[0130] Recipe 12 corresponds in terms of the composition to recipe 8, but was titrated with KOH (50%) to an elevated pH of >5.0 in order to determine the influence of pH on antimicrobial efficacy. Here, the consumption of KOH (50%) was 12.0 g. Since the large amount of pH regu!a_tor resulted in an increase in the total amount of the compos1t10n from 100 g to 112 g and this consequently leads to a reduction in the proportion of the acids, the application concentration was increased in order to have the same amount of active organic acids in the respective test solu› tions. 

[0131] Composition 8, which has a native pH of 2.64, corresponds to a composition containing 100 g and was tested as 3% test solution. The pH-altered recipe 12 corre› sponds to 112 g and was consequently tested as 3.36% composition. In order to be able to show a better compara› bility between the recipes and efficacies, the converted data were, for recipe 12, stated as 100 g of concentrate and accordingly 3% test concentrations. 

[0132] Recipe 14 involved a native pH of 0.86; recipe 15 involved a native pH of 1.57. In order to minimize any influence on efficacy by deviating pH values, the pH values were adjusted here by addition ofKOH(50%) to pH 2.25 and pH 2.31, respectively. In the case ofrecipe 14, the necessary amount of for this pH was 1 g ofKOH(50%); in the case of recipe 15, this was just 0.8 g. The corresponding amount of demineralized water was substituted in order to continue to have 100 g of recipes. In order to be able to present a better comparability in the overview, the recipe overview lists, however, the amount as water, with a pH regulator being noted. 

[0133] The results of Example 3 and Example 1 show that substitution of 15% lactic acid with 15% propionic acid can achieve a significant increase in efficacy on Candida albi› cans. What is crucial here is that, as a result of this substitution, altogether four acids are used and no longer just three, though instead in higher amounts. This is also con› firmed by Examples 6 and 7: 

[0134] The addition of 15% acetic acid significantly increases efficacy again, as shown by the comparison of the efficacy data of the Candida albicans screening. This increase in efficacy is unexpected for a person skilled in the art and confirms the synergism, since Comparative Example V6, a significantly higher concentration of acetic acid in application solution, exhibits no efficacy with respect to Candida albicans even at a relatively long exposure time. 

[0135] The comparison of Example 14 and Example 8 demonstrates that the efficacy synergism with four acids leads to an even better pathogen reduction than three acids. What is involved here is a comparable composition differing only in a proportion of 6% sodium benzoate or 6% water. Recipe 8, which is based on four acids as active ingredients, achieves the maximum reduction (RF> 7) on Mycobacterium terrae and Staphylococcus aureus within an exposure time of 15 minutes at 3% application concentration. By contrast, recipe 14 exhibits at this low concentration "merely" a reduction factor of 4.95 on Mycobacterium terrae and insufficient efficacy on Staphylococcus aureus (RF<5.0). 

[0136] A comparison of recipe 7 with recipe 15 with efficacy data on Candida albicans and Staphylococcus aureus confirms the finding presented above. 

[0137] Thus, the difference between the two recipes is merely the 6% benzoate and the resulting reduction factors of recipe 7 containing acetic acid, propionic acid, lactic acid 

and sodium benzoate are significantly better than those of recipe 15 containing acetic acid, propionic acid and lactic acid. 

[0138] Although the acetic acid in Example 1 is, in com› parison with Example 7, increased from 15% to 44%, the absence of the 15% propionic acid appears to have the greater negative influence on the efficacy with respect to Candida albicans. Moreover, the propionic acid brings about a positive influence on solubility, as already described under "Preparation of the concentrates and application dilu› tions". 

[0139] The results of Example 1, 8 and 9 show that, moreover, the combinations of the acids used can achieve a sufficient efficacy against Mycobacterium terrae. 

[0140] Comparative Example V9 merely contains 15% propionic acid and acetic acid and exhibits, only as 5% solution, a sufficient efficacy with respect to S. aureus after 45 minutes and, up to 5%, no efficacy on Candida albicans 45 minutes. Recipe 13 corresponds to the composition of Comparative Example V9; however, 6% water was replaced here by tartaric acid. The direct comparison of Example 13 with V9 on Staphylococcus aureus shows an increase in efficacy due to addition of tartaric acid to the existing combination. 

[0141] The recipe of V9 containing the two acids acetic acid and propionic acid can, however, also be compared well with Comparative Example V2: recipe V2, consisting of 15% propionic acid and 6% sodium benzoate, exhibits absolutely no efficacy with respect to S. aureus at 5% concentration and exposure time of 45 minutes, but a sufficient efficacy with respect to Candida albicans from 4% and 30 minutes. If, then, these recipes, V9 and V2, are combined to form 15% propionic acid, 15% acetic acid and 6% sodium benzoate, corresponding to Example 10, a significant increase in efficacy with respect to S. aureus is surprisingly found, according to which just a 3% application dilution after an exposure time of 45 minutes, or a 4% application dilution after 15 minutes, leads to a reduction factor ofRF>7 .0. This improvement is highly unexpected on the basis of the individual results. 

[0142] In this connection, it is also surprising that an increase in the content of sodium benzoate from 6% to 13% in the presence of 15% propionic acid leads to a distinct increase in efficacy with respect to Staphylococcus aureus. 

[0143] Example 9, which already achieves a maximum pathogen reduction on Staphylococcus aureus after an expo› sure time of 5 minutes, demonstrates that increasing the test concentrations can also achieve distinctly faster exposure times. Furthermore, recipe 16, consisting of 15% acetic acid and 15% propionic acid and 13% sodium benzoate, shows that a 5.5% application concentration can already achieve, after an exposure time of 2 minutes, sufficient efficacy with respect to Candida albicans and Staphylococcus aureus. Moreover, this recipe shows that, as a result of the use of the corresponding acid salts, a good regulation of pH can be used and the antimicrobial efficacy nevertheless remains unchanged. 

[0144] It was possible to show that synergic compositions containing organic acids are possible, with the best antimi› crobial efficacies being obtained in the case of compositions containing at least three components. 

## CONCLUSION 

