Why are empty fuel trucks considered dangerous?

Empty fuel trucks are considered dangerous primarily due to the presence of residual vapors. Even when the tank appears empty, there can still be flammable vapors lingering inside, which can explode upon contact with an ignition source. This is especially concerning because the absence of a liquid fuel does not eliminate the risk; in fact, these vapors can be highly concentrated and pose a significant hazard if proper safety measures are not observed.

Furthermore, while empty trucks may not contain liquid fuel, the potential for overwhelming vapor buildup means that adequate ventilation and safety protocols must be in place during transport and maintenance. Understanding the risk associated with these residual vapors is crucial for ensuring safety in the handling and transportation of fuel trucks.