A comparative investigation of the bactericidal and fungicidal effects of three phenolic disinfectants.

Two methods, a capacity use-dilution test and another employing geometrical dilution, are used when comparing the bactericidal and fungicidal effects of a phenolic disinfectant containing 45% (w/w) o-phenylphenol in an aqueous soap solution of linseed oil (soap content 6.5% w/v) with the corresponding effects of the same phenolic compound in an aqueous soya oil soap solution (soap content 3.5% w/v). The soya oil soap did not change the disinfectant capacity on the different test organisms used. For the most resistant strain (Staphylococcus aureus) the usedilution concentration was evaluated to be slightly above 196, i t . 2%, which is much lower than the recommended use-dilution concentration. However, using the same method and test organisms the capacity use-dilution testing of a third phenolic disinfectant, containing p-chlorom-cresol and o-benzyl-p-chlorophenol with a total of 9.2 (w/w) phenols in a detergent system, indicated that the recommended use-dilution concentration should be doubled.