Chromium is an odorless and tasteless metallic element. Chromium is found naturally in rocks, plants, soil and volcanic dust, and animals. The most common forms of chromium that occur in natural waters are trivalent chromium (chromium-3) and hexavalent chromium (chromium-6). Chromium-3 is an essential dietary element. It is found in many vegetables, fruits, meats, grains, and yeast. Chromium6 occurs naturally in the environment from the erosion of natural chromium deposits. Chromium-6 can also be produced by certain industrial processes.