery rooms/ESS equipment. Jurisdictions frequently adopt these into fire/electrical codes.
• UL 9540 (system listing) and UL 9540A (thermal-runaway fire propagation test) are widely referenced; modern fire codes and NFPA 855 expect electrochemical ESS to be UL 9540–listed, with 9540A test data informing fire protection and spacing.
• OSHA recognizes these consensus standards and clarifies that, although there’s no lithium-specific OSHA rule, the General Duty Clause and multiple 29 CFR 1910 standards apply (fire protection, electrical, HAZWOPER, respirators, powered industrial trucks).

Transport & warehousing standards

• 49 CFR 173.185 governs U.S. hazmat packaging, marking, and documentation for lithium cells/batteries (UN3480/UN3481 for Li-ion; UN3090/UN3091 for lithium metal). Non-compliant handling in a 3PL or cross-dock can breach federal law and the standard of care.
• UN 38.3 testing & Test Summary: Manufacturers/distributors must provide a UN 38.3 test summary for each cell/battery design – missing paperwork is a red flag for defective/gray-market product. (Updated PHMSA guidance, July 2024.)
• Air shipments of loose Li-ion batteries (UN3480, IATA PI 965) must be shipped at ≤30% state of charge unless regulators approve otherwise – critical when airfreight feeds warehouse distribution.

Bottom line: When warehouses store, charge, or transship batteries outside these frameworks and a fire or explosion follows, civil liability exposure expands quickly to shippers, importers, pack/charger makers, integrators, carriers, and site operators.

Likely liable parties in warehouse fire/explosion cases

• Cell/battery/pack manufacturers (manufacturing or design defects; inadequate warnings/BMS).
• Charger/BMS/device manufacturers (mismatched or unsafe charging profiles; thermal management failures).
• Importers/distributors/3PLs (non-compliant UN 38.3 documentation; improper packaging/marking; storage of damaged/returns).
• Warehouse operators/property managers (failure to follow NFPA/NEC, inadequate detection/ventilation/sprinklers; unsafe charging; training gaps).
• Carriers and freight forwarders (violations of 49 CFR/IATA handling rules).

Evidence that wins (and how to preserve it)

Speed matters after a battery fire. Courts expect methodical, standards-based investigations.

1. Immediate preservation & notice. Send spoliation letters to property owners, insurers, carriers, shippers, manufacturers, and any 3PL. Secure the scene and restrict cleanup until evidence experts arrive.
2. Origin & cause under NFPA 921/1033. Use qualified fire investigators and electrical engineers who follow NFPA 921 methodology to protect admissibility under FRE 702/Daubert.
3. Collect the paper trail.
   • Bills of lading, UN 38.3 test summaries, SDS, customs entries, pack lists, and supplier conformity files.
   • Training and SOPs: OSHA programs, emergency action plans, charging procedures, hazard communication.
   • Maintenance/charging logs, forklift/e-bike records, returns/RMA bins, CCTV, access control logs.
4. Forensic handling of battery debris. Maintain chain of custody; retain exemplar products. If an ESS was involved, request UL 9540A reports relied on for siting/protection decisions.
5. Injury & exposure documentation. Given HF and other toxicants, obtain prompt tox workups and respiratory assessments for exposed workers/first responders.

Damages in lithium-ion warehouse cases

• Catastrophic personal injury and wrongful death (burns, inhalation injuries, toxic exposures).
• Property losses (building, inventory, equipment) and business interruption.
• Environmental remediation and first-responder costs due to toxic effluents.
• Downstream contractual losses (supply chain delays, customer claims).
• Recent enforcement actions also show regulatory consequences when emergency planning and training fall short after a lithium fire.

Practical prevention steps (and how they play in court)

• Segregate, limit, and monitor: Quantity limits, clear separation of damaged/returns, temperature control, and continuous flammable/toxic gas monitoring in large storage.
• Engineer for the hazard: Ventilation, detection, and sprinkler designs informed by NFPA 855/NEC 706, UL 9540A data, and insurer guidance (e.g., FM Global DS 7-112).
• Ship like it matters: Verify 49 CFR 173.185 compliance, UN 38.3 test summaries on file, and the IATA ≤30% SoC rule when air is involved.
• Train and drill: Lithium-specific EAPs, HAZWOPER where applicable, respirator programs, and incident command checklists that anticipate HF and off-gassing.

Courts routinely look to these standards to define what a reasonable warehouse operator, shipper, or manufacturer should have done. Compliance, or the lack of it, often determines fault.

How we build these cases

Our catastrophic loss team pairs battery forensics with supply chain discovery to identify every responsible link – from cell design to last-mile handling. We move fast to preserve evidence, retain the right NFPA 921 experts, and quantify medical, economic, and environmental harms for full compensation.

If you or your organization suffered injuries, a loved one was lost, or your business was impacted by a lithium-ion warehouse fire or explosion, we’re here to help you stabilize, investigate, and pursue accountability with urgency and care.

Contact us today for a free consultation.