Contact sensitivity to trivalent chromium compounds.

The investigations confirmed the known fact that for skin tests larger amounts of trivalent chromium compounds are necessary than those of potassium dichromate. It was also observed that some patients react to relatively higher Cr VI and lower Cr III concentrations and others vice versa. Chromium nitrate and chloride release and that of potassium dichromate was determined and converted to the chromium content in the concentrations used for skin tests. It was found that Cr III compounds cannot be used for skin tests in a 0,5% concentration if only because they are released in undeterminable amounts. Release of Cr III and potassium dichromate from bases containing the same amount of substance when converted to chromium demonstrated that the different release of Cr III is not an additional cause of the fact that much higher concentrations of Cr III compounds have to be used for patch tests than those of Cr VI compounds.