Updated March 2022
Chromium-6 is the cancer-causing chemical made notorious by the film “Erin Brockovich,” which documented how the chemical contaminated drinking water in Hinkley, Calif. Chromium-6 gets into drinking water through pollution from industrial uses and from hazardous waste sites, but it also occurs naturally in some areas. Among other uses, it serves as a coolant at electrical power stations.
In 2008, the National Toxicology Program, or NTP, found that water contaminated with chromium-6 causes cancer in laboratory animals. In 2010, California scientists published a health protective level of 0.02 parts per billion, or ppb, for chromium-6 in drinking water. This value is five thousand times lower than the national legal limit for total chromium in drinking water of 100 ppb. Total chromium includes chromium-6 and trivalent chromium.
Despite the NTP’s findings and California’s move to set a much stricter health protective level, there is no national standard for chromium-6 in drinking water. The Environmental Protection Agency’s health safety review of the chemical has been stalled for over a decade by the industries responsible for chromium-6 contamination.