CDL Hazardous Materials Practice Test

Before moving a vehicle loaded with hazardous material, what must be done?

1. Check tire pressure

2. Close all manholes and valves

3. Ensure the fuel is full

4. Inspect mirrors and lights

The correct answer is: Close all manholes and valves

Before moving a vehicle loaded with hazardous material, it is essential to ensure that all manholes and valves are securely closed. This step is crucial because it prevents any potential leaks or spills of hazardous materials, which could pose significant risks to public safety and the environment. Keeping manholes and valves closed maintains the integrity of the containment system, ensuring that no harmful substances escape during transport. This procedure is part of the broader safety protocols that drivers of hazardous material vehicles must follow. Proper closure of manholes and valves is critical in minimizing the risk of exposure to potentially toxic or dangerous materials, which can have severe consequences if released. While checking tire pressure, ensuring the fuel tank is full, and inspecting mirrors and lights are important pre-trip checks for any commercial vehicle, they do not directly address the specific safety concerns associated with transporting hazardous materials. Therefore, closing all manholes and valves takes precedence as an immediate and necessary action to ensure safe transport.