Final answer:
Safety nets must be installed no more than 30 feet below the walking/working surface whenever working near an open edge to prevent serious injuries or fatalities in the event of a fall.
Step-by-step explanation:
Safety nets must be installed no more than 30 feet below the walking/working surface whenever working near an open edge. This is to ensure the safety of workers and prevent serious injuries or fatalities in the event of a fall. Safety nets act as a barrier to catch falling workers and equipment, reducing the impact and preventing them from hitting the ground.