⚡ EV & Energy Storage Emergencies

EV Tactical
Reference

Hardcoded reference data for training — thermal runaway, chemistry, off-gases, water, ERG distances, and vehicle data.

⚠ For Training Use Only — Not for Use During Live Incidents

Thermal runaway in lithium-ion batteries is a self-reinforcing exothermic chain reaction that propagates cell-to-cell once it begins. It does not progress linearly — conditions can accelerate rapidly. Recognition of the stage determines the tactical window available. Use these stages to calibrate expectations, not to predict timing.

Stage 1
Early Warning

Stage 2
Venting

Stage 3
Active Runaway

Stage 4
Fire Involvement

Stage 5
Post-Fire

Early Warning / Pre-Venting

TIC (Thermal Imaging Camera) Surface Reading: 80–120°F — slightly above ambient

Visual Signs

BMS (Battery Management System) warning light illuminated. Subtle deformation or swelling above battery area. No visible smoke. Possible minor fluid weeping from battery enclosure seams.

Sounds

Minor clicking or isolated popping sounds from battery area. May be intermittent. Early electrolyte expansion within cells.

Odor

None, or very faint chemical/sweet odor. Occupants may report unusual smell from HVAC.

Gases Present

Minimal — trace electrolyte vapor only if venting has begun. Below detectable thresholds in open-air conditions.

Tactical Action

Do not dismiss BMS alerts. Establish monitoring position upwind. Remove occupants from vehicle — do not allow re-entry. Begin atmospheric monitoring. Request hazmat if available. Consider isolation perimeter even with no visible signs.

Critical Point

Internal cell temperatures may be 2–3× higher than surface TIC readings at every stage. Surface temp is a lagging indicator, not a leading one.

Active Venting / Pre-Ignition

TIC Surface Reading: 120–300°F — rapidly rising

Visual Signs

White or gray vapor from battery area — this is venting electrolyte and decomposition gas, NOT combustion smoke. Possible swelling of vehicle body panels over pack. Condensation on nearby surfaces.

Sounds

Continuous hissing or gurgling. Repeated popping as individual cells vent. Pressure relief events audible. Volume and frequency increasing.

Odor

Sharp chemical odor. Sweet-chemical smell from electrolyte. Possible acrid burning smell.

Gases Present

CO, HF, HCN (early concentrations), flammable electrolyte vapors, CO₂. LEL (Lower Explosive Limit) alarm may activate before toxic gas alarms — atmosphere is simultaneously flammable AND toxic.

Tactical Action

SCBA (Self-Contained Breathing Apparatus) required immediately — flammable and toxic atmosphere forming. Expand isolation perimeter. Eliminate all ignition sources. Do NOT open vehicle doors or windows (restricting oxygen access to the pack area is preferable). Begin continuous atmospheric monitoring. Notify hazmat if not already responding.

Critical Point

The LEL alarm threshold can be reached while CO, HF, and HCN are simultaneously at dangerous concentrations. A 4-gas meter alarming on LEL does not tell you what toxic species are present. Specific detection for HF and HCN is required.

Active Thermal Runaway

TIC Surface Reading: 300–600°F+ — rapidly escalating; surface readings underestimate internal temperatures

Visual Signs

Rapidly escalating heat visible on TIC. Possible flames from battery vent openings. Visible propagation — heat spreading laterally across battery pack footprint on TIC display.

Sounds

Loud, continuous venting. Rapid sequential popping or cracking as cells rupture. Possible jet-like sounds from vent gas ignition.

Odor

Intense chemical odor. Strong acrid smell. SCBA already required — do not rely on odor for hazard assessment at this stage.

Gases Present

HF, HCN, CO at potentially IDLH concentrations. High VOC load. CO₂. Particulate from cell material. In NMC chemistry: cathode oxygen release sustains the reaction without external air supply.

Tactical Action

Large-volume water application externally to the battery pack — goal is COOLING to interrupt cell-to-cell thermal propagation, not conventional flame knockdown. Do NOT breach the battery enclosure. Defensive posture unless immediate life safety requires otherwise. Plan for 10,000–30,000+ gallons. Begin runoff containment — keep contaminated water out of storm drains.

