Which of the following is NOT a common toxicity class of pesticides?

Pesticides are generally categorized into various toxicity classes to help indicate their potential harm to humans and the environment. The commonly recognized toxicity classes include Class I, Class II, and Class III. These classes are based on the acute toxicity of the substances, with Class I being highly toxic, Class II being moderately toxic, and Class III being slightly toxic.

Class IV is also recognized in many classifications as "practically non-toxic." However, Class V does not exist in this conventional taxonomy of pesticide toxicity classes. Thus, identifying Class V as not a common toxicity class of pesticides highlights its absence in the standard classifications used to inform applicators about the safety and risk associated with pesticide use. Understanding these toxicity classes is crucial for safe pesticide handling and application, making it essential for applicators to be aware of which classes exist and how they inform safety protocols.