On February 9, 2026, the California Environmental Protection Agency's Office of Environmental Health Hazard Assessment (OEHHA) announced the finalization of a health protective concentration (HPC) of 5 parts per billion (ppb) for non-carcinogenic effects of hexavalent chromium (Cr(VI)) in drinking water. The 5 ppb standard is based on a chronic toxicity study in which female rats exposed to hexavalent chromium in drinking water over the long term developed chronic liver inflammation.
Background
Hexavalent chromium is a highly toxic heavy metal compound commonly found in industrial pollution. Long-term exposure through drinking water can lead to various health issues. Since the implementation of California's Safe Drinking Water Act in 1996, the state has continually tightened control standards for such carcinogens.
Key Conclusions
|
Item |
Content |
|
Updated Non-Carcinogenic HPC |
5 micrograms per liter (μg/L), equivalent to 5 ppb |
|
Previous HPC (2011) |
2 ppb |
|
Key Study |
National Toxicology Program (NTP, 2008a) 2-year chronic toxicity study |
|
Most Sensitive Endpoint |
Chronic liver inflammation in female rats |
Under the California Safe Drinking Water Act, OEHHA is required to separately evaluate health risks for carcinogenic and non-carcinogenic effects, ultimately adopting the most stringent (lowest) value as the Public Health Goal (PHG). The HPC for carcinogenic effects is still under development and will be announced separately.
