what is ul rating
UL RATINGS. UL stands for Underwriters Laboratories, an independent organization dedicated to educating businesses and the public about safety and performance of products in a wide spectrum of industries.UL has been testing and rating products for more than 100 years, and evaluates nearly 20,000 products annually.The UL rating is an indicator of product quality and certification of safety.or example, the UL Class 350 1-hour fire rating means that the internal temperature of the safe will not exceed 350Â°F for at least 1 hour when exposed to external temperatures over 1700Â°F. A safe may have a 1-, 2-, or 3-hour time classification.