A composition having biocidal properties is disclosed. The composition includes a first biocide, optionally a second biocide, and a biocide enhancing agent. The first biocide may comprise an isothiazolin. The second biocide may comprise a pyrithione. The biocide enhancing agent may comprise an amine, an amine salt, an amine oxide, or mixtures thereof. The amine compound may have a carbon chain length of at least six carbon atoms, such as at least eight carbon atoms.
