☣️ DOT Hazmat Classification
Flammable Liquids
Ignitable vapors, rapid fire spread, and runoff—control ignition and protect exposures.
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DOT CLASS 3
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Common Hazards — Class 3
- Vapor ignition and flash fire potential
- Runoff spread and secondary fires
- Toxic combustion products
How to Recognize Class 3
- Liquid spills with strong odor or sheen
- Placard 'Flammable Liquid'
- Vapor accumulation in low areas
First Actions Before Hazmat Team Arrives
Initial priorities for DOT Hazmat Class 3 (Flammable Liquids) incidents. These are general guidelines — always verify with shipping papers, consult the current ERG, and follow your SOP/SOG.
- Eliminate ignition sources and control access
- Approach from upwind; establish isolation
- Protect exposures; consider vapor suppression per SOP
- Request Hazmat if unknown/large release
- Consult ERG and coordinate foam/water strategy
What NOT To Do — Class 3
- Do not walk through unknown liquids
- Do not create ignition sources (sparks) near vapors
- Do not assume diesel behaves like gasoline
Common Examples — Class 3 Flammable Liquids
GasolineDiesel (varies)EthanolPaintAcetone
These are representative examples only. Product-specific hazards vary — always confirm via shipping papers and current ERG.
Common UN Numbers in Class 3 (Flammable Liquids)
UN 1088AcetalUN 1090AcetoneUN 1091Acetone oilsUN 1104Amyl acetatesUN 1105PentanolsUN 1106AmylamineUN 1107Amyl chlorideUN 1108n-AmyleneUN 1109Amyl formatesUN 1110n-Amyl methyl ketoneUN 1111Amyl mercaptanUN 1112Amyl nitrateUN 1113Amyl nitriteUN 1114BenzeneUN 1120Butanols
More UN numbers discoverable via the Hazmat Hub. Always consult current ERG + SOP/SOG for operations.
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FAQ — DOT Hazmat Class 3 (Flammable Liquids)
Many flammable liquids burn from vapor above the liquid surface; vapors can travel to ignition sources.
It depends on product and tactics. Use SOP/SOG and Hazmat guidance; foam may be indicated for many flammable liquids.
Life safety: isolate, control ignition, protect exposures, request Hazmat early.
Sources: DOT/PHMSA hazard class concepts, NFPA 704 overview, and ERG usage principles. This guide does not reproduce ERG guide text — always consult the current ERG for incident-specific protective actions.