FMC Corporation has submitted the regulatory dossier for rimisoxafen to the United States Environmental Protection Agency (EPA), marking the first global regulatory submission for this herbicide active ingredient. The submission covers use on corn, soybean, sunflower and select pulse crops, addressing intensifying weed resistance pressure in key row crop markets.
Filing the dossier represents a significant milestone for FMC, according to Seva Rostovtsev, executive vice president and chief technology officer at FMC. The company stated that years of innovation and scientific discovery led to this breakthrough dual mode of action technology, designed to help growers facing complex weed resistance challenges.
Discovered at FMC's Stine Research Center, rimisoxafen is built on over a decade of biology research and more than 1,000 field and greenhouse studies. It is the first herbicide active ingredient classified as a dual mode of action by the Global Herbicide Resistance Action Committee (HRAC). Designated under Groups 12 and 32, the ingredient inhibits two distinct biochemical pathways in weeds, which helps delay resistance development compared to single mode of action herbicides.
Herbicide-resistant weeds continue to challenge growers and drive demand for new modes of action. According to a 2025 Weed Science Society of America National Weed Survey, Palmer amaranth and waterhemp rank as the most troublesome broadleaf weeds in U.S. soybean production. In extensive field testing, rimisoxafen has demonstrated consistent activity against both. The U.S. represents a critical market for next-generation weed control solutions with more than 70 million hectares of corn and soybeans grown annually and growers spending more than $6 billion annually on weed control.
Rimisoxafen is the third novel herbicide active ingredient FMC has advanced to regulatory submission in recent years, following Isoflex active and Dodhylex active. FMC intends to pursue regulatory submissions for rimisoxafen in additional key geographies and crop segments as part of its global development program. Timing and outcomes are subject to regulatory review and approval in each jurisdiction. Rimisoxafen is not currently registered for sale or use in the United States or any other country.