Substance AdditionLiveSubstance Addition
N-Methyl-N-Formylhydrazine Added to Prop 65 List for Cancer
California Proposition 65 (Safe Drinking Water and Toxic Enforcement Act of 1986)Office of Environmental Health Hazard Assessment (OEHHA)California
Announced
Dec 5, 2025
Effective
Dec 5, 2025
Implementation
Dec 5, 2025
Description
OEHHA added N-Methyl-N-Formylhydrazine to the Proposition 65 list as known to cause cancer. This chemical is now subject to California's warning requirements under Prop 65. Businesses with products containing this substance that may result in exposures in California should evaluate their warning obligations.
Sources
Key Findings
N-Methyl-N-Formylhydrazine Added to Prop 65 List for Cancer
[Skip to main content](https://oehha.ca.gov/proposition-65/crnr/n-methyl-n-formylhydrazine-added-proposition-65-list-cancer#main-content) [Skip to Main Content](https://oehha.ca.gov/proposition-65/crnr/n-methyl-n-formylhydrazine-added-proposition-65-list-cancer#main-content) [CA.gov CA.gov](https://ca.gov/) Official website of the State of California Reset High contrast Increase font size Font increase Decrease font
N-Methyl-N-Formylhydrazine Added to Prop 65 List for Cancer
tions, section 27001, is provided here, and is available on the website of the Office of Environmental Health Hazard Assessment (oehha.ca.gov). [...] Bis(chloromethyl)ether cancer 542-88-1 February 27, 1987 Bis(2-chloro-1-methylethyl)ether, technical grade cancer --- October 29, 1999 Bisphenol A (BPA) female 80-05-7 May 11, 2015 Bisphenol A (BPA) developmental 80-05-7 December 18, 2020 Bisphenol S (BPS) female 80-09-