Which is a recommended safety rule when operating pneumatic lifting bags?

Using solid pieces of plywood is a recommended safety rule when operating pneumatic lifting bags. This practice serves multiple purposes: it distributes the load more evenly and provides a stable base for the lifting bags. Additionally, plywood can protect the airbag from sharp edges or debris that could puncture it, which is crucial in ensuring the safety and longevity of the equipment.

When using pneumatic lifting bags, the safety of both the operator and the victims being rescued is paramount. The combination of strong, stable surfaces like plywood helps maintain a secure lifting environment, minimizing the risk of bag failure or sudden load shifting.

The other options involve practices that could lead to dangerous situations. For instance, inflating the bags quickly can create instability and increase the risk of the load shifting unexpectedly. Working under a load supported only by bags can be hazardous, as bags can fail without warning under significant weight. Stacking airbags three high is generally not recommended due to stability challenges and the increased risk of bag failure or collapse.