Abstract: Since Argentina became the world’s largest consumer of glyphosate, Argentine producers’ lives, livelihoods, and landscapes have become intimately entwined with agrochemicals. This article follows a range of settler-farmers making “common sense” decisions about how to live and farm with agrochemicals in Argentina’s genetically modified (GM) soy belt. In a process I call agrochemical worlding, settler-farmers perspectives about agrochemical safety are informed by long-standing arrangements about who determines how to use Argentine land, thereby shaping how settler-farmers move through a landscape saturated with agrochemicals. Using a progression of ethnographic encounters, I situate and then dislodge a sense of agrochemical safety by attending to enactments of different agrochemical ontologies. Attention to worlding practices at the intersection of settler common sense and toxicity both situates GM farming in Argentina as a form of settler agriculture, and agrochemical use as a contemporary technique of settler colonialism.