Over 100,000 cases have been brought against Monsanto Corp. nationwide, claiming its Roundup™ weed-killer contains a carcinogenic active ingredient, namely, glyphosate. Hundreds of such cases are pending in Pennsylvania alone. But for over 30 years, the U.S. Environmental Protection Agency (EPA) has found evidence of glyphosate’s noncarcinogenicity for humans, and in 2015, the EPA determined “that glyphosate is not likely to be carcinogenic to humans.” See EPA, “Glyphosate,” https://www.epa.gov/ingredients-used-pesticide-products/glyphosate.

This long-held conclusion regarding the noncarcinogenicity of glyphosate informed the EPA’s decision to approve a label for Roundup that omitted any cancer warning. By approving (and reapproving, over decades) Roundup’s label—pursuant to its authority under the Federal Insecticide, Fungicide, and Rodenticide Act, 7 U.S.C. Section 136 et seq. (FIFRA)—the EPA effectively foreclosed litigants from asserting state-law product liability claims against Monsanto based on a purported duty to warn for failing to include a cancer warning on Roundup’s label. This is so because, as the U.S. Court of Appeals for the Third Circuit recently held in Schaffner v. Monsanto, 113 F.4th 364 (3d Cir. 2024), FIFRA expressly preempts any such claims.