Do Underwriters Laboratories and other recognized testing labs "approve" products?

Underwriters Laboratories (UL) and similar recognized testing laboratories do not grant official approval for products in the sense that they assert a blanket endorsement for their use. Instead, these organizations test products to see if they meet specific safety standards and then issue a listing or certification indicating compliance with those standards. This means that while a product may be listed as meeting certain criteria—such as safety or performance—whether it can be used in a particular installation is determined by the Authority Having Jurisdiction (AHJ). The AHJ is responsible for enforcing codes and standards and has the final say on whether a product can be used in specific applications, which encompasses factors beyond basic safety compliance, including installation practices, local code requirements, and the context of the project's intended use.

Recognizing this distinction helps understand the role of testing labs versus regulatory and enforcement bodies in the installation and use of electrical products.