Abstract: Foam carrying a decontaminating/oxidizing agent is produced by introducing air under pressure into a pair of tanks (10, 11) carrying a foam forming solution and a solution of the agent. The tanks (10, 11) are connected to an air passage (2) through a manifold (1) for introducing the foam solution and then the agent solution into the air passage (2) to produce foam bubbles coated with agent for discharge under pressure through a hose (19) connected to said air passage (2). Alternatively, the two solutions are mixed in a single tank (22) connected to a source of air (23) under pressure, and the resulting mixture is discharged through a hose (37) and a foam-forming nozzle (40) at the discharge end of the hose (37).