Chromium-6 (Hexavalent Chromium)

Category: inorganic

Written by WaterFilterMatch Editorial TeamApril 2026

EPA MCL

0.1 mg/L

MCL is for total chromium (all forms); no separate chromium-6 MCL

Status

EPA Regulated

NSF Standard

NSF/ANSI 53 (some filters), NSF/ANSI 58

Health Effects

Known human carcinogen when inhaled; associated with stomach and intestinal tumors in animal studies when ingested. Also linked to allergic dermatitis. Note: the EPA MCL of 0.1 mg/L is for total chromium, not specifically hexavalent chromium.

Source: EPA National Primary Drinking Water Regulations

Where It Comes From

Discharge from steel and pulp mills, erosion of natural deposits. Also from industrial uses in metal plating, leather tanning, and wood preservation. Can be naturally occurring or from industrial contamination.

Where It's Commonly Found

Widespread - EWG estimates chromium-6 is present in the drinking water of over 250 million Americans. California has established a separate public health goal of 0.02 ppb specifically for chromium-6.

Over 250 million Americans served by water systems with detectable chromium-6 (per EWG). Most systems are below the EPA total chromium MCL but often exceed EWG's recommended health guideline of 0.02 ppb.