What is a necessary item to carry in a cargo tank vehicle during loading or unloading?

Chock blocks are essential items to have in a cargo tank vehicle during loading or unloading to ensure safety and stability. When a cargo tank vehicle is parked for these operations, especially on an inclined surface or when the vehicle is not on level ground, chock blocks are utilized to prevent the vehicle from rolling. Their primary purpose is to physically block the wheels, providing a secure hold that minimizes the risk of accidents while filling or emptying the tank.

While other safety items like fire extinguishers, safety cones, and reflective triangles are important for broader safety regulations and emergency preparedness, they do not address the specific need to stabilize the vehicle during loading or unloading tasks, which is critical for preventing spills and ensuring the safety of personnel involved in these processes.