AI tells someone to use a water extinguisher on an electrical fire involving live equipment, or to use a CO2 extinguisher on a metal fire
ID: safety/electrical-fire-extinguisher
Version Compatibility
| Version | Status | Introduced | Deprecated | Notes |
|---|---|---|---|---|
| NFPA 10 (Standard for Portable Fire Extinguishers) 2023 Edition | active | — | — | — |
| OSHA 29 CFR 1910.157 | active | — | — | — |
| BS EN 3 (European Standard for Portable Fire Extinguishers) | active | — | — | — |
Root Cause
Fire extinguisher classes: Class A (ordinary combustibles), B (flammable liquids), C (electrical), D (combustible metals), K (cooking oils). Water extinguishers (Class A) conduct electricity, causing electrocution if used on live equipment. CO2 extinguishers (Class B/C) are ineffective on metal fires (Class D) because metals burn at high temperatures and CO2 does not cool them; they may react with some metals (e.g., magnesium). AI may confuse extinguisher ratings or assume 'all-purpose' means safe for all fires. NFPA 10 and OSHA 29 CFR 1910.157 mandate correct extinguisher selection.
generic中文
灭火器类别：A类（普通可燃物）、B类（易燃液体）、C类（电气）、D类（可燃金属）、K类（食用油）。水灭火器（A类）导电，用于带电设备会导致触电。二氧化碳灭火器（B/C类）对金属火灾（D类）无效，因为金属在高温下燃烧，二氧化碳无法冷却；某些金属（如镁）可能与二氧化碳反应。AI可能混淆灭火器等级或认为'通用型'适用于所有火灾。NFPA 10和OSHA 29 CFR 1910.157要求正确选择灭火器。
Official Documentation
https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.157Workarounds
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95% success For electrical fires (Class C): use a CO2 or dry chemical (ABC) extinguisher. Ensure the extinguisher is rated for Class C (look for a blue circle with 'C'). Never use water. If the fire is small and the device is unplugged, a fire blanket can smother it. Example: 'Pull the pin, aim at the base of the fire, squeeze the handle, sweep side to side.'
For electrical fires (Class C): use a CO2 or dry chemical (ABC) extinguisher. Ensure the extinguisher is rated for Class C (look for a blue circle with 'C'). Never use water. If the fire is small and the device is unplugged, a fire blanket can smother it. Example: 'Pull the pin, aim at the base of the fire, squeeze the handle, sweep side to side.'
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85% success For metal fires (Class D): use a Class D extinguisher (e.g., Met-L-X or Lith-X). If unavailable, smother with dry sand or sodium chloride (table salt) in large quantities. Do not use water, CO2, or ABC dry chemical. For lithium-ion battery fires, use a lithium fire blanket or Class D extinguisher; if outdoors, let it burn in a safe area.
For metal fires (Class D): use a Class D extinguisher (e.g., Met-L-X or Lith-X). If unavailable, smother with dry sand or sodium chloride (table salt) in large quantities. Do not use water, CO2, or ABC dry chemical. For lithium-ion battery fires, use a lithium fire blanket or Class D extinguisher; if outdoors, let it burn in a safe area.
中文步骤
For electrical fires (Class C): use a CO2 or dry chemical (ABC) extinguisher. Ensure the extinguisher is rated for Class C (look for a blue circle with 'C'). Never use water. If the fire is small and the device is unplugged, a fire blanket can smother it. Example: 'Pull the pin, aim at the base of the fire, squeeze the handle, sweep side to side.'
For metal fires (Class D): use a Class D extinguisher (e.g., Met-L-X or Lith-X). If unavailable, smother with dry sand or sodium chloride (table salt) in large quantities. Do not use water, CO2, or ABC dry chemical. For lithium-ion battery fires, use a lithium fire blanket or Class D extinguisher; if outdoors, let it burn in a safe area.
Dead Ends
Common approaches that don't work:
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80% fail
ABC dry chemical (usually monoammonium phosphate) is ineffective on Class D metal fires; it can react with some metals (e.g., sodium) and may not smother the fire. Class D extinguishers use specialized agents like sodium chloride or copper powder.
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60% fail
Even unplugged, capacitors in electronics can retain lethal charge (e.g., microwave ovens, power supplies). Water conducts across residual charge, causing electrocution. Also, water damages equipment.
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70% fail
CO2 can extinguish the flame but does not cool the battery sufficiently; thermal runaway continues and the battery can reignite. Use a Class D extinguisher or lithium-specific fire blanket.