Which of the following is NOT a type of pesticide that can be regulated by FIFRA?

FIFRA, or the Federal Insecticide, Fungicide, and Rodenticide Act, is a federal law that regulates the sale, distribution, and use of pesticides in the United States. Under this act, various types of substances specifically used for pest control, including insecticides, herbicides, and fungicides, are closely monitored to ensure they are safe and effective for their intended purposes.

Fertilizers, on the other hand, are not classified as pesticides. Their primary function is to supply essential nutrients to plants rather than to control pests. While fertilizers play a critical role in agricultural practices, they do not fit within the regulatory scope of FIFRA, which focuses on substances that kill or manage pests. This distinction is pivotal in understanding what FIFRA regulates and the types of substances that fall under its guidelines. Therefore, fertilizers are not subject to the same regulatory framework as those pesticides that directly combat pests or disease, making the correct answer to the question regarding what is not regulated by FIFRA clear.