Identifying UL Marks with Knowledge Drop

Samantha Koch, an Applications Engineer at Anixter talks us through the differences between Listed, Recognized and Classified UL marks.

Identifying UL Marks Video Transcript

Hi, everyone. Thanks for tuning in. My name is Samantha Koch, and I’m an applications engineer here at Anixter.

Today, I’m going to talk about UL and the difference between Listed, Recognized and Classified marks. Underwriters Laboratory, also known at UL, was founded in 1894 as a nonprofit organization that participates in safety analysis and the development of standards. UL provides safety certification, validation and inspection to manufacturers, regulators, retailers and consumers.

Currently, there are over 20 billion UL marks on products worldwide. There are various UL markings. The three marks I’m going to talk about today are Listed, Recognized and Classified. OEMs should be familiar with all three marks, while consumers see more Listed and Classified marks.

The UL Listed mark on a product means that UL has tested and evaluated a manufacturer’s product and has determined it meets UL’s requirements. The mark also means that an individual product is part of the UL follow-up program. The UL mark consists of four elements:

  • UL mark
  • The word “Listed”
  • Company name and file number
  • Control number


In wire and cable, Listed types can be used for stand-alone products THHN and conduit.

The UL Recognized mark or the Component Recognized mark is used only on components that are part of a product that will be tested by UL. A good way to think of a Recognized Mark is as factory installed because these components are not sold directly to end-users and are installed in a product in a factory. Recognized components are used in Listed products. Common wire and cable components that are recognized are cable ties.

The UL Classified mark is used on systems that UL has tested and evaluated but meet UL requirements only under specified conditions, such as limited, hazardous environments.
This mark, typically consists of four elements:

  • The UL mark
  • The word “Classified”
  • Company name and file number
  • Control number



Common wire and cable products that are classified are fire-resistive cables in a fire-resistive system.

Listed, Recognized and Classified follow the same nomenclature when specifying the country that UL’s tested and validated for. The standards marks are tested for the United States. When the standard mark contains a C, the mark is for Canada. When the mark contains both a C and US, then the item meets requirements for both the United States and Canada.


Many users of the UL mark commonly refer to the marks as UL approved; however, this is inaccurate. UL does not approve everything. The word itself refers to a wide range of acceptance, such as quality, appliances, duration, but UL only tests for safety. It is important to use the correct terminology when referring to a UL mark, such as Listed, Classified or Recognized.

For more information on UL listings, contact your local Anixter representative. Thank you.