 Since most power entry modules connect to the AC powerline, they are subject to safety standards set by Underwriters Laboratories (UL), the Canadian Standards Association (CSA), Verband der Elektrotechnik, Elektronik und Informationstechnik (VDE), and many other safety standards agencies such as the BSI Group (BSI).Power entry module manufacturers take on the responsibility of producing power entry module products in such a way that they meet the standards of one or more of these safety standard agencies, so that equipment manufacturers using them need not take responsibility for the internal details of safety certification.Power entry module manufacturers also pay independent testing labs to test their products against the safety standards, so that the products can carry the safety agency’s approval mark.