Chemical Listed Effective December 29, 2017 as Known to the State of California to Cause Cancer: Vinylidene Chloride (1,1-dichloroethylene)

Effective December 29, 2017, the Office of Environmental Health Hazard Assessment (OEHHA) is adding vinylidene chloride (1,1-dichloroethylene) to the list of chemicals known to the State of California to cause cancer for purposes of the Safe Drinking Water and Toxic Enforcement Act of 1986 (Proposition 65[1]).  

Health and Safety Code section 25249.8(a) incorporates California Labor Code section 6382(b)(1) into Proposition 65.  Regulations describing the process for listing chemicals via the Labor Code are set out in Title 27, Cal. Code of Regs., section 25904.  The law requires that certain substances identified by the International Agency for Research on Cancer (IARC) be listed as known to cause cancer under Proposition 65.  Labor Code section 6382(b)(1) refers to substances identified as human or animal carcinogens by IARC.  An explanation of the carcinogenicity classifications used by IARC, and the Monographs development and peer review by the international working groups of scientific experts convened by IARC, may be found at the following URL: (IARC Preamble).

The basis for the listing of vinylidene chloride (1,1-dichloroethylene) was described in a public notice published in the September 22, 2017, issue of the California Regulatory Notice Register (Register 2017, No. 38-Z).  The title of the notice was “Notice of Intent to List A Chemical by the Labor Code Mechanism: Vinylidene Chloride.”  The publication of the notice initiated a 45-day public comment period.  We received no comments on the notice of intent to list.

A complete, updated Proposition 65 list is published elsewhere in this issue of the California Regulatory Notice Register and is available on the OEHHA website at




Listing Mechanism*

Vinylidene chloride





*Listing mechanism:  LC – “Labor Code” mechanism (Health and Safety Code section 25249.8(a) and Title 27 Cal. Code of Regs. section 25904)

Footnotes and References

[1]  Health and Safety Code, section 25249.5,et seq.