UL is English Underwriters Laboratories (Underwriter Laboratories Inc.) or UL; it can be firm and safety signs, safety standard.UL test is the most authoritative, is also engaged in safety testing and identification of the larger non-governmental organizations. It is an independent, non-profit, professional do the test for the public safety agencies. It uses scientific test method to study a variety of materials, devices, products, equipment, construction of life, property damage and the extent of the harm; sure, write, and issue the corresponding standards and help to reduce and prevent the loss of life and property caused by the data at the same time. Carry out the truth research business. It is mainly engaged in product safety certification and management of safety certification business, its ultimate goal is to get the market with a security level of commodities, for personal health and property safety is guaranteed. Xian.
CUL is on the basis of UL to increase the CSA (Canada) certification, and access to the United States and Canada, a common security certification mark.