The hazards of hexavalent chromium compounds are significantly different from those of non-hexavalent chromium compounds. Hexavalent chromium compounds are confirmed human carcinogens, mutagens and developmental toxicants and have high acute toxicity. Non-hexavalent chromium compounds do not pose the same level of concern with regard to either chronic or acute toxicity.
Until 2011, all chromium compounds were treated as a single category under TURA. Starting in reporting year 2012, hexavalent chromium compounds are reportable as a separate category under TURA. The hexavalent chromium compounds category has been designated as a Higher Hazard Substance under TURA, so the reporting threshold is 1,000 lb/year.