# AI advises using a Class A fire extinguisher (water or foam) on a lithium-ion battery fire, or tells someone to smother it with a blanket, ignoring that thermal runaway produces its own oxygen and water can cause hydrogen gas explosions

- **ID:** `safety/lithium-battery-fire-extinguisher`
- **Domain:** safety
- **Category:** physical_safety
- **Error Code:** `BATTERY-FIRE-EXT-001`
- **Verification:** ai_generated
- **Fix Rate:** 82%

## Root Cause

Lithium-ion battery fires involve thermal runaway: the battery generates its own oxygen through decomposition of the cathode, rendering smothering ineffective. Water applied to a burning lithium cell can react with lithium metal to produce hydrogen gas, which ignites explosively. Class D (metal) or Class A extinguishers are inappropriate; only specialized lithium-ion fire extinguishers (e.g., Lith-Ex, aerosol-based suppressants) or copious amounts of water (for large packs) are safe.

## Version Compatibility

| Version | Status | Introduced | Deprecated |
|---------|--------|------------|------------|
| NFPA 855 (Energy Storage Systems) 2023 | active | — | — |
| UL 1642 (Lithium Batteries) 2022 | active | — | — |
| IEC 62133 (Secondary Cells) 2021 | active | — | — |
| DOT 49 CFR 173.185 (Lithium Battery Transport) 2023 | active | — | — |

## Workarounds

1. **For small lithium-ion battery fires (e.g., phone, laptop): use a specialized lithium-ion fire extinguisher (e.g., Lith-Ex, Firechief Lithium-Ion) or an aerosol-based suppressant like 'Elide Fire' or 'Lithium Battery Fire Blanket' that suffocates by blocking oxygen while containing toxic gases. Example: 'Apply Lith-Ex extinguisher at the base of the flames from a safe distance (2m).'** (85% success)
   ```
   For small lithium-ion battery fires (e.g., phone, laptop): use a specialized lithium-ion fire extinguisher (e.g., Lith-Ex, Firechief Lithium-Ion) or an aerosol-based suppressant like 'Elide Fire' or 'Lithium Battery Fire Blanket' that suffocates by blocking oxygen while containing toxic gases. Example: 'Apply Lith-Ex extinguisher at the base of the flames from a safe distance (2m).'
   ```
2. **For large battery packs (EV, e-bike, powerwall): douse with copious amounts of water (at least 10 gallons/40 liters) from a safe distance. Water cools the battery below thermal runaway temperature, even though it may produce hydrogen. Use a hose or fire hydrant, not a bucket. Do not use a portable extinguisher.** (75% success)
   ```
   For large battery packs (EV, e-bike, powerwall): douse with copious amounts of water (at least 10 gallons/40 liters) from a safe distance. Water cools the battery below thermal runaway temperature, even though it may produce hydrogen. Use a hose or fire hydrant, not a bucket. Do not use a portable extinguisher.
   ```
3. **If no specialized extinguisher is available, evacuate the area immediately and call the fire department. Do not attempt to fight the fire yourself. Close doors to contain the fire. Lithium-ion fires can reignite hours later.** (95% success)
   ```
   If no specialized extinguisher is available, evacuate the area immediately and call the fire department. Do not attempt to fight the fire yourself. Close doors to contain the fire. Lithium-ion fires can reignite hours later.
   ```

## Dead Ends

- **** — Using a Class A (water/foam) extinguisher on a small lithium battery fire can cause hydrogen explosions and spread burning electrolyte (70% fail)
- **** — Attempting to smother with a blanket or sand is ineffective because thermal runaway supplies its own oxygen; the fire continues internally (85% fail)
- **** — Using a Class D extinguisher (designed for combustible metals) on a lithium-ion battery is also wrong because the fire involves electrolyte and not just lithium metal; it may not suppress thermal runaway (50% fail)