UL 325

UL 325 is the Underwriters Laboratories standard titled "Standard for Door, Drapery, Gate, Louver, and Shutter Operators and Systems." It is the primary U.S. safety standard for power-operated garage doors and gates. Openers that meet UL 325 requirements are "Listed" by UL, and most local building codes require Listed equipment for residential installations.

The 1993 revision of UL 325 was a turning point for residential garage door safety. Following a series of child entrapment deaths, that revision mandated that all residential operators include an external entrapment protection device—specifically requiring a photo-eye sensor system (or an equivalent monitored device) that reverses the door if anything breaks the beam during closing. At the same time, UL 325 set maximum closing force and reversal requirements for the operator's built-in force limiting.

UL 325 covers residential, commercial, and industrial operators under different sections. Commercial operator requirements—addressed in sections covering high-cycle, high-speed, and barrier-style doors—typically require more robust entrapment protection combinations, including sensing edges in addition to photo-eye sensors. The standard also sets requirements for emergency operation, radio control security, and backup power.

UL revises UL 325 periodically. Significant amendments have addressed rolling-code requirements for radio controls, battery backup provisions (later adopted as code in California), and requirements for jackshaft-style operators. When specifying a replacement opener, verifying that it is UL 325 Listed ensures it meets current safety requirements and is eligible for installation under local permit.