Measurement of the permeation of textile auxiliaries through the skin

Although the available amount of auxiliaries contained in textiles should be low, there may be a considerable transdermal risk because of the great area of exposure. Furthermore, the passage of substances contained in clothing could be increased by sweat or mechanical abrasion. On regarding some thousand chemicals used as auxiliaries, there are two classes of substances that attract special attention as they bear a cancerous risk: formaldehyde, used in great extent for resin-finishing of cotton, and several azo dyes, that can be metabolized to carcinogenic aryl amines. In order to enable measurement of low concentrations of permeants, a static permeation chamber is used. Substances are applied on textile samples to human skin with or without sweat. The chamber is slightly closed to atmosphere to prevent dehydration of skin and evaporation. The method has been tested with formaldehyde and with congo red as a model compound for benzidine derived azo dyes. Formaldehyde permeated the skin to some extent, the greatest amount however was expected to be bound to constituents of skin, e.g. to proteins. Congo red was completely absorbed at the stratum corneum