If personnel cannot see their feet, they should take preventative measures if they are how far off the ground?

When personnel cannot see their feet, it is crucial to take preventative measures, particularly when they are at least 6 feet off the ground. This is because the risk of falling increases significantly at this height, leading to serious injuries. The standard emphasizes the need for safety awareness and the use of appropriate fall protection measures as one ascends to heights where visibility is limited. This height of 6 feet serves as a metric for evaluating when additional precautions are necessary, as falls from this height can lead to greater consequences. Therefore, understanding the importance of visibility and the corresponding safety practices at this height is essential for maintaining workplace safety in elevated environments.