Abstract: Foamable silicone compositions, containing (A) at least one organopolysiloxane containing at least two alkenyl groups bonded to silicon per molecule, (B) at least one organopolysiloxane containing at least two hydrogen atoms bonded to silicon per molecule, (C) at least one porogenic agent generating gaseous hydrogen in the presence of component (B), and (D) at least one hydrosilylation catalyst. Foams obtained by curing such foamable silicone compositions have excellent resilience, moderate hardness, good mechanical properties, and flame retardancy, suitable for the sealing of battery pack cases.