Which of the following is NOT listed as a factor in smoke reading?

• A. Volume velocity
• B. Density
• C. Color
• D. Mass of water

Answer: (D)

Smoke reading relies on observable indicators of how a fire behaves: how much smoke is produced and how it moves, how thick the smoke is, and what its color shows. The volume and velocity tell you the rate and direction of the smoke flow, which helps judge fire growth and ventilation needs. Density describes how opaque the smoke is, indicating the amount of particulates and heat involved, which affects visibility and potential hazards. Color gives clues about the fuels and combustion conditions—different colors point to different temperatures and products of burning. Mass of water isn’t a factor in smoke reading because it doesn’t describe the smoke’s behavior or appearance; water relates more to suppression effects (steam) than to the indicators used to read smoke.