Deaths from falls top Occupational Safety and Health Administration's (OSHA) "Fatal Four" list for construction. In fact, 364 out of 937 total construction deaths in 2015 were caused by falls. In November of 2016, just prior to the publication of this second edition, OSHA issued a revised rule on fall protection and walking–working surfaces for general industry. Performance criteria and practices for fall protection means such as guardrails, handrails, stair rails, safety nets, ladder safety systems, and so on, are covered in 29 CFR § 1910.29. A fall-arrest system is required if any risk exists that a worker may fall from an elevated position; as a general rule, the fall-arrest system should be used any time a working height of six feet or more is reached. When the worker leans back, the system is activated; however, the personal positioning system is not specifically designed for fall-arrest purposes.