The Office of Environmental Health Hazard Assessment

About us

The Office of Environmental Health Hazard Assessment (OEHHA) is the lead state agency for the assessment of health risks posed by environmental contaminants. OEHHA’s mission is to protect and enhance the health of Californians and our state’s environment through scientific evaluations that inform, support and guide regulatory and other actions.  

OEHHA implements the Safe Drinking Water and Toxic Enforcement Act of 1986, commonly known as Proposition 65, and compiles the state’s list of substances that cause cancer or reproductive harm. The Office also develops health-protective exposure levels for contaminants in air, water, and soil as guidance for regulatory agencies and the public. These include public health goals for contaminants in drinking water and both cancer potency factors and non-cancer reference exposure levels for the Air Toxics Hot Spots Program.

Other key OEHHA activities include:

Developing fish advisories for mercury and other contaminants in sport fish from water bodies throughout the state, and making recommendations regarding fishing safety and closures after marine oil spills.
Collaborating with the California Department of Public Health and Department of Toxic Substances Control on the Biomonitoring California program, which measures levels of chemicals found in Californians’ bodies.
Developing a pioneering environmental health screening tool that can be used to put together a more comprehensive picture of the burdens California communities face from environmental pollutants and their vulnerability to health and economic impacts.
Identifying and analyzing Indicators of Climate Change in California.