A biocidal composition comprising: a biocidal agent selected from the group consisting of: 1,3,5-tris (2-hydroxyethyl)-s-triazine, iodopropynylbutylcarbamate, 1,2-benzisothiazolin-3-one, 4,4-dimethyloxazolidine, 7-ethyl bicyclooxazolidine, a combination of 4-(2-nitrobutyl)-morpholine with 4,4'-(2-ethyl-2-nitrotrimethylene) dimorpholine, 2-methyl-4-isothiazolin-3-one, a combination of 5-chloro-2-methyl-4-isothiazolin-3-one with 2-methyl-4-isothiazolin-3-one, 2-bromo-2-nitro-1,3-propanediol, octylisothiazolinone, dichloro-octylisothiazolinone, dibromo-octylisothiazolinone, phenolics such as o-phenylphenol and p-chloro-m-cresol and their corresponding sodium and/or potassium salts, sodium pyrithione, zinc pyrithione, n-butyl benzisothiazolinone, 1-(3-chloroallyl)-3,5,7-triaza-1-azoniaadamantane chloride, chlorothalonil, carbendazim, diiodomethyltolylsulfone, trimethyl-1,3,5-triazine-1,3,5-triethanol, 2,2-dibromo-3-nitrilopropionamide, glutaraldehyde, N,N'-Methylene-bis-morpholine, ethylenedioxy methanol, phenoxyethanol, tetramethylol acetylenediurea, dithiocarbamates, 2,6-Dimethyl-m-dioxan-4-ol acetate, dimethylol-dimethyl-hydantoin, tris(hydroxymethyl)nitromethane, bicyclic oxazolidines, and mixtures of two or more thereof; and a primary amino alcohol compound of the formula: wherein R 1 and R 3 are each independently H, linear or branched alkyl, alkenyl, alkynyl, cycloalkyl, or aryl, or R 1, R 3 and the carbon to which they are attached form a cycloalkyl ring, R 2 is C 1 -C 2 alkyl and R 4 is H or C 1 -C 2 alkyl, provided that R 2 and R 4 together contain 2 or fewer carbon atoms; and R 5 is absent or is C 1 -C 10 alkylene, arylene, -arylene-alkylene-, or -alkylene-arylene-; wherein alkyl, cycloalkyl, alkylene, aryl, and arylene are optionally substituted with alkyl or phenyl, and wherein the compound of formula contains at least 6 carbon atoms and comprises no more than 12 carbon atoms. a biocidal agent selected from the group consisting of: 1,3,5-tris (2-hydroxyethyl)-s-triazine, iodopropynylbutylcarbamate, 1,2-benzisothiazolin-3-one, 4,4-dimethyloxazolidine, 7-ethyl bicyclooxazolidine, a combination of 4-(2-nitrobutyl)-morpholine with 4,4'-(2-ethyl-2-nitrotrimethylene) dimorpholine, 2-methyl-4-isothiazolin-3-one, a combination of 5-chloro-2-methyl-4-isothiazolin-3-one with 2-methyl-4-isothiazolin-3-one, 2-bromo-2-nitro-1,3-propanediol, octylisothiazolinone, dichloro-octylisothiazolinone, dibromo-octylisothiazolinone, phenolics such as o-phenylphenol and p-chloro-m-cresol and their corresponding sodium and/or potassium salts, sodium pyrithione, zinc pyrithione, n-butyl benzisothiazolinone, 1-(3-chloroallyl)-3,5,7-triaza-1-azoniaadamantane chloride, chlorothalonil, carbendazim, diiodomethyltolylsulfone, trimethyl-1,3,5-triazine-1,3,5-triethanol, 2,2-dibromo-3-nitrilopropionamide, glutaraldehyde, N,N'-Methylene-bis-morpholine, ethylenedioxy methanol, phenoxyethanol, tetramethylol acetylenediurea, dithiocarbamates, 2,6-Dimethyl-m-dioxan-4-ol acetate, dimethylol-dimethyl-hydantoin, tris(hydroxymethyl)nitromethane, bicyclic oxazolidines, and mixtures of two or more thereof; and a primary amino alcohol compound of the formula: wherein R 1 and R 3 are each independently H, linear or branched alkyl, alkenyl, alkynyl, cycloalkyl, or aryl, or R 1, R 3 and the carbon to which they are attached form a cycloalkyl ring, R 2 is C 1 -C 2 alkyl and R 4 is H or C 1 -C 2 alkyl, provided that R 2 and R 4 together contain 2 or fewer carbon atoms; and R 5 is absent or is C 1 -C 10 alkylene, arylene, -arylene-alkylene-, or -alkylene-arylene-; wherein alkyl, cycloalkyl, alkylene, aryl, and arylene are optionally substituted with alkyl or phenyl, R 1 and R 3 are each independently H, linear or branched alkyl, alkenyl, alkynyl, cycloalkyl, or aryl, or R 1, R 3 and the carbon to which they are attached form a cycloalkyl ring, R 2 is C 1 -C 2 alkyl and R 4 is H or C 1 -C 2 alkyl, provided that R 2 and R 4 together contain 2 or fewer carbon atoms; and R 5 is absent or is C 1 -C 10 alkylene, arylene, -arylene-alkylene-, or -alkylene-arylene-; wherein alkyl, cycloalkyl, alkylene, aryl, and arylene are optionally substituted with alkyl or phenyl,