There are two types of product certifications in the United States – finished product certifications and
component certifications. It is very important that you know the difference and that you know the
limitations involved with using certified components.
Components that are intended to be used in the manufacturing of other products are usually certified as “components” with “conditions of use” indicating the acceptable application and use criteria for the component. UL refers to the components it certifies as “Recognized Components”. UL Recognized Components are marked with a backwards UR which looks like this:
Listed Products: Finished products are “Listed”. A “Listed” product has all “conditions of use” marked
on the product, the packaging, and/or the instruction manual. A “Listed” product is ready to be installed
Listed Components: There are also some “Listed” components that are Listed because they can be purchased over the counter and are field installed (light switches, wire nuts, j-boxes, fuses, etc.). Listed products bear the certification mark of the US-NRTL that certified the product. Here is an example of UL’s certification mark for “Listed” products and “Listed” components:
Component Application: When using certified components, be aware of the limitations
Listed components have all “conditions of use” marked on the product, the packaging, and/or the instruction manual – make sure you read these. Listed components bear the “Listing” Mark.
- “Recognized Components” have “Conditions of Acceptability” (CofA’s) in their certification report that can
include many special considerations. It is critical that you get the CofA’s for all Recognized Components
you use and make sure you comply with all the conditions specified. There can be conditions of use that
you cannot meet requiring a component change. There can also be conditions requiring specific tests be conducted on the component in the end product.
- Recognized Components are not intended to be field installed – the electrical inspector should not be seeing products with ЯU marks in the field. Do not assemble a bunch of recognized components and
think the assembly is certified – it is not! A Building or Electrical inspector will reject uncertified systems
comprised of Recognized Components. It is the Listing mark that the inspector is looking to see since
only “Listed” products are intended for final installations.
- If you are putting together a bunch of Recognized Components, you should be getting the assembly
“Listed” (or alternatively, “Field Labeled” which is a limited, on-site certification).
*: UL in a circle and the backwards UR marks are registered trademarks of Underwriters Laboratories, Inc.
CertifiGroup operates a complete Product Test & Certification Lab
CertifiGroup can certify or field label your products to UL & CSA standards
On-site, at your facility, or in our lab!