The engine of a placarded vehicle must be shut off when fueling.

The engine of a placarded vehicle must be shut off when fueling.

• A. True
• B. False
• C. Only when using electric fuel
• D. Only when no one is nearby

Answer: (A)

The main idea is safety during fueling with hazardous materials. When a vehicle carrying hazardous materials is being fueled, turning off the engine is essential because it removes potential ignition sources. An operating engine can generate sparks from electrical components or heat from exhaust, and fuel vapors are highly flammable. By shutting the engine down, you reduce the risk of those ignition sources igniting vapors in the fueling area, helping prevent a fire or explosion. It isn’t about using electric fuel or about whether someone is nearby, and the rule applies specifically to placarded vehicles, so the statement is true.

The main idea is safety during fueling with hazardous materials. When a vehicle carrying hazardous materials is being fueled, turning off the engine is essential because it removes potential ignition sources. An operating engine can generate sparks from electrical components or heat from exhaust, and fuel vapors are highly flammable. By shutting the engine down, you reduce the risk of those ignition sources igniting vapors in the fueling area, helping prevent a fire or explosion. It isn’t about using electric fuel or about whether someone is nearby, and the rule applies specifically to placarded vehicles, so the statement is true.