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.

invisible light radiation, adjacent to the violet end of the visible spectrum, with wavelengths from about 200 to 400 nm (nanometres).

invisible light radiation, adjacent to the violet end of the visible spectrum, with wavelengths from about 200 to 400 nm (nanometres).

an asphalt-saturated felt or other sheet material (may be self-adhering) installed between the.

Underwriters Laboratories Inc. (UL) is an independent product safety certification organization. Established in 1894,[1] the company has its headquarters in Northbrook, Illinois.[2] UL develops standards and test procedures for products, materials, components, assemblies, tools and equipment, chiefly dealing with product safety. UL also evaluates and certifies the efficiency of a company’s business processes through its management system registration programs.

The UBC was first published in 1927 by the International Council of Building Officials. It was intended to promote public safety and provided standardized requirements for safe construction which would not vary from city to city as had previously been the case.