A biliquid foam includes from 10% to 98% by weight of a non-polar liquid other than a fuel and from 2 to 88% by weight of a continuous phase polar liquid comprising a C1-C4 alcohol, a liquid polyethylene glycol, ethylene glycol or propylene glycol, or mixtures thereof, in an amount of at least 65% by weight, relative to the weight of the continuous phase, wherein the biliquid foam is stabilized with an amount of from 0.05% to 2% by weight based on the total formulation of a surfactant which is selected from castor oil/poly(alkylene glycol) adducts containing from 20 to 50 alkoxy groups, a C8-C24 fatty acid or hydrogenated castor oil/poly(alkylene glycol) adducts containing from 20 to 60 alkoxy groups, or mixtures thereof.
