Background Art Biocide compositions are well known. Some are based on single chemical components and others are formulations made by combining multiple chemicals. Since many biocides are chemically neutralized and thereby inactivated by organic matter, it is important to thoroughly clean the area to be disinfected before using those biocides.

A good example of this is hypochlorous acid or bleach, a good biocide under clean conditions but it has the disadvantage of being less effective in practical situations.

Those skilled in biocide technology know that many biocides are inactivated by detergents. This fact becomes critically important in the field of hand washes in hospitals when staff use one hand wash when they simply need to clean their hands or first arrive at work, and a different hand wash when they need to remove bacterial contamination. Anionic components are often used in the cleansing hand washes, and Chlorhexidine is commonly used as the biocidal component in the anti-microbial hand washes, but anionic chemicals inactivate chlorhexidine.

High toxicity profiles make many currently used biocides unacceptable.

Glutaraldehyde is widely used for the decontamination of flexible endoscopes, but the vapour it releases is believed to cause occupational asthma.

EP 0836803 discloses an aqueous disinfecting composition comprising from 1 to 20% aldehydes, especially glutaraldehyde, 3 to 35% salts, especially quatemary

ammonium chlorides, 1 to 15% ethoxylated fatty alcool, and from 0.5 to 15% of an insecticidal agent selected from synthetic pyrethroids. Although this composition has the advantage of a cleaning component, the aldehyde component still produces toxic vapours and the alcohol has the disadvantage of being flammable.

Disclosure of Invention It is an object of this invention to provide a biocide composition with both cleaning and disinfecting capacity and which is safe for general and widespread use.

It is a further object of this invention to provide a biocide composition which is usable in both the solid and liquid forms.

Accordingly, the invention provides a biocide composition comprising at least one of each of the following : (I) a surface-active chemical (ii) an aldehyde, and (iii) a complexing agent.

The invention also provides for a biocide composition comprising at least one non-volatile aldehyde.

In addition, the invention provides for a biocide composition which is provided in a solid form and subsequently dissolved in a solvent including, but not exclusively, water to make a biocidal solution.

Brief Description of the Table Eighteen formulations are shown which collectively provide evidence of the poor effectiveness of prior art formulations against bacterial spores and Polio virus, compared to the effectiveness of formulations based on the invention.

The Polio virus tests followed the protocol of Nagington and colleagues published in the British Journal of Ophthalmology, 1983, volume 67, page 674, and

were performed by a member of that team. The spore tests were based on the following protocol: filter-paper discs of several millimetres diameter were dipped into a suspension of Bacillus subtilis spores, air dried and stored. When required the contaminated discs were dipped into the test formulation for the required contact time of five minutes, removed and placed into 20 ml of Bacillus growth medium with the dilution ratio being used to terminate the anti-microbial activity. Control contaminated discs were dipped for five minutes in growth medium rather than disinfectant and subsequently treated in the same manner as the test discs. That growth medium containing the discs was incubated for an appropriate number of days, and then a sample was plated onto the appropriate agar and the plates incubated. In the following data, if one or more colonies grew on the agar the formulation was deemed to have failed as a sporicide. If no colonies were seen on the agar, but the control plates had heavy growth, the formulation was deemed to have passed as a sporicide.

Formulation Ingredients Bacterial Polio Number Spores Virus 1. 8% Didecyidimethylethoxy ammonium chloride 0.7% Benzalkonium chloride 0.4% Cocopropylenediamine guanidinium acetate Fail 2 1 + 0. 05% EDTA Fail 3 0. 5% OPA in water Fail 4 Water alone Fail 5 1 + 0. 1 % OPA Fail 6 1 + 0.05% EDTA + 0. 1% OPA Pass 7 2% Alkyl dimethylbenzalkonium chloride Fail 8 7+ 0. 05% EDTA Fail 9 7 + 0.25% OPA Fail 10 7 + 0.05% EDTA + 0.25% OPA Pass

11 0.05% Didecyidimethyl ammonium chloride 0.05% Aikytdimethytbenzyt ammonium chloride Fail 12 11 +0. 05% EDTA Fail 13 11 + 0. 25% OPA Fail 14 11 + 0.05% EDTA + 0.25% OPA Pass 15 2% Cetyttrimethyt ammonium bromide Fail 16 15 + 0.05% EDTA Fail 17 15 + 0. 25% OPA Fail 18 15+ 0. 05% EDTA+ 0. 25% OPA Pass These results clearly show the advances brought by the QAC, EDTA and aldehyde combination. Formulation 1, a commercially available disinfectant, failed to kill spores, but with the addition of 0.25% OPA it became sporicidal, whereas with 0.1% added OPA it did not. OPA alone in water at 0.5% failed to kill spores. Therefore the minimal sporicidal level of OPA is greater than 0.5% when tested alone and greater than 0.1% when used in a synergistic mixture with QAC's. Formulation 6, the commercially available product of Formulation 1 with 0.1% OPA and 0.05% EDTA added, was sporicidal.

Formulations 7 to 10 followed a similar sequence but with a single QAC. The QAC failed to kill spores when used on its own or when mixed with either 0.05% EDTA or 0.25% OPA, but the combination of all three was sporicidal.

Formulations 11 to 14 followed the same sequence with a known product based on two QAC's tested against polio virus. The combination of the two QAC's on its own failed to kill polio virus, and the addition of either 0.05% EDTA or 0.25% OPA failed to alter that result. But adding both 0.05% EDTA and 0.25% OPA to the two QAC's produced a formulation that killed polio virus.

Formulations 15 to 18 are based on 2% cetyltrimethyl ammonium bromide, a QAC that is a solid at ambient temperatures. Adding either 0.05% EDTA or 0.25%

OPA alone failed to make it sporicidal, but adding 0.05% EDTA and 0.25% OPA together made it sporicidal. Formulation 18 is a biocide solution made by dissolving the solid biocide composition made up of solid QAC, EDTA and OPA in water.

Best Modes of Carrying Out the Invention The best modes of carrying out the invention relate to the choice of QAC and the decision of whether one or more than one QAC should be used. The QAC group offers a wide variety of features-some are excellent conditioners of skin and fabrics, others have particularly good cleaning properties and others are solids at ambient temperatures which allows for powdered formulations that can additionally be formed into tables.

The example formulation below, which is based on this invention, will demonstrate the best mode of carrying out the invention.

INGREDIENT % WV Benzalkonium chloride 0.01-5.0 Didecyidimethyethoxy ammonium chloride 0.01-5.0 Amine Oxide 0.01-5.0 Ethylene diamine Tetra Acetic acid 0.01-5.0 Orthophthalaldehyde 0.01-0.5 Water To 100% The QAC's and amine oxide are mixed at room temperature, the EDTA and OPA are dissolved into that mixture and a pH modifier is added slowly until the desired pH is achieved. The appropriate amount of water is then added, depending on whether a concentrate or the use dilution is required.

Readers will understand that the formulations and components quoted here are by way of example only and do not represent the limit of the possible choices of surface active agent, complexing agent or aldehyde, nor the concentrations to be used.

OPA was selected as the example aldehyde because it is a solid thereby allowing for the powdered composition that was dissolved in solvent, in this case water, to provide formulation 18.

Industrial Application The invention provides biocide compositions suitable for safe and widespread use in the cleaning, sanitising, disinfecting and sterilising fields in all industries and markets.