How does lower surface tension affect flame spread across a surface?

Lower surface tension affects flame spread across a surface by allowing for faster flame spread. When surface tension is lower, the liquid fuel can spread out more easily across the surface. This increased ability to flow and cover a larger area creates a more extensive surface for combustion to occur, enhancing the flame's ability to ignite and propagate more rapidly.

In the context of fire behavior, when fuels with lower surface tension are present, flames can access more fuel, allowing the fire to grow and spread. This characteristic is crucial for understanding how different materials will behave in a fire scenario. In contrast, higher surface tension can inhibit the spread of liquid fuels, limiting the area that can catch fire and slowing down the overall flame spread.