Critical Point — NMC Chemistry

NMC cathode releases oxygen during thermal runaway, making the fire self-sustaining without external air. Conventional suppression logic does not apply. Water volume for cooling is the only available intervention.

Full Fire Involvement

TIC Surface Reading: May saturate — unreliable. Internal pack temperatures can exceed 1,000°F

Visual Signs

Active flames. High heat release rate. Toxic smoke column — do not enter the plume. Possible secondary explosions from cell rupture. Structural damage to vehicle.

Sounds

Intense burning sounds. Possible secondary explosions as cells rupture under pressure.

Gases Present

All off-gas species at high concentrations. Heavy particulate in smoke column. HF and HCN travel in plume — wind direction determines safe zones.

Tactical Action

Defensive posture. Water for exposure protection of surrounding structures and vehicles. If suppression attempted, massive sustained water volume required. Identify wind direction — establish all operations and personnel upwind. Runoff is contaminated — actively contain from storm drain entry. SCBA mandatory. No personnel in plume.

Critical Point

The smoke column from an EV battery fire contains HF and HCN. It is not equivalent to a structural fire smoke column. Wind direction determines which area is the kill zone. Establish positioning before the plume shifts.

Post-Fire / Re-Ignition Watch

TIC Surface Reading: Decreasing — NOT a reliable indicator of internal cell state

Visual Signs

Apparent knockdown. Surface temperatures decreasing on TIC. Residual steam or vapor from water application. No visible flames.

Gases Present

Residual off-gases. Continued low-level venting possible from cells still reacting internally. Atmospheric monitoring must continue.

HV Status

Full high-voltage charge retained internally. 12V disconnect does not de-energize the traction pack. Vehicle is energized regardless of visible fire status. Orange HV cables remain live.

Tactical Action

Cease water application. TIC monitoring every 15–30 minutes minimum. 24–48 hour re-ignition watch minimum. Outdoor storage only — minimum 50 feet from structures and other vehicles. Do NOT release to civilian custody. Do NOT store indoors. Continue atmospheric monitoring. Document runoff pathway and notify environmental authorities.

Critical Point — Re-Ignition

Re-ignition has been documented up to 24+ hours after apparent knockdown. Surface temperature decrease on TIC does NOT indicate internal cell stabilization. Cells deep within the pack may still be in early thermal runaway with no external signature. One hour is not enough. Minimum 24–48 hours.

Battery chemistry directly affects thermal runaway onset temperature, propagation speed, off-gas violence, and the tactical window available for intervention. Knowing the chemistry changes the timeline expectation, not the required PPE. All lithium-ion chemistries produce HF, CO, and HCN during thermal runaway — SCBA is required regardless of chemistry type.

Chemistry Comparison

Source: FAA DOT/FAA/TC-15/59 — TEEX / UL FSRI

Chemistry	Thermal Onset	O₂ Release	Propagation	Common Applications	Tactical Implication
NMC Nickel Manganese Cobalt	~150°C (302°F)	YES — cathode releases oxygen; fire is self-sustaining	Fast — cell-to-cell	Passenger EVs, SUVs, delivery vans — most common in current fleet	Lowest margin for intervention. Conventional suppression logic does not apply.
LFP Lithium Iron Phosphate	~270°C (518°F)	NO — does not release cathode oxygen	Slower — more time to intervene	Commercial EVs, transit buses, some passenger EVs, ESS facilities	Higher onset provides more window. Still produces HF, CO, HCN. Not safe — safer onset only.
NCA Nickel Cobalt Aluminum	~150–170°C (302–338°F)	YES	Fast	High-performance EVs, some older models	Profile similar to NMC. High energy density means more stored energy per unit volume.
LMO Lithium Manganese Oxide	~200°C (392°F)	Partial	Moderate	Older EVs, some hybrids, power tools — less common in current fleet	Intermediate hazard profile. Less common but still present in the response environment.

