Glyphosate Facts

Transparency on safety aspects and use of glyphosate-containing herbicides in Europe


Prop 65 list: OEHHA ignores its own scientific assessment

On 26 June, the Office of Environmental Health Hazard Assessment (OEHHA) of California announced that glyphosate will be added to the list of chemicals known to cause cancer for purposes of Proposition 65.

Proposition 65 (Prop 65) is a right-to-know law that California voters approved in 1986. “The law requires that certain substances identified by the International Agency for Research on Cancer (IARC) be listed as known to cause cancer” (OEHHA). It does not ban or restrict the use of listed chemicals. Instead, it requires businesses to provide warnings on listed chemicals prior to a “significant exposure.” These substances include those in IARC groups 1, 2a and 2b. These warnings can be provided in a variety of ways, including on product labels or on signs near where the exposure can occur. The listing of a chemical under Prop 65 does not automatically mean that a consumer warning will be required.

The automatic inclusion is based on IARC’s flawed classification of glyphosate and is in direct conflict with OEHHA’s own scientific assessment. The OEHHA scientific assessment agreed with the conclusions of the U.S. Environmental Protection Agency (EPA), the European Chemicals Agency (ECHA), and other regulatory bodies around the world that glyphosate is not carcinogenic.

The Glyphosate Task Force brings into question the basis of the OEHHA decision as it:

Most importantly, it has been recently shown that the IARC final classification did not consider relevant data proving that glyphosate is not carcinogenic. In fact, the chairman of the IARC committee responsible for glyphosate classification, Dr. Aaron Blair was involved in the decision to not publish important data from a study he participated in (Agriculture Health Study [AHS]) that he later admitted, under oath, would have downgraded IARCs assessment of glyphosate had it been considered. For further info, see  

It is the opinion of the Glyphosate Task Force that OEHHA should have reviewed its decision to automatically add substances under Prop 65 based on IARC classifications until a thorough investigation of IARC funding and working methods has been completed. We are disappointed and surprised that OEHHA has chosen to ignore its own scientific assessment and place glyphosate on the proposition 65 list. We request that glyphosate is removed from the proposition 65 list until a complete review on working and funding methods for IARC has been completed.

Last update: 11 July 2017