It is told of a toxic contact dermatitis of a mason with hitherto intact skin. One is searching for the reason of this rarely appearing skin damage by taking into consideration the chemical process during the cement preparation as well as in the following working process. The low number of cases known so far in relation to the millions of tons of processed cement on the one hand and the serious professional consequences for the persons concerned on the other have caused us to discuss once again the causal correlations in this essay.
