UL is a non-profit organization chartered to establish, maintain and operate laboratories for the examination and testing of devices, systems, and materials. While UL's primary function is to conduct tests on products to determine if they are hazardous to life or property, they have established a number of UL standards. UL performs the tests specified in standards set by others, such as the National Fire Protection Agency (NFPA), and authors of the National Electrical Code (NEC).
Cable Standards
UL Standard 13 - PLTC
UL Standard 4 - Armored Cable
UL Standard 62 - Flexible Cord
UL Standard 44 - Rubber-Thermoset
UL Standard 83 - Thermoplastic Insulated
UL Standard 719 - Non-metallic
The UL labels of approval, detailed below, are recognized and respected by electrical inspectors, fire marshals, insurance underwriters, and regulatory personnel.
UL Listed
To be labeled UL Listed, a product must successfully complete a series of mechanical, electrical and thermal characteristic tests which simulate all reasonable, foreseeable hazards. A UL Listing is assigned exclusively for the specific application for which it was tested and is not valid for other applications.
UL Classified
For UL Classified labels, products are evaluated with respect to one or more of the following:
The UL "Classified" rating is generally restricted to industrial or commercial products.
UL Recognized
Products bearing UL Recognized labels have been tested for use as a component in a UL Listed package. These component products are tested for electrical, mechanical and thermal characteristics.
UL Recognized is a more general purpose approval than UL Listing in that it allows a product to be certified for a category of equipment uses. An example is hookup wire, which has been UL Recognized as appliance wiring material, a category of uses that includes data communications, telecommunications, and instrumentation.