Which of the following indicates that a material is flammable in the NFPA 704 system?

• A. Blue
• B. Yellow
• C. Red
• D. White

Answer: (C)

In the NFPA 704 system, the color red is used to indicate flammability. This color-coded system is designed to provide first responders with quick and recognizable information about the hazards associated with materials. The red section of the diamond label indicates the degree of flammability of a substance, with 0 representing materials that do not burn, and 4 indicating materials that can ignite readily under normal conditions. Understanding this color designation is crucial for effective safety protocols in handling and responding to hazardous materials, as it helps firefighters and other emergency personnel to quickly assess the risks and take appropriate action to mitigate hazards.