1. Stable at low temperatures, a biocidal composition comprising: a compound of formula I: wherein R is hydrogen, methyl or ethyl； x is 1 or 2； y is 0 or 1； and the sum of x and y is 2； and aromatic alcohol. 2. Stable at low temperatures, the biocidal composition according to claim 1, where R is ethyl. Stable at low temperatures, the biocidal composition according to claim 1, where y is 1.4. Stable at low temperatures, the biocidal composition according to claim 1, where y is 0.5. The stable low temperature biocidal composition according to claim 1, wherein the compound of formula (I) is selected from: N- (2-nitroethyl) morpholine, N- (2-nitropropyl) morpholine, N- (2-nitrobutyl) morpholine, 2-nitro -1,3-dimorpholinopropane, 2-methyl-2-nitro-1,3-dimorpholinopropane, 2-ethyl-2-nitro-1,3-dimorpholinopropane and a mixture of two or more of them. 6. Stable at low temperatures, the biocidal composition according to claim 1, wherein the compound of formula (I) comprises a mixture of N- (2-nitrobutyl) morpholine and 2-ethyl-2-nitro-1,3-dimorpholinopropane. 7. The biocidal composition stable at low temperatures according to claim 1, wherein the aromatic alcohol is selected from phenoxyethanol, benzyl alcohol and aromatic glycol ethers. Stable at low temperatures, the biocidal composition according to claim 1, wherein the compound of formula (I) comprises a mixture of N- (2-nitrobutyl) morpholine and 2-ethyl-2-nitro-1,3-dimorpholinopropane, and the aromatic alcohol is phenoxyethanol. A mixture containing liquid fuel and a biocidal composition according to claim 1.10. A method for ensuring the stability of a matrix susceptible to growth of microorganisms, comprising introducing into the matrix an effective amount of a biocidal composition according to claim 1.1. Стабильная при низких температурах биоцидная композиция, содержащая:соединение формулы I:где R представляет собой водород, метил или этил； x равен 1 или 2； y равен 0 или 1； и сумма x и y равна 2；и ароматический спирт.