Universal Rule Across All Chemistries

The fluorine-containing electrolyte salt LiPF₆ (lithium hexafluorophosphate) is present in all four chemistries. HF production during thermal runaway is chemistry-independent. SCBA is required for all lithium-ion battery incidents regardless of chemistry identification. Identification of chemistry affects timeline and propagation expectations — it does not change the required level of respiratory protection.

The off-gas profile of lithium-ion thermal runaway is a multi-species toxic atmosphere. A standard 4-gas meter (CO, LEL, O₂, H₂S) does not detect HF or HCN — the two most immediately tissue-damaging components. Values below are from NIOSH and OSHA. Research concentrations are from TEEX/UL FSRI and FAA testing.

Primary Off-Gas Species

Source: NIOSH Pocket Guide / OSHA / TEEX–UL FSRI / FAA DOT/FAA/TC-15/59

Gas	IDLH (Immediately Dangerous to Life or Health)	OSHA PEL (Permissible Exposure Limit)	Appearance / Odor	Key Health Effects	Detection Note	Research Concentrations
HF Hydrogen Fluoride	30 ppm	3 ppm (ceiling)	Colorless gas. Pungent at high concentrations — may be undetectable by odor at dangerous concentrations	Deep tissue burns (skin, lung, bone). Systemic fluoride toxicity. Cardiac arrhythmia. Symptoms may be delayed — exposure may not be immediately apparent.	Specific electrochemical sensor required. PID has NO response to HF. 4-gas meter does NOT detect HF.	Measured at IDLH levels in both cell-stack and module-scale tests (TEEX/UL FSRI)
HCN Hydrogen Cyanide	50 ppm	10 ppm (ceiling)	Colorless gas. Faint bitter almond odor — not detectable by all individuals; do not rely on odor	Cellular asphyxiation. Rapid incapacitation at high concentrations.	Specific electrochemical sensor required. PID responds poorly. 4-gas meter does NOT detect HCN.	34–200 ppm measured in testing (IDLH: 50 ppm). (TEEX/UL FSRI)
CO Carbon Monoxide	1,200 ppm	50 ppm TWA (Time-Weighted Average)	Colorless, odorless	Tissue hypoxia. CNS (Central Nervous System) depression. Cardiac effects at high concentrations.	Standard 4-gas meter detects CO. Most common instrument coverage.	Up to 25,000 ppm measured in confined environments — 500× OSHA PEL. (TEEX/UL FSRI)
Formaldehyde CH₂O	20 ppm	0.75 ppm TWA STEL (Short-Term Exposure Limit): 2 ppm	Colorless gas. Sharp, pungent odor.	Respiratory irritant. Mucous membrane damage. Carcinogen (IARC — International Agency for Research on Cancer — Group 1).	Specific sensor or colorimetric tube. Not detected by standard 4-gas meter.	Up to 150× OSHA 8-hour limit measured in testing. (TEEX/UL FSRI)
POF₃ Phosphoryl Fluoride	Not established	Not established	Colorless gas. Extremely toxic at low concentrations.	Severe pulmonary damage. Systemic fluoride toxicity. Hydrolysis in moist air produces HF.	Difficult to detect — requires specialized equipment. Absence of alarm does NOT indicate absence of POF₃.	Produced from LiPF₆ decomposition at high temperatures. Present in thermal runaway events.
CO₂ Carbon Dioxide	40,000 ppm	5,000 ppm TWA STEL: 30,000 ppm	Colorless, odorless	Asphyxiation at high concentrations. Displaces oxygen in confined spaces.	Standard 4-gas meter detects O₂ depletion as CO₂ rises.	Significant volumes produced — contributes to O₂ deficiency in confined spaces.

Minimum Monitoring Strategy

Instrument selection must account for the full off-gas profile

Priority	Instrument	What It Covers	What It Misses
1st	Multi-gas meter (CO / LEL / O₂ / H₂S)	CO, flammable atmosphere (LEL), oxygen deficiency	HF, HCN, formaldehyde, POF₃
2nd	Single-gas HCN monitor	Hydrogen cyanide	HF, formaldehyde, POF₃
3rd	HF-specific electrochemical sensor	Hydrogen fluoride	POF₃ (converts to HF in moisture — partial coverage)
4th	PID (photoionization detector)	Total VOC (Volatile Organic Compound) picture — benzene, acetylene, 1,3-butadiene	Zero response to CO, HF, or HCN. PID zero ≠ safe atmosphere.

