ANIMAL HUSBANDRY SANITIZING COMPOSITIONS
This invention relates to chemical compositions,with high oxidising capabilities, which are intended to be used as working sanitizing solutions within the practice of animal husbandry and which are so strength designated that they comply with the various requirements of the United Kingdom's "Animal Health Act 1981" in terms of dilution rates which are suitable to combat the notifiable diseases scheduled therein. The diseases embraced within the Act are varied in the species which are infected and in the causative agents involved and the latter can range from the bacillus of Tuberculosis to the viral strains of Foot & Mouth Disease.
Ever since Bleaching Powder was produced in the United Kingdom some 200 years ago it was employed as a dilute aqueoous solution in medicine for the treatment of infected wounds and for sanitising dressings,instrmnents and working surfaces and as far back as the 3. P.C. of 1907 the use of dilute solutions of calcium hypochlorite (Dakin's Solution) for wound irrigation is recorded In all subsequent disinfectant research which is recorded until the early 1930's chlorine under alkaline conditions (hypochlorite) was the main source of microbiocidal activity especially for the large scale disinfection of floors ,walls and animal houses.Hypochlorites were the only source of active chlorine for sanitising use and they had to be used under alkaline conditions in order to ensure that their hypochlorite ions were bound strongly enough so as not to decompose and evolve toxic chlorine gas. It was known however that chlorine water,uhich was not alkaline,was a more powerful disinfectant than the alkaline hypachlorites,activity for activity,but it was not until 1961 that the DuPont Company taught, in G.B.932,750,that chlorine could be employed in strong solutions under acidic conditions if the compositions contained a nitrogeneous compound which could act as a chlorine-hypochlorite acceptor and therein named various acceptors such as sulphamic acid,urea,melamine and formamide.
In this DuPont work the concept of generating chlorine under acidic conditions from an oxidizing agent, such as a persulphate,and a metal halide, such as sodium chloride1 was introduced and has proliferated within the prior art ever since. For example in G.B.2,164,851 a metal halide with a persulphate is used in the presence of a chlorine acceptor but the basic formulation structure of GB.932,750 has only been altered to contain a non-reducing organic acid and an acid phosphate salt which was reported to stabilize the pH value of the working solutions and thereby endow the prepared sanitising solutions with better chlorine retention.Two years later in G.3.2,187,098 the same qualitative formulations are cited but this time the amounts of persulphate and metal halide are greatly reduced in order to stabilize the powder mixture under storage conditions where it might be contaminated with small amounts of moisture and thereafter cake and evolve some chlorine into the atmosphere of the farm store. Finally, in GB 2,078, 522B the basis of the DuPont technology is reproduced with the chlorine source being either calcium hypochlorite or Dichloramine
T with sulphamic acid retained as the chlorine acceptor together with non-reducing organic acids as the source of low pH values in solution so that high concentrations of corrosive sulphamic acid are not required.With this prior art in mind II inv- estigated the microbactericidal properties of sodium persulphate in the form of its triple salt known as Caro's Acid Triple Salt and concluded that it was a powerful and rapid bactericide under acid conditions but that its activity was greatly reduced if the pH value of its working solutions were allowed to approach pH 9.Little was known about its viricidal properties so the situation was investigated using the acid triple salt in the form of a solution of a powder prepared from the persulphate together with sulphamic acid,a surfactant,and an alkali metal phosphate and it was found to behave as a highly active viricide when tested against standard strains which are are responsible for Foot & Mouth Disease,Swine Vesicular Disease, Newcastle Disease and a series grouped under the Act as General Orders and representing diseases such as Anthrax,Brucellosis,Bovine Pleuropneumonia and Glanders.Formulations such as those outlined above are stable and without the characteristic odour of available chlorine but since it was thought that such an odour was commercially important because of the long history of the use of hypochlorites in the animal husbandry business it was decided to add a chlorine adjunct in the form of sodium dichloroisocyanurate.
Zhen this substance was added in quantities as little as 5%w/w and the powder tested as before it was found that although the oxidising capability had changed but little the results were greatly improved in terms of dilution rates necessary to combat the diseases scheduled under the Act. Experience has shown that the persulphates dis play greater bactericidal activity than either hydrogen peroxide or available chlorine 80 it was a surprise t find that the presence of small amounts of available chlorine under acid conditions enhanced the previously obtained dilution rates for the scheduled aminal diseases.Accordingly therefore there is now disclosed an invention in the form of an animal husbandry sanitizing composition, in solid form,comprising an alkali metal perslJlphate as its triple salt and acting as the strongly oxidising sou rce,sulphamic acid as the strongly acid medium, a sequestering alkali metal phosphate, a surfactant and an organic source of available chlorine in the form of a chlorinated isocyanurate.The following example illustrates the invention but in order to dem- onstrate the effect of the presence of available chlorine on the composition's performance on challenging the organisms of the diseases scheduled under the U.K.'s "Animal
Health Act 1981" a similiar composition, without the presence of available chlorine,is appended and in these the dilutions quoted are those which give a 4 log reduction in the titre of the challenging virus.
SAMPLE, 1.
Composition(w/w) Dilution Pates under the Act Caro's Acid Triple Salt 50% Newcastle Disease 230
Sulphamic Acid 15% Foot & Mouth Disease 800 to 900
Sodium Dosecylbenzene Sulphonate 5% Swine Vesicular Disease 170 to 180
Sodium Hexametaphosphate 30% General Orders Requirement about 100
The dilution rates obtained for the composition of Example 1 represent a product which under normal farm conditions of hard water and animal soiling,would be considered to have adequate virucidal activity.
EXAMPLE. 2 ComPosition(w/w) Dilution Rates under the Act Caro's Acid Triple Salt 50s Newcastle Disease 270-280
Sulphamic Acid 15% Foot & Mouth Disease 1000-1200
Sodium Dodecylbemzene Sulphonate 5% Swine Vesicular Disease 200 -220
Sodium Dichloroisocyanurate 5% General Orders Requirements 120-130
Sodium Hexametaphosphate 25%
It is apparent that the 17% to 33 permitted increase in dilution rates of the composition of Example 2 cannot be attributed to any significant increase in the oxidation potentials of the persulphate/chloroisocyanurate blend and whilst it is not part of this disclosure to prove any chemical mechanism involved in the invention we believe that the effect is due to the capability of the chloroisocyanuric acid moiety to oscillate between the chlorinated state and isocyanuric acid itself so that when the chlorinated form acts as a viricide and reverts or decomposes into isocyanuric acid and chloride the latter is in;mediately oxidised to regenerate the chlorinated form of the isocyanuric acid which is again available to act as the viricidal agent.
The compositions of Example 1 and Example 2 are acidic in reaction with pH values around 2.1 to 2.2 which means that the potential for chlorine evolution during use of the working solutions is extremely small because of the presence of the sulphamic acid which continues to act as a chlorine acceptor according to the previous teachings of G.B.932,750. The product of Example 2,which is the subject of the invention, contains no chloride in the solid state so the danger of chlorine Fvolts nn on damp storage is non-existent.