Skin vapour loss as a method for measuring the influence of soaps and detergents on human skin. (Part 1).

The influence of a number of liquid soaps and detergents on the barrier function of the human skin was investigated by means of skin vapour loss (S.V.L.) measurements. Five liquid cleansers for body use and two liquid dish-cleansers were assayed on the volar side of the forearm. The measurements were performed on 20 healthy volunteers before and after the application of 1 ml of 2 vol.% solution. Five testpersons had to be excluded from the group because of theoretical reasons. The effect on the skin by the applied soaps and detergents was expressed in the average increase of S.V.L. X C. A considerable intra- as well as inter-subject variation of S.V.L. after the application of the test substances could be noted. Each person showed his own pattern of susceptibility. Skin reactions to soaps and detergents as measured by S.V.L. depend not only on the nature of the tested substances but also differ considerably from one person to another. The osmolarity of a test solution may play a role of importance in the irritant effects of soaps and detergents.