Water use at EV battery incidents operates in two distinct phases with opposite tactical logic. The decision to apply or stop water application is driven by what the water is doing to the battery, not conventional fire suppression logic. Understanding the mechanism behind each phase is the training objective.

Active Thermal Runaway — Apply Water

Mechanism: Thermal interruption

Purpose

Cooling — remove heat from the battery pack to interrupt cell-to-cell thermal propagation. This is not conventional fire suppression. The goal is to pull temperatures below the propagation threshold, not to knock down visible flames.

Application

External surfaces of the battery pack only. Never breach the battery enclosure. The pack is sealed and internally energized. Directing water into the pack creates electrocution hazard and does not improve cooling.

Volume

Research indicates 10,000–30,000+ gallons for passenger EV battery packs. Transit buses and ESS facilities may require significantly more. Standard vehicle fire flow rates are insufficient. Plan for sustained large-volume supply — tanker relay or hydrant.

What Water Does NOT Do

Water does not neutralize HF, HCN, or CO. Water does not deactivate cells. Water does not eliminate re-ignition risk. It removes heat only — the energy source remains intact.

Runoff

Water that contacts the battery pack and fire debris is contaminated. Even at this phase, begin identifying runoff pathways and prevent entry into storm drains and waterways. The contamination problem begins when water application begins — not after.

Source

ERG 2024 Guide 147 — UL FSRI / TEEX Research

Post-Knockdown — Stop Water Application

Mechanism: Additional water only expands contamination

Rationale

Once active thermal runaway is suppressed, continued water application does not neutralize HF, HCN, or CO already present in the environment. Additional water only increases the volume of contaminated runoff and expands the environmental impact zone without adding tactical value.

Tactical Shift

Cease water application. Shift to TIC monitoring every 15–30 minutes. TIC is now your primary tool. Temperature rising on TIC = potential re-ignition developing internally. Temperature decreasing on TIC does not mean stabilized — internal cells may still be reacting.

Runoff Priority

All runoff from the incident area is contaminated and must be treated as hazardous. Prevent entry into storm drains, gutters, waterways, and soil. Document the runoff pathway. Notify environmental authorities (state EPA (Environmental Protection Agency) or equivalent) — this is a required reporting action in most jurisdictions, not optional.

The Key Distinction

Water during active runaway = necessary and tactically correct. Water after knockdown = increases contamination without benefit. These are two different decisions requiring two different rationales. The error in training is treating water as a single constant throughout the incident.

ERG (Emergency Response Guidebook) 2024, Guide 147 covers lithium-ion and sodium-ion batteries. Distances below are the published starting points. These are minimums, not maximums. Confined spaces require vertical isolation in addition to horizontal distance — ERG distances assume open-air conditions.

ERG 2024 — Guide 147 Isolation & Evacuation Distances

Source: DOT / PHMSA Emergency Response Guidebook 2024

🔥 Fire — Small Battery

Initial Isolation

50 m / 150 ft

All directions

🔥 Fire — Large Battery

Initial Isolation

100 m / 330 ft

All directions

Consider Evacuation

500 m / ⅓ mile

All directions

💧 Spill — Small

Initial Isolation

25 m / 75 ft

All directions

Protective Action Distance

100 m / 330 ft

Downwind

💧 Spill — Large

Initial Isolation

100 m / 330 ft

All directions

Protective Action Distance

500 m / ⅓ mile

Downwind

⚠ Critical Interpretation Notes — Do Not Apply These Distances Without Context

Confined spaces: ERG distances assume open-air conditions. In parking structures, residential garages, or industrial buildings, off-gases concentrate and travel through HVAC (Heating, Ventilation, and Air Conditioning), stairwells, and elevator shafts. Apply the horizontal distance AND add vertical isolation — deny access to floors above and below the event.

