Reduction of chromate in cement by iron sulfate.

Cement dermatitis is connected with chromate sensitivity. It can therefore be expected that "elimination" of chromate in cement would decrease the number of cases of cement dermatitis. Iron sulfate added to cement reduces the chromate completely and the 3-valent chromium is precipitated. An amount of 0.35% (w/w) iron sulfate, FeSO4 . 7H2O, is enough to reduce 20 microgram Cr6+/g cement. There is no technical side effect to the concrete. The iron sulfate is preferably added to cement when there is an intimate contact with skin, e.g. at floor laying, repairs and hand-made casting.