What does the yellow quadrant in NFPA 704 represent?

• A. Health risk assessment of the material
• B. Flammability potential of the chemical
• C. Instability/reactivity of the material
• D. Special hazards associated with the substance

Answer: (C)

The yellow quadrant in the NFPA 704 labeling system specifically indicates the instability or reactivity of a material. This quadrant informs responders about the potential for a chemical to undergo hazardous reactions under certain conditions, such as the presence of heat, pressure, or other reactive substances. A higher number in the yellow quadrant signifies increased risk—indicating that the material may explode, polymerize, or decompose under certain conditions, which is crucial information for safely managing a hazardous materials incident. Understanding this aspect of the NFPA system helps emergency responders assess the risks and determine the appropriate action to take during a response to hazardous materials.