The transfer of liquid into containers mounted on vehicles shall NOT take place ____________ but shall be permitted under a weather shelter or canopy.

The correct answer highlights the safety protocols associated with transferring liquid propane into containers mounted on vehicles. This process must never take place within a building due to the inherent risks of flammable gas accumulation and potential ignition sources present indoors. By conducting the transfer outside and preferably under a weather shelter or canopy, it ensures adequate ventilation and minimizes the risk of explosion or fire, thereby prioritizing safety.

Conducting such transfers within a building could lead to dangerous situations, as propane vapor is heavier than air and can accumulate, creating an explosive environment. Therefore, the safety regulations strictly prohibit this practice in enclosed spaces to protect personnel and property.

While transferring liquid propane outside in open air or under a canopy is acceptable, doing so near water sources is typically governed by specific regulations concerning environmental safety and containment. Although transferring propane under an umbrella may provide physical coverage, it does not meet safety regulations required for flammable materials, as it could easily be blown away or fail to provide adequate protection from environmental factors.