Which item is NOT required to be kept on a service vehicle transporting pesticides?

The item that is not required to be kept on a service vehicle transporting pesticides is a backflow preventer. This is because backflow preventers are typically installed in plumbing systems to prevent the reverse flow of contaminated water into clean water supplies, and their relevance is more associated with stationary equipment and installations rather than transport vehicles.

On the other hand, having a first aid kit is important for emergency situations involving pesticide exposure or accidents, ensuring immediate care is accessible. A list of stored pesticides is crucial for inventory management, safety, and compliance with regulations, allowing for proper handling and understanding of the chemicals being transported. A spill kit is vital as it enables quick response to any accidental pesticide spills, protecting both human health and the environment. Each of these items is directly related to safety and regulatory compliance in the context of pesticide transportation.