Forearm wash test to evaluate the clinical mildness of cleansing products

Abstract

A forearm wash test was developed to differentiate the mildness of personal cleansing products, e.g., bar soaps. The wash protocol was derived from habit information and by observation of actual wash situations. The method was found to be sensitive enough to discriminate differences in bar composition such as tallow/coconut ratio, presence of super fitting, and type of synthetic surfactant. There are design variations to accommodate paired comparisons and single product comparisons of multiple products. Dew point was a key indicator of responsiveness to soap treatment. Therefore, the number of washings was increased to allow product differentiation under conditions of high dew point. Because the method was derived from actual washing situations, it is more likely to be predictive of consumers' skin condition when using cleansing products than are the conventional chamber or patch tests.