Portable containers shall not be filled while located in which of the following areas?

Filling portable containers in the trunk of a vehicle is considered unsafe due to several critical reasons. The trunk of a vehicle is generally a confined space with limited ventilation, which can lead to the accumulation of flammable vapors when filling the container. If any spark or ignition source is present, it could result in a fire or explosion. Additionally, transporting flammable liquids can complicate emergency response and pose risks to both drivers and those near the vehicle.

In contrast, filling portable containers in other listed areas, such as inside a building, on the ground, or on a workbench, can often involve greater control over environmental factors. When performed indoors, it is typically under strict regulations that ensure adequate ventilation and the implementation of safety measures. On the ground or a workbench usually allows for better supervision and handling of spills and leaks, further reducing the risk of fire hazards associated with filling flammable containers.