What transportation hazard class placard indicates flammable liquids?

Under theDepartment of Transportation (DOT)hazardous materials regulations (49 CFR Part 172),Flammable Liquidsare designated asClass 3. A flammable liquid is defined as any 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 at or above its flash point in a bulk package. The Class 3 placard is identifiable by itsRed backgroundwith a white flame symbol at the top and the number "3" at the bottom.

The other classes mentioned are:

Class 2 (Option A):Refers toGases, which are subdivided into 2.1 (Flammable Gas), 2.2 (Non-flammable Gas), and 2.3 (Poisonous Gas).

Class 4 (Option C):Refers toFlammable Solids, including spontaneously combustible materials and dangerous-when-wet materials.

For aCertified Emergency and Disaster Professional (CEDP), the DOT Class 3 placard is a "High-Priority" indicator during a transportation accident. Whether on a tanker truck, a railcar, or a shipping container, the "Red 3" placard signals an immediate risk of fire and potential explosion (BLEVE) if the container is exposed to heat. Responders use theEmergency Response Guidebook (ERG), specificallyGuide 128, to determine the initial isolation distance (typically 150 feet) and the appropriate firefighting foam for a Class 3 spill. This standardized classification system is the foundation of global hazardous materials transportation safety, ensuring that the "hazard communication" is clear and consistent across all modes of transport.1