For consumers, UL is the symbol of safety signs, and globally, UL is one of the manufacturers' most trusted qualified assessment providers.UL is mainly engaged in product safety certification and operation safety certification business, whose ultimate goal is to obtain a fairly safe level of products for the market and contribute to the guarantee of personal health and property safety. As far as product safety certification is concerned, as an effective means to eliminate the technical barriers to international trade, UL also plays an active role in promoting the development of international trade. UL was founded in 1894, and in the initial stage, UL maintained its operations mainly through fire insurance departments, and it was not until 1916 that UL became fully independent. After nearly a hundred years of development, UL has become a world-renowned certification body, which has a full set of strict organizational management system, standard development and product certification procedures.