EPA issued new guidance on Aug. 9 to registrants of pesticide products containing the active ingredient glyphosate (available here). The guidance aims to clarify required and allowed labeling for pesticide products containing glyphosate in light of the inconsistencies between requirements under the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA) and the State of California’s Proposition 65.

FIFRA broadly governs the registration, manufacture, sale and distribution of pesticide products in the United States, and places very strict and specific labeling requirements on all such pesticide products. All registrants are required to obtain EPA approval for pesticide product labels as part of the product registration process (as well as for certain subsequent amendments to the product registration and/or label). Even minor inconsistencies between the EPA-approved label and a product label found in the marketplace can result in significant “misbranding” civil penalties exceeding six-figures (leading to the expression that the “label is the law” under FIFRA).

FIFRA also provides EPA with widespread powers to determine the safety of pesticide products and their proposed uses. EPA has used these powers to require extensive studies of the potential health effects from exposure to pesticide products containing glyphosate. Based on these studies and its independent evaluation of available data, EPA has concluded that glyphosate is “not likely to be carcinogenic to humans.” Accordingly, EPA has not required glyphosate labels to include warnings that glyphosate may cause cancer in humans.

In contrast, on July 2, 2017, the State of California listed glyphosate as a substance under Proposition 65 based on the International Agency for Research on Cancer’s (IARC’s) classification of glyphosate as “probably carcinogenic to humans.” Because Proposition 65 requires products containing listed substances to include one or more label warnings about such substances being “known” to the State of California to cause cancer, the listing of glyphosate under Proposition 65 created an obvious conflict between federal law (i.e., FIFRA) and California law (i.e., Proposition 65). Given the size of California’s market (and the potential for huge penalties, fines and expenses for potential violations of California’s Proposition 65), many registrants moved to amend their pesticide product labeling to include Proposition 65 warnings).

EPA’s new guidance is a strong rebuke of California’s decision to list glyphosate under Proposition 65 and directly challenges the science relied upon by California (and the IARC) in reaching their conclusions about the carcinogenicity of glyphosate. As such, EPA is requiring all registrants with glyphosate products currently bearing Proposition 65 warning language to submit draft amended labeling that removes such language within 90 days.