This is a department rule in addition to the requirements in 29 CFR 1910.176: Conveyor systems passing through more than one room, or from one working level to another, shall be provided in each room, or working level, where exposed to contact, with means to disconnect the power.
Wis. Admin. Code Department of Safety and Professional Services SPS 332.32
Storage of incompatible materials is regulated by NFPA 1, as established by the National Fire Protection Association and adopted in chapter SPS 314.