A. According to the EPA a pesticide is defined as the following:
“A pesticide is any substance or mixture of substances intended for: Preventing, destroying, repelling, or mitigating any pest. Though often misunderstood to refer only to insecticides, the term pesticide also applies to herbicides, fungicides, and various other substances used to control pests. Under United States law, a pesticide is also any substance or mixture of substances intended for use as a plant regulator, defoliant, or desiccant.”
– USEPA
As you can see, this is a very broad definition and applies to many more commonly used materials than most people believe.