An antifoam powder comprising 10 to 35 % by weight of a modified amino silicone antifoam fluid of the formula X R 2 Si(OSi A R) n (OSiR 2) m OSiR 2 X where A is an amino radical of the formula -R 1 -[NR 2 -R 3 -] x NR 2 2 or an amino radical of the formula selected from the group - (CH 2) 3 NHC 6 H 11, - (CH 2) 3 NH(CH 2) 2 NHC 6 H 11, - (CH(CH 3)CH 2 CH 2)NHC 6 H 11, - (CH(CH 3)CH 2 CH 2)NH(CH 2)NHC 6 H 11, - (CH 2)NHC 6 H 11 and - (CH 2)NH(CH 2) 2 NHC 6 H 11, or the protonated amino forms of the amino radical A and/or acylated amino forms of the above said amino radicals, X is R or a polyoxyalkylene group G of the formula -R 4 -(O-R 5) y -O-R 6 R is a monovalent hydrocarbon radical having from 1 to 18 carbon atoms, R 1 is a C 1- C 10 -alkylene radical, preferably a radical of the formula -CH 2 CH 2 CH 2 -, R 2 is a hydrogen atom or a C 1 -C 4 -alkyl radical, preferably a hydrogen atom, R 3 is a C 1 -C 10 -alkylene radical, preferably a radical of the formula -CH 2 CH 2 -, R 4 is a C 1 -C 10 -alkylene radical, preferably a radical of the formula -CH 2 CH 2 CH 2 -, R 5 is a C 1 -C 4 -alkylene radical, preferably a radical of the formula -CH 2 CH 2 - or -CH 2 CH 2 (CH 3))- or mixtures of them, R 6 is a hydrogen atom or an C 1 -C 4 -alkyl radical, preferably a hydrogen atom or a methyl radical, more preferably a hydrogen atom, n is an integer from 1 to 6, preferably from 1 to 3, m is an integer from 1 to 200, preferably from 1 to 80, x is 0 or 1 and y is an integer from 5 to 20, preferably from 5 to 12, with the provision that on average from 30 to 60 mol%, preferably 50 mol%, of radicals X are polyoxyalkylene groups G; and 65 to 90 % by weight of a carrier filler selected from the group comprising of sodium carbonate, sodium sulphate, aluminium silicate, potassium carbonate, potassium sulphate, sodium bicarbonate, potassium bicarbonate and zeolite. 10 to 35 % by weight of a modified amino silicone antifoam fluid of the formula X R 2 Si(OSi A R) n (OSiR 2) m OSiR 2 X where A is an amino radical of the formula -R 1 -[NR 2 -R 3 -] x NR 2 2 or an amino radical of the formula selected from the group - (CH 2) 3 NHC 6 H 11, - (CH 2) 3 NH(CH 2) 2 NHC 6 H 11, - (CH(CH 3)CH 2 CH 2)NHC 6 H 11, - (CH(CH 3)CH 2 CH 2)NH(CH 2)NHC 6 H 11, - (CH 2)NHC 6 H 11 and - (CH 2)NH(CH 2) 2 NHC 6 H 11, or the protonated amino forms of the amino radical A and/or acylated amino forms of the above said amino radicals, X is R or a polyoxyalkylene group G of the formula -R 4 -(O-R 5) y -O-R 6 R is a monovalent hydrocarbon radical having from 1 to 18 carbon atoms, R 1 is a C 1- C 10 -alkylene radical, preferably a radical of the formula -CH 2 CH 2 CH 2 -, R 2 is a hydrogen atom or a C 1 -C 4 -alkyl radical, preferably a hydrogen atom, R 3 is a C 1 -C 10 -alkylene radical, preferably a radical of the formula -CH 2 CH 2 -, R 4 is a C 1 -C 10 -alkylene radical, preferably a radical of the formula -CH 2 CH 2 CH 2 -, R 5 is a C 1 -C 4 -alkylene radical, preferably a radical of the formula -CH 2 CH 2 - or -CH 2 CH 2 (CH 3))- or mixtures of them, R 6 is a hydrogen atom or an C 1 -C 4 -alkyl radical, preferably a hydrogen atom or a methyl radical, more preferably a hydrogen atom, n is an integer from 1 to 6, preferably from 1 to 3, m is an integer from 1 to 200, preferably from 1 to 80, x is 0 or 1 and y is an integer from 5 to 20, preferably from 5 to 12, with the provision that on average from 30 to 60 mol%, preferably 50 mol%, of radicals X are polyoxyalkylene groups G; and A is an amino radical of the formula -R 1 -[NR 2 -R 3 -] x NR 2 2 or an amino radical of the formula selected from the group - (CH 2) 3 NHC 6 H 11, - (CH 2) 3 NH(CH 2) 2 NHC 6 H 11, - (CH(CH 3)CH 2 CH 2)NHC 6 H 11, - (CH(CH 3)CH 2 CH 2)NH(CH 2)NHC 6 H 11, - (CH 2)NHC 6 H 11 and - (CH 2)NH(CH 2) 2 NHC 6 H 11, or the protonated amino forms of the amino radical A and/or acylated amino forms of the above said amino radicals, X is R or a polyoxyalkylene group G of the formula -R 4 -(O-R 5) y -O-R 6 R is a monovalent hydrocarbon radical having from 1 to 18 carbon atoms, R 1 is a C 1- C 10 -alkylene radical, preferably a radical of the formula -CH 2 CH 2 CH 2 -, R 2 is a hydrogen atom or a C 1 -C 4 -alkyl radical, preferably a hydrogen atom, R 3 is a C 1 -C 10 -alkylene radical, preferably a radical of the formula -CH 2 CH 2 -, R 4 is a C 1 -C 10 -alkylene radical, preferably a radical of the formula -CH 2 CH 2 CH 2 -, R 5 is a C 1 -C 4 -alkylene radical, preferably a radical of the formula -CH 2 CH 2 - or -CH 2 CH 2 (CH 3))- or mixtures of them, R 6 is a hydrogen atom or an C 1 -C 4 -alkyl radical, preferably a hydrogen atom or a methyl radical, more preferably a hydrogen atom, n is an integer from 1 to 6, preferably from 1 to 3, m is an integer from 1 to 200, preferably from 1 to 80, x is 0 or 1 and y is an integer from 5 to 20, preferably from 5 to 12, 65 to 90 % by weight of a carrier filler selected from the group comprising of sodium carbonate, sodium sulphate, aluminium silicate, potassium carbonate, potassium sulphate, sodium bicarbonate, potassium bicarbonate and zeolite.