Silicone composition for elastomer foam

An organopolysiloxane composition X that is a precursor of a silicone foam M, the composition X comprising:

• a. from about 40% to about 80% by weight of at least one organopolysiloxane A exhibiting, per molecule, at least two C2-C6 alkenyl groups bonded to the silicon,
• b. from about 1% to about 20% of at least one organopolysiloxane B exhibiting, per molecule, at least two SiH units,
• c. from about 2 to about 400 ppm by weight a catalytically effective amount of at least one hydrosilylation platinum catalyst C,
• d. from about 0.3% to about 2.5% by weight of at least one porogenic agent D, which is water or an aqueous emulsion,
• e. at least about 3% by weight, with respect to the total amount of the composition X, of at least one inorganic filler E, which is a fumed silica, the specific surface of which is from about 100 m2/g to about 300 m2/g,
• f. at least 6% by weight, with respect to the total amount of the composition X, of at least one inorganic filler F, which is a ground quartz, and
• g. from about 0.4% to about 5% by weight of at least one heat-resistance additive J,
• wherein the ratio by weight of the quartz F to the fumed silica E is from about 1.5 to about 4;
• and
• wherein the silicone foam M obtained by crosslinking and/or curing of the organopolysiloxane composition X has a limiting oxygen index of more than 33.