Hydrochlorothiazide, Voriconazole, and Tacrolimus Added to the Proposition 65 List for Cancer

Effective July 17, 2026, the Office of Environmental Health Hazard Assessment (OEHHA) is adding hydrochlorothiazide, voriconazole, and tacrolimus to the list of chemicals known to the State of California to cause cancer under the Safe Drinking Water and Toxic Enforcement Act of 1986, sections 25249.5 et seq. of the Health and Safety Code, otherwise known as Proposition 65. The listing of these chemicals is pursuant to the “Labor Code” listing mechanism (Health and Safety Code, section 25249.8(a); Cal. Code of Regs., title 27, section 25904).

The basis for the listings was described in a public notice published in the May 8, 2026 issue of the California Regulatory Notice Register (Register 2026, No. 18-Z). The title of the notice is “Notice of Intent to List Chemicals by the Labor Code Mechanism: Hydrochlorothiazide, Voriconazole, and Tacrolimus.” The publication of the notice initiated a public comment period May 8, 2026 – June 8, 2026). No comments were received during the comment period. 

A complete, updated Proposition 65 chemical list is available on the OEHHA website.