California Office of Environmental Health Hazard Assessment

Office of Environmental Health Hazard Assessment
OEHHA's logo
Agency overview
HeadquartersCalEPA Building, Sacramento, California
United States
Employees161 positions
Annual budget$34.2 mil total; $10.7 mil general fund
Agency executive
  • Kris Thayer, PhD, Director
Parent agencyCalifornia Environmental Protection Agency
Websitehttp://www.oehha.ca.gov

The Office of Environmental Health Hazard Assessment, commonly referred to as OEHHA (pronounced oh-EEE-ha), is a specialized department within the California Environmental Protection Agency (CalEPA). OEHHA is the lead state agency for the assessment of health risks posed by environmental contaminants. OEHHA evaluates harmful chemicals and other environmental hazards, such as extreme heat, to understand interconnected environmental health burdens faced by individuals and communities in California. This allows OEHHA to play a critical and unique role—providing independent analyses to inform science-based decision making.

As CalEPA’s scientific adviser, OEHHA works within CalEPA and across state government, with other state and federal agencies, businesses, community-based organizations, and communities and Native American Tribes across California to develop actionable science that protects public health, especially for those facing multiple environmental hazards.

OEHHA's current director is Dr. Kris Thayer, who was appointed by Governor Gavin Newsom on April 29, 2025. Previously, Dr. Lauren Zeise directed OEHHA from 2015 until 2024.