Chromium-6 (hexavalent chromium)
Health & what it is
Hexavalent chromium (chromium-6) is a form of chromium that can occur naturally and from industrial pollution. It became widely known through the Hinkley, California, contamination case.
Inhaled chromium-6 is a known carcinogen; the cancer risk from drinking it is an area of ongoing study, and some states treat it more strictly than the federal government does.
There is no separate federal limit for chromium-6 specifically — EPA regulates total chromium at 100 parts per billion (ppb). California has set a state-level chromium-6 limit, reflecting its stricter stance.
Where it comes from
Natural deposits and industrial discharges (electroplating, manufacturing, cooling-tower additives).
How to reduce Chromium-6 at home
Look for a filter certified to NSF/ANSI 53 or 58 — Reverse osmosis or arsenic-specific adsorptive media.
- ✓Reverse osmosis
- ✓Anion exchange designed for chromium
- ✓Certain reduction/filtration treatment systems
Frequently asked questions
What is Chromium-6? +
The “Erin Brockovich” chemical. EPA regulates total chromium; California sets a separate Cr-6 limit. Natural deposits and industrial discharges (electroplating, manufacturing, cooling-tower additives).
What is the EPA limit for Chromium-6 in drinking water? +
The EPA limit is 100 ppb (total chromium). To remove it, look for a filter certified to NSF/ANSI 53 or 58.
What are the health effects of Chromium-6? +
Hexavalent chromium (chromium-6) is a form of chromium that can occur naturally and from industrial pollution. It became widely known through the Hinkley, California, contamination case. Inhaled chromium-6 is a known carcinogen; the cancer risk from drinking it is an area of ongoing study, and some states treat it more strictly than the federal government does. There is no separate federal limit for chromium-6 specifically — EPA regulates total chromium at 100 parts per billion (ppb). California has set a state-level chromium-6 limit, reflecting its stricter stance.
How do you remove Chromium-6 from drinking water? +
Reverse osmosis Anion exchange designed for chromium Certain reduction/filtration treatment systems
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