A UL fire rating means that the certified building material has been approved by UL for use in construction projects. UL is an independent organization that certifies systems, materials and assemblies used for fire-resistant construction for commercial and industrial applications.
UL publishes its building code qualification standards on the Internet with an exhaustive list of compliance requirements for many different types of materials and products. Examples of these materials include flexible metal circuits, armored cables, rigid metal conduits, factory-made air ducts and commercial electric cooking appliances. The comprehensive list of UL-compliant materials and the respective standards to which they must adhere contains 1,306 separate entries as of 2015, including entries for water-based fire extinguishers and an outline of investigation for pump tank extinguishers.
UL's online search tool allows owners of UL-certified products to locate the organization's certification information, which covers UL-compliant construction materials and equipment as well as assemblies and systems designed for commercial and industrial fire-resistance preparedness programs. Web users search for this information either by product name, relevant keyword, master format number or through the related installation code section as provided on the organization's website. For example, UL lists information about leakage-rated doors through the "UL 1784" identifier and information about smoke dampers through the "UL555s" identifier.