They are not intended to be used as ladders, walk ways or support for people as this can cause personal injury and also damage the system and any installed cables. * Safe use of these products is best ensured by installing parts that have been designed and tested together as a. One of the primary cable tray safety hazards is cable damage, which can occur due to improper installation or environmental factors. When cables are improperly routed within the tray, they may face undue pressure or friction. The NEC provides specific and more detailed requirements for cable tray fill. Cable trays can be part of a planned cable management system to support, route, protect, and provide a pathway for cable systems.