SYNERGISTIC ANTIMICROBIAL COMBINATIONS CONTAINING QUATERNARY AMMONIUM BIOCIDE

1 . A composition having biocidal properties comprising:

a first biocide comprising a salt of a quaternary ammonium cation; and

a second biocide selected so as to synergistically operate in conjunction with the first biocide in order to kill or inhibit growth of a microorganism, the second biocide comprising an alkyl quaternary ammonium halide, a benzyl ammonium halide, a quaternary ammonium propionate, a tertiary amine, or a pyrithione, and wherein the second biocide is present in relation to the first biocide such that the ability of both biocides to kill or inhibit the growth of the microorganism is greater than if only one of the biocides were present at the same concentration of both biocides together.

2 . A composition as defined in claim 1 , wherein the first biocide comprises a carbonate/bicarbonate salt of a quaternary ammonium cation.

3 . A composition as defined in claim 1 , wherein the first biocide has a fractional inhibitory concentration in the composition against the microorganism and the second biocide also has a fractional inhibitory concentration in the composition against the microorganism and wherein the sum of the fractional inhibitory concentration of the first biocide and the fractional inhibitory concentration of the second biocide is less than 1.

4 . A composition as defined in claim 1 , wherein the first biocide has a fractional inhibitory concentration in the composition against the microorganism and the second biocide also has a fractional inhibitory concentration in the composition against the microorganism and wherein the sum of the fractional inhibitory concentration of the first biocide and the fractional inhibitory concentration of the second biocide is less than about 0.8.

5 . A composition as defined in claim 1 , wherein the microorganism comprises a gram positive bacteria.

6 . A composition as defined in claim 1 , wherein the microorganism comprises a gram negative bacteria.

7 . A composition as defined in claim 1 , wherein the microorganism comprises a fungi, a virus, a yeast, a spore, or a mycobacteria.

8 . A composition as defined in claim 1 , wherein the salt of a quaternary ammonium cation comprises at least one di C 8 to C 12 alkyl ammonium carbonate/bicarbonate.

9 . A composition as defined in claim 1 , wherein the salt of a quaternary ammonium cation comprises didecyl dimethyl ammonium carbonate/bicarbonate.

10 . A composition as defined in claim 1 wherein the second biocide comprises the quaternary ammonium halide, the quaternary ammonium halide comprising a di C 8 to C 12 alkyl dimethyl ammonium chloride, such as didecyl dimethyl ammonium chloride.

11 . A composition as defined in claim 1 , wherein the second biocide comprises the benzyl ammonium halide, the benzyl ammonium halide comprising a benzyl C 12 to C 18 alkyl dimethyl ammonium chloride.

12 . A composition as defined in claim 1 , Wherein the second biocide comprises the quaternary ammonium propionate, the quaternary ammonium propionate comprising N,N-didecyl-N-methyl-poly(oxyethyl) ammonium propionate.

13 . A composition as defined in claim 1 , wherein the second biocide comprises the tertiary amine, the tertiary amine comprising N-3-aminopropyl-N-dodecylpropane-1-3-diamine.

14 . A composition as defined in claim 1 , wherein the second biocide comprises the pyrithione, the pyrithione comprising a pyrithione salt, such as sodium pyrithione.

15 . A composition as defined in claim 1 , wherein the first biocide and the second biocide are present in the composition at a weight ratio of from about 1:5 to about 5:1.

16 . A composition as defined in claim 1 , wherein the microorganism comprises Staphylococcus aureus, Streptococcus pneumoniae, Pseudomonas aeruginosa, Serratia marcescens, Salmonella enteritidis, Neisseria gonorrhoeae, Escherichia coli, Enterococcus hirae, Acinetobacter baumannii, Listeria monocytogenes, Enterobacter gergoviae, Klebsiella pneumoniae, Burholderia cepacia, Pseudomonas putida, Kocuria rhizophila, Candida albicans, Saccharomyces cerevisiae, Aspergillus brasiliensis, Penicillium funiculosum, Eupenicillium levitum, Bacillus cereus, Bacillus subtilis, Clostridium difficile, Clostridium perfringens, Mycobacterium tuberculosis, Mycobacterium terrae, Mycobacterium avium , Poliovirus, Adenovirus, Norovirus, Vaccinia virus, influenza virus, Hepatitis B virus, Human Immunodeficiency virus, and/or Human papilloma virus.

17 . A disinfectant composition comprising:

a first biocide comprising a carbonate/bicarbonate salt of a quaternary ammonium cation;

a second biocide selected so as to synergistically operate in conjunction with the first biocide in order to kill or inhibit growth of a microorganism, the second biocide comprising an alkyl quaternary ammonium halide, a benzyl ammonium halide, a quaternary ammonium propionate, a tertiary amine, or a pyrithione, and wherein the second biocide is present in relation to the first biocide such that the ability of both biocides to kill or inhibit the growth of the microorganism is greater than if only one of the biocides were present at the same concentration of both biocides together; and

one or more aids selected from the group comprising solvents, surfactants, sequestering agents, complexing agents, corrosion inhibitors, alkalinity builders, pH adjusting agents, preservatives, auxiliaries, acids, foaming agents, perfumes, and colorants.

18 . A cosmetic or hygiene product comprising:

a base formulation; and

a preservative, the preservative comprising a composition according to claim 17 .

19 . A method for disinfecting an adjacent object comprising:

contacting the adjacent object with the composition as defined in claim 1

20 .- 27 . (canceled)

28 . A method as defined in claim 19 , wherein the first biocide comprises a carbonate/bicarbonate salt of a quaternary ammonium cation.