What Is Hexavalent Chromium?
It is one form of the metal chromium. ATSDR says the metal form, chromium(0), is used for making steel, while chromium(VI) and chromium(III) are used for chrome plating, dyes and pigments, leather tanning and wood preserving.
ATSDR says chromium(VI) at high levels can damage the nose and cause cancer, and that ingesting high levels may result in anemia or damage to the stomach or intestines. IARC concluded there is sufficient evidence in humans that chromium(VI) compounds cause cancer of the lung, with positive associations also observed for cancer of the nose and nasal sinuses, and classifies them as carcinogenic to humans, Group 1. The National Toxicology Program lists chromium(VI) compounds as known to be human carcinogens.
California regulates it in drinking water. The State Water Resources Control Board’s maximum contaminant level for hexavalent chromium is 0.010 mg/L, or 10 µg/L, under a rulemaking effective October 1, 2024, and community and nontransient noncommunity water systems had to complete initial sampling on or before April 1, 2025.
Sources checked September 15, 2026. Every point below links the page it came from.
The sources behind this answer
- Government sourceATSDR says chromium(0) is used for making steel, while chromium(VI) and chromium(III) are used for chrome plating, dyes and pigments, leather tanning and wood preserving. ATSDR ToxFAQs ↗
- Government sourceATSDR says chromium(VI) at high levels can damage the nose and cause cancer, and that ingesting high levels may result in anemia or damage to the stomach or intestines. ATSDR ToxFAQs ↗
- Government sourceIARC found sufficient evidence in humans that chromium(VI) compounds cause lung cancer, with positive associations for cancer of the nose and nasal sinuses, and classified them as carcinogenic to humans (Group 1). IARC Monographs Volume 100C, via NCBI Bookshelf ↗
- Government sourceThe National Toxicology Program’s 15th Report on Carcinogens lists chromium hexavalent (VI) compounds as known to be human carcinogens based on sufficient evidence from studies in humans. National Toxicology Program, via NCBI Bookshelf ↗
- Regulatory filingCalifornia’s State Water Resources Control Board says the hexavalent chromium maximum contaminant level is 0.010 mg/L, or 10 µg/L, under a rulemaking effective October 1, 2024. California State Water Resources Control Board ↗
- Regulatory filingUnder California’s hexavalent chromium rule, community and nontransient noncommunity water systems had to complete initial sampling on or before April 1, 2025. California State Water Resources Control Board ↗
Sources checked September 15, 2026. A brand statement is the company’s own claim, which we report but have not verified. Our grades are model-based estimates, not lab tests.