A kit for the production of an antimicrobial foam includes: a) a liquid composition which includes a1)one or more bispyridinium alkane and a2)one or more surfactants selected from non-ionic surfactants, amphoteric surfactants and cation-active surfactants, wherein the composition is formulated so that a foam can be produced therefrom, and b) a device for producing the foam from the composition. By using the bispyridinium alkanes the foam stability of liquid and surfactant-containing compositions is increased.