Which option describes a condition under which a ladder should not be used?

A ladder should never be used if it is defective, as this poses significant safety risks. A defective ladder can have structural weaknesses, such as broken rungs, damaged side rails, or faulty locking mechanisms, which could lead to falls, injuries, or even fatalities. Ensuring that equipment is in proper working order is crucial for maintaining a safe working environment, and using a ladder that is not in sound condition violates safety protocols.

While a ladder being too short, set on soft ground, or dirty may present hazard concerns, they do not inherently indicate a failure of the ladder itself. For example, a ladder that is too short can lead to overreaching, which increases the risk of a fall, but it can be avoided by selecting a proper ladder length for the task at hand. Setting a ladder on soft ground might cause instability, yet it can often be remedied by placing the ladder on firm footing. A dirty ladder could hinder grip but does not compromise its structural integrity. In contrast, using a defective ladder is unequivocally dangerous and must always be avoided.