Taking an organizational sociology approach, the study of French pesticide regulation highlights the role of the unexpected effects of secrecies in organized ignorance. It demonstrates that the main regulator, the French food safety agency (ANSES), as well as the users of pesticides, the farmers, develop their own subcultures of secrecy to conceal information about their real practices. These subcultures support each other tacitly: the opacity created by farmers around their practices stifle knowledge production and reporting on their exposure to pesticides. Consequently, the risk standards are never called into question, which ensures that the French food safety agency maintains its scientific reputation. In turn, the fact that official standardization of risk is never challenged, impedes the reinforcement of pesticide regulations that would otherwise hamper day-to-day crop management. This tacit agreement between these combined subcultures maintains the illusion that the regulatory science used for risk management could control a broad spectrum of hazards, when in fact it has only a limited or even outdated knowledge of them. This deepens the definitions of organized ignorance. It demonstrates that non-knowledge production results not only from the complex mix of political, scientific and regulatory frameworks surrounding official expertise as STS researches tend to show, but also from more widespread and less perceptible sociological mechanism such as tacit understanding. Unexpected effects of intentional actions also count as much as willful actions in strategic ignorance production.