DOT Hazmat Class 3: Flammable Liquids
Ignitable vapors, rapid fire spread, and runoff—control ignition and protect exposures.
DOT Hazard Class 3 At a Glance
DOT Hazard Class 3 covers Flammable Liquids. Ignitable vapors, rapid fire spread, and runoff—control ignition and protect exposures. Common examples include Gasoline, Diesel (varies), Ethanol, Paint. Use this guide for placard recognition, hazards, first actions, ERG context, and related UN numbers.
Common Hazards of Class 3 Flammable Liquids
- Vapor ignition and flash fire potential
- Runoff spread and secondary fires
- Toxic combustion products
How to Recognize Class 3 Flammable Liquids
- Liquid spills with strong odor or sheen
- Placard 'Flammable Liquid'
- Vapor accumulation in low areas
First Actions for Class 3 Flammable Liquids Incidents
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
Critical Don'ts for Class 3 Flammable Liquids
- Do not walk through unknown liquids
- Do not create ignition sources (sparks) near vapors
- Do not assume diesel behaves like gasoline
Common Products & Examples — Class 3 Flammable Liquids
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)
More UN numbers discoverable via the Hazmat Hub. Always consult current ERG + SOP/SOG for operations.