When must a pesticide be re-registered?

The re-registration of a pesticide is primarily tied to regulatory frameworks and safety assessments established under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). A pesticide must undergo re-registration in situations related to its formulation changes, safety data, or environmental impact assessments that have evolved since its initial registration.

While one might think that the lack of FIFRA review would necessitate re-registration, this isn't precisely the case. Rather, all pesticides must be registered under FIFRA before they can be marketed and used, and they are subject to periodic evaluations that ensure they meet current safety standards. Therefore, a pesticide that has gone through FIFRA and has been assessed does not necessarily need to be re-registered simply due to an absence of previous reviews under this act.

In contrast, a new formulation of a pesticide usually requires re-registration to ensure that the new chemical formulation's safety and effectiveness are evaluated. Regular re-registration every five years ensures that older pesticides continue to meet current safety and efficacy standards as new data becomes available. Similarly, incidents of misuse could prompt a review or necessitate changes in registration, but they do not directly dictate a requirement for re-registration.

Overall, the correct answer highlights a misconception about the regulatory requirements, as