Chromium sulfate

Chromium sulfate is commonly used as a leather preservative. It is often associated with cancer of the respiratory tract, skin ulcers, and renal failure. Smithsonian Magazine (November 2007) reports it to be a major source of effluent pollution in the Ganges River in Kanpur, India. A salt of chromium (Cr2(OH)SO4), in the form of green crystals that are soluble in water and form an acid solution. It is used in chrome tanning.