Use UL-Listed Devices

Model house with power Cord
Getty Images/Tony Cordoza

When you’re out shopping for electrical devices and supplies for your home project, UL listing is the best way to ensure you’re getting safe, properly designed and manufactured products. A product that bears the stamp of UL listing has been tested and verified that it meets UL standards for safety. So, what is UL, and what does UL listing mean? 

A Testing Laboratory by Any Other Name

UL is formerly, and perhaps most commonly, known as Underwriters Laboratories.

Doesn’t exactly leap off the tongue. Perhaps that’s why the organization has dropped the full name in favor of the well-known abbreviation. Works for me. UL is the leading nationally recognized testing authority in the U.S. They also test Canadian products.

UL testing makes sure that wire sizes are correct, devices can handle the amount of current they say they can, and products are constructed correctly to provide safe function in your home. For over a hundred years, this non-profit organization has developed more than 1,000 standards for safety. The UL website is a good place to learn more about the organization and what they do.

How UL Listing Works

It’s pretty simple: reputable manufacturers submit their products for UL testing. If a product passes the test, the manufacturer is allowed to stamp the product with an official UL mark. Look on the back of any quality switch, outlet, light bulb and other electrical essentials and you’ll see the mark.

Submitting for testing is voluntary, but because most electrical codes require UL-listed products when available, manufacturers have plenty of incentive to get their products listed. Not all products can be or have to be, listed. For some products there are no applicable UL standards; for others, the products simply aren’t safe enough to ever be listed.

That’s why it’s impossible to find a vinyl dryer vent hose with UL listing; they’re simply not safe.

Why It's Worth Checking

For the consumer, checking for the UL mark is an easy way to separate the decent stuff from the junk. If you're comparing two similar light switches and notice that one carries the UL mark while the other doesn't, you should ask of the latter, why not? Chances are it's a cheap import that wouldn't meet UL standards even if the manufacturer cared enough to submit it for testing. To make this decision easier still, the National Electrical Code (NEC), requires the use of UL listed products when available. In other words, if there are UL-listed products in a given category, you can’t use a product from that category that is not listed. Code wording often refers to qualifying products as “listed.” This generally means UL listing, although there are other nationally recognized testing laboratories, such as Intertek and CSA Group (in Canada).