Why should straight stream be avoided on pool fires?

Why should straight stream be avoided on pool fires?

• A. It can churn/splash fuel, spread fire, and disturb foam blankets causing flashback
• B. It improves cooling only
• C. It increases foam blanket stability
• D. It reduces fire spread

Answer: (B)

Straight stream delivers a concentrated, high-velocity jet that concentrates energy in a small area. On a pool fire, that impact can churn and splash burning fuel, spreading flames to nearby surfaces and increasing the risk of ignition elsewhere. It also tends to disrupt and wash away the foam blanket that’s used to blanket the surface and absorb heat, which can compromise cooling and allow vapors to reignite or flash back toward the nozzle. The preferred approach is a fog or wide-angle spray that cools the surface more evenly, blankets the fuel, and minimizes disturbance to the fuel layer. By avoiding the straight stream, you reduce fuel movement, protect the foam blanket, and lower the chance of re-ignition.

Straight stream delivers a concentrated, high-velocity jet that concentrates energy in a small area. On a pool fire, that impact can churn and splash burning fuel, spreading flames to nearby surfaces and increasing the risk of ignition elsewhere. It also tends to disrupt and wash away the foam blanket that’s used to blanket the surface and absorb heat, which can compromise cooling and allow vapors to reignite or flash back toward the nozzle. The preferred approach is a fog or wide-angle spray that cools the surface more evenly, blankets the fuel, and minimizes disturbance to the fuel layer. By avoiding the straight stream, you reduce fuel movement, protect the foam blanket, and lower the chance of re-ignition.