Fire Safety Science Digital Archive

The breakdown and subsequent drainage of a foam layer on the surface of petrol has been measured for a range of petrol temperatures, using different types of foam compound. In the experiments described, the liquid resulting from the breakdown of the foam was collected after it had drained, and a "petrol resistance index", defined as the time in which 25 per cent of the liquid content of the foam could be collected, was calculated. This index was found to vary greatly with the temperature of the petrol and this type of foaming agent employed.