Chromium chemistry and implications for environmental fate and toxicity

The same chemical properties that make chromium such an important component of so many industrial and consumer products are the important factors controlling its environmental fate and toxicity. Although only about 15% of the chromium mined is used in the manufacture of chromium chemicals, the chemistry of chromium is important in nearly all applications. For instance, the “stainless” nature of stainless steel is due to the chemical properties of the chromium oxides that form on the suriace of the alloy. Similarly, the product protection afforded by chrome plating of metals, CCA treatment of wood, and chrome tanning of leather is directly dependent on chromium chemistry. In all of these applications the most important chemical property is that under typical environmental and biological conditions of pH and oxidation‐reduction potential, the most stable form of chromium is the trivalent oxide. This form has very low solubility and low reactivity resulting in low mobility in the environment and low toxicity...