Structure walls do not contain hazard: Walls trap off-gases rather than containing them. Confinement makes the hazard worse, not better. The 500m perimeter in a parking structure is physically impossible — the equivalent is floor-by-floor evacuation and access denial.

Re-ignition language (ERG 147): "A lithium ion battery fire may reignite at any point after the initial fire is extinguished, up to weeks later." This is verbatim ERG language — not an approximation.

ⓘ TRAINING DATA ONLY — Specifications vary significantly by model year, trim level, and regional market. Voltage ranges, chemistry, and battery locations are approximate and subject to change. Always consult manufacturer Emergency Response Guides (ERGs) for vehicle-specific disconnect procedures, battery boundary lines, and current specifications. Manufacturer ERGs are available via NFPA AFV (Alternative Fuel Vehicle) Resources and EV FireSafe.

Passenger & Light Duty EVs

Approximate training reference — verify against current manufacturer ERG

Vehicle	Approximate Chemistry	Approx. Pack Size	Approx. Voltage	Battery Location
Tesla Model 3 / Y Standard Range variants	LFP	~60 kWh	~400V	Underfloor — full vehicle width between axles
Tesla Model 3 / Y Long Range / Performance variants	NMC	~75–82 kWh	~400V	Underfloor — full vehicle width between axles
Tesla Model S / X	NCA	~100 kWh	~400V	Underfloor — extended footprint
Chevrolet Bolt EV / EUV	NMC blend	~65 kWh	~350V	Underfloor — T-shaped pack
Ford F-150 Lightning	NMC	~98–131 kWh	~400V	Midship underfloor — integrated into frame
Ford Mustang Mach-E	NMC	~75–91 kWh	~400V	Underfloor
Rivian R1T / R1S	NMC	~135 kWh	~400–800V	Underfloor — large footprint, skateboard platform
Hyundai Ioniq 5 / Kia EV6	NMC	~77 kWh	~800V	Underfloor
Nissan LEAF Older fleet — still in service	LMO/NMC blend	~40–62 kWh	~350V	Underfloor — center tunnel and rear

Commercial, Transit & Energy Storage

Higher voltages — approach with additional caution

Platform Type	Approximate Chemistry	Approximate Pack Size	Approximate Voltage	Battery Location
Electric Transit Bus	NMC or LFP	~300–660 kWh	600–750V	Roof-mounted pods OR underfloor — varies by manufacturer
Electric Delivery Van Various manufacturers	NMC	~100–200 kWh	~400–800V	Underfloor — extended wheelbase
ESS / BESS Facility Battery Energy Storage System	LFP predominantly	Hundreds of kWh (kilowatt-hours) to MWh (megawatt-hours) scale	800–1,500V DC (Direct Current)	Containerized ground units — may be stacked. Floor-level access only.
EV Battery Recycling Facility	Mixed — damaged packs, all chemistries	Variable — degraded packs may retain partial charge	Variable — assume energized until verified otherwise	Rack storage and processing lines — PFAS (Per- and Polyfluoroalkyl Substances) already mobilized from damaged cell material

High-Voltage Safety — Universal Rules

Rule	Explanation
12V disconnect does NOT de-energize the traction pack	Disconnecting the 12V accessory battery opens HV (high-voltage) contactors but cells remain at full charge internally. Stranded energy is retained at full pack voltage regardless of 12V status.
Never cut orange HV cables	Orange color coding indicates HV conductors. Cutting creates arc flash and electrocution hazard. Manufacturer ERGs specify battery boundary lines — cuts must stay outside these boundaries.
Never breach the battery enclosure	The pack is sealed, internally charged, and structurally integral to the vehicle. Opening the enclosure creates arc flash hazard and removes the only barrier between responders and cell-level energy.
ESS voltages exceed passenger EV voltages	Utility-scale ESS systems operate at 800–1,500V DC. Conventional EV high-voltage awareness training does not fully account for ESS voltage levels. Manufacturer guidance required.