UL: Underwriters Laboratories, Inc., Northbrook, IL.
UL Label: An identification label or seal affixed to a roofing product or package with the authorization of Underwriters Laboratories, Inc. The presence of the label indicates that the product has met certain performance criteria.
Ultraviolet (UV): Invisible light radiation, adjacent to the violet end of the visible spectrum, with wavelengths from about 200 to 400 nm (nanometers).
Underwriters Laboratories, Inc. (UL): An organization that provides safety-related certification, validation, testing, inspection, auditing, advising and training services to a wide range of clients, including manufacturers, retailers, policymakers, regulators, service companies, and consumers.
Uplift: See Wind Uplift.
