Underwriters Laboratories (UL) standards are voluntary standards created to establish minimum requirements to evaluate products in the interest of public safety. UL is a not-for profit organization that strives to “promote safe, secure and sustainable living and working environments for people by the application of science, hazard-based safety engineering and data acumen.”

With over 1,500 UL standards, there’s a lot of information to comb through. For the purposes of this blog, we’ll be focusing on one of the standards that makes a huge impact on the commercial door industry: UL 325.

The UL 325 standard applies to electrical and pneumatic door and gate systems, and door, drapery, gate, louver, window and turnstile operators, together with controls and accessories for use with such operators. It was put in place to prevent entrapment accidents and reduce their risk. The gate operators this standard encompasses are put into four categories by UL, covering a range of residential, commercial, industrial and guarded industrial applications.

UL 325 also outlines safety improvements for automatically operated gates, including:

• Inherent entrapment protection system that stops and reverses the gate within 2 seconds.
• A non-contact photoelectric sensor or the equivalent that stops or reverses the gate within 2 seconds.
• A contact sensor (edge device or the equivalent) that stops and reverses the gate within 2 seconds.
• An inherent adjustable clutch or pressure relief device that, upon sensing an obstruction in any direction, will stop the gate and not result in a closing force more than 10 percent higher than the initial setting required to stop the gate, which cannot exceed 40 lbf (pounds of force).
• An actuating device requiring continuous pressure to maintain opening or closing motion of the gate. Upon removal of pressure, movement of the gate must cease.
• An audio alarm.

What Other Factors Should I Consider for UL 325 Compliance?

You first want to consider distance. If your operator is closer than eight feet to the rolling door, all pinch points must be covered. Typically, the operator’s manufacturer will supply covers for any exposed moving parts.

Another factor to consider with UL 325 compliance is how the automated operator closes your door or gate. When installing an operator for UL 325 compliance, you have a few options:

 Option 1:

An operator that uses constant pressure to cycle through opening and closing your door, gate, or grille. This also means your closure of choice must be monitored or use a primary entrapment protection device. In the monitored version, someone has to manually control the closure’s cycling from a control station where the door, gate, or grille can easily be seen.

Option 2:

An operator that uses a sensing device such as sensing edges, photo eyes, and light curtains. Sensing edges are activated when the door’s bottom bar touches any object in the door’s closing path, and thus require contact to work properly. Light curtains and photo eyes do not require contact for door cycling. You can learn more about all three in our "Non Contact Vs. Contact Safety Devices for Rolling Applications" blog here.

The UL 325 standard gets even more specific with your closure’s cycling devices, depending on their levels of entrapment protection. A primary entrapment protection device controls the closure with the push of a button. Examples of these include photo eyes, wireless sensing edges, and ELR electric sensing edges. Secondary entrapment devices can be used in conjunction with a set of primary entrapment photo eyes or with a constant pressure to close operation. Examples of secondary entrapment protection devices include non-monitored photo eyes, sensing or smoke seal edges, and electric sensing edges with wireless edge kits.

See below for more details on entrapment protection devices.

How Does UL 325 Compliance Make a Difference?

UL 325 compliance can make a significant difference for everyone’s safety and reputation. This standard was created in response to entrapment accidents with automatically operated gates that resulted in injuries and deaths, so complying with this standard helps keep people safe from motor-driven operators.

Whether the operator and closure are in residential or industrial areas, safety should be everyone’s top priority. Meeting UL 325 compliance is also a reputation and liability saver. From designers and specifiers to dealers and technicians, along with end users, everyone can rest easy knowing the closures and operators they choose can help save lives by following UL 325.

If you have any questions about the UL 325 standard or which products can help you achieve compliance, feel free to reach out to our ADS team at 885.982.2022.

Cookson continues to lead in innovations in roll up door, security gate and closure products. To inquire how Cookson’s experts and customer service can help you with your next roll up door project, call 1-800-294-4358