DOT Hazard Class

Class 3

Flammable and Combustible Liquids

49 CFR §173.120

Placard: Red placard with flame symbol

ERG entries

593

Divisions

—

Packing groups

I · II · III

Compat groups

—

Definition

A liquid having a flash point of not more than 60 °C (140 °F), or any material in a liquid phase with a flash point at or above 37.8 °C (100 °F) that is intentionally heated and offered for transportation or transported at or above its flash point in a bulk packaging (elevated-temperature flammable).

Primary hazards

Highly flammable — easily ignited by heat, sparks, or flames
Vapors may form explosive mixtures with air
Vapors may travel to source of ignition and flash back
Runoff to sewer may create fire or explosion hazard
Container may explode in heat of fire

Public safety response

Isolate spill or leak area for at least 50 m (150 ft) for liquids. Eliminate all ignition sources (no smoking, flares, sparks, or flames). Stay upwind. Ventilate closed spaces before entering.

Common materials in this class

Gasoline, diesel fuel, ethanol, methanol, acetone, toluene, benzene, xylene, ethers, ketones, most paints and adhesives.

UN1090Acetone UN1170Ethanol UN1203Gasoline UN1219Isopropanol UN1993Flammable liquid, n.o.s.

Packing groups

I: Great danger — initial boiling point ≤ 35 °C (95 °F)
II: Medium danger — flash point < 23 °C (73 °F) and initial boiling point > 35 °C
III: Minor danger — flash point ≥ 23 °C and ≤ 60 °C (140 °F)

Special provisions / notes

Combustible liquid (flash point > 60 °C and ≤ 93 °C) is a domestic-US-only classification when not otherwise regulated. Elevated-temperature material carries the HOT marking (49 CFR §172.325).

Definition

Primary hazards

Highly flammable — easily ignited by heat, sparks, or flames
Vapors may form explosive mixtures with air
Vapors may travel to source of ignition and flash back
Runoff to sewer may create fire or explosion hazard
Container may explode in heat of fire

Public safety response

Isolate spill or leak area for at least 50 m (150 ft) for liquids. Eliminate all ignition sources (no smoking, flares, sparks, or flames). Stay upwind. Ventilate closed spaces before entering.

Common materials in this class

Gasoline, diesel fuel, ethanol, methanol, acetone, toluene, benzene, xylene, ethers, ketones, most paints and adhesives.

UN1090Acetone UN1170Ethanol UN1203Gasoline UN1219Isopropanol UN1993Flammable liquid, n.o.s.

Packing groups

I: Great danger — initial boiling point ≤ 35 °C (95 °F)
II: Medium danger — flash point < 23 °C (73 °F) and initial boiling point > 35 °C
III: Minor danger — flash point ≥ 23 °C and ≤ 60 °C (140 °F)

Special provisions / notes

Combustible liquid (flash point > 60 °C and ≤ 93 °C) is a domestic-US-only classification when not otherwise regulated. Elevated-temperature material carries the HOT marking (49 CFR §172.325).