Researchers design formula to put out underground fires more effectively

When combined with water, the fire suppressant cuts the amount of time and water needed to extinguish peat fires by 40 per cent

Spotted: Researchers at Imperial College London have designed a formula for tackling “zombie fires” in peatlands, which can burn through carbon-rich organic matter underground and re-trigger wildfires again, even after the danger appears to have passed.

Part of the reason zombie fires are so difficult to put out is because when only the surface tension of water is used, it doesn’t run evenly through the soil. This leaves smouldering hotspots. 

The team experimented in the laboratory with adding a biodegradable wetting agent made from plant matter to water, finding that the suppressant lowered the surface tension of the liquid and enabled it to seep into the soil in a more uniform way.

The research, which was published in the International Journal of Wildland Fire, revealed that a one per cent concentration reduced the average time it took to suppress the fire by 39 per cent, while a five per cent concentration reduced it by 26 per cent.

The scientists concluded that the agent worked by encapsulating the fire and lowering its temperature, allowing the fire to be suppressed using between a third and a half of the usual amount of water. 

The next step is for the team to build on their findings by conducting further experiments on controlled peat fires out in the field.

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