EWG Tap Water Atlas

Chromium (hexavalent)

Hexavalent chromium, also known as chromium-6, is a chemical made notorious by the film “Erin Brockovich.” In tap water, it can cause stomach and intestinal cancer, as well as damage to the liver and reproductive systems.

Chromium-6 has been found in the tap water of almost 250 million people in all 50 states. It can infiltrate drinking water through pollution from industrial uses, such as a coolant at electrical power stations. It also occurs naturally in some areas.

There is no federal legal limit for chromium-6 in tap water. EWG’s health guideline is 0.02 parts per billion, the amount the California Office of Environmental Health Hazard Assessment says is expected to cause no more than one case of cancer in 1 million people who drink it for a lifetime.

Consumers can filter out chromium-6 with ion-exchange pitcher filters and under-sink reverse osmosis filters. Reverse osmosis is more expensive.