UL 568 specifies the requirements for nonmetallic cable trays and associated fittings designed for use in accordance with the rules of the Canadian Electrical Code (CEC) Part 1, and the National Electrical Code&174; (NEC).
ANSI/UL 568-2004 history
2004ANSI/UL 568-2004 Standard for Safety for Nonmetallic Cable Tray Systems (proposal dated 1-9-09)