Water on a fire involving flammable liquids such as oil will do what?

Water on a fire involving flammable liquids such as oil will do what?

• A. Decrease
• B. Increase
• C. Extinguish
• D. Stop

Answer: (B)

Flammable liquid fires react differently to water than water-based fires. Oil and other hydrocarbons sit on top of water because they’re less dense, so when you pour water onto a burning oil surface the water can sink beneath the oil layer and instantly turn to steam. That rapid steam production expands dramatically and can force burning oil droplets to spit and spread the flame to wider areas, increasing the fire’s size and intensity. Water also doesn’t mix with oil, so it doesn’t provide effective cooling at the fuel surface or smother the flame, since the vapor above the liquid keeps feeding combustion. In short, applying water to an oil fire tends to make the fire worse rather than better. Use foam, dry chemical, CO2, or other appropriate Class B suppression methods to blanket or separate the fuel.

Flammable liquid fires react differently to water than water-based fires. Oil and other hydrocarbons sit on top of water because they’re less dense, so when you pour water onto a burning oil surface the water can sink beneath the oil layer and instantly turn to steam. That rapid steam production expands dramatically and can force burning oil droplets to spit and spread the flame to wider areas, increasing the fire’s size and intensity. Water also doesn’t mix with oil, so it doesn’t provide effective cooling at the fuel surface or smother the flame, since the vapor above the liquid keeps feeding combustion. In short, applying water to an oil fire tends to make the fire worse rather than better. Use foam, dry chemical, CO2, or other appropriate Class B suppression methods to blanket or separate the fuel.