Standard Test Method for Evaluating Relative Effectiveness of Antimicrobial Handwashing Formulations using the Palmar Surface and Mechanical Hand Sampling

5.1 Hand hygiene is important for preventing the spread of many types of infections.

5.2 During routine activities, it is primarily the palmar surface, comprising palms, fingers, and finger pads, of the hands that may become contaminated with transient microorganisms. The contamination could then be transferred to articles touched or handled or to other parts of the body. Palmar contamination is used in Test Method E2784.

5.3 In Test Method E1174, incomplete drying of the experimentally contaminated hands dilutes the applied test product, thus compromising its activity. Application of a smaller volume of the microbial test suspension keeps the soil load to a reasonable level while allowing the hands to become visibly dry prior to application of the test material and reference formulation. These modifications are aimed at producing a better approximation of in-use conditions and a more realistic assessment of the test substance, thus providing a more reliable indication of product performance.

5.4 Unlike Test Methods E1174, E2755, and E2784, this test method enables a direct comparison between two formulations on the same subject. The test method also uses a mechanical scrubbing machine in conjunction with the glove juice technique for more efficient recovery of viable test bacteria from the palms. The mechanical sampling results in greater recovery of bacteria from the palms than conventional recovery methods, such as massaging.