Toxicological or carcinogenic effects have not been detected in rats receiving up to 5% chromium(III) oxide in their feed [3.81] nor in medical studies performed in chemical plants producing chromium(III) oxide and chromium(III) sulfate [3.82]. The oral LD50 for chromium(III) oxide in the rat is >10,000 mg kgg ; it does not irritate the skin or mucous membranes.
Chromium(III) oxide is not included in the MAK list (Germany), the TLV list (USA), or in the list of hazardous occupational materials of the EC [3.83]. In practice, this means that chromium(III) oxide can be regarded as an inert fine dust with a MAK value of 3 mg m-3 [3.84].
3.1.3