The number ___ would be shown in the Flammability quadrant of the NFPA 704 system for a material that must be moderately heated before ignition can occur and on which water spray may be used to extinguish a fire.

The number ___ would be shown in the Flammability quadrant of the NFPA 704 system for a material that must be moderately heated before ignition can occur and on which water spray may be used to extinguish a fire.

• A. 0
• B. 1
• C. 2
• D. 3

Answer: (C)

NFPA 704 uses a 0–4 flammability scale in the red quadrant to show how easily a material can ignite. A rating of 2 indicates a moderate level of flammability: the material isn’t easily ignited at room temperature, but it will ignite with some heating. The fact that water spray may be used to extinguish a fire involving this material means cooling the heat source and the container is effective, helping to suppress vapors and prevent further ignition. So, a moderate flammability rating best fits the description, which is why the number shown would be 2.

NFPA 704 uses a 0–4 flammability scale in the red quadrant to show how easily a material can ignite. A rating of 2 indicates a moderate level of flammability: the material isn’t easily ignited at room temperature, but it will ignite with some heating. The fact that water spray may be used to extinguish a fire involving this material means cooling the heat source and the container is effective, helping to suppress vapors and prevent further ignition. So, a moderate flammability rating best fits the description, which is why the number shown would be 2.