A product with Underwriters Laboratories approval is said to be "UL-rated." Purchasers can identify such products by the distinctive UL symbol, accompanied by a serial number.
UL has ratings standards for many products, even bullet-proof vests. The average householder may be more familiar with UL-rated products such as home electrical appliances.
A moderately famous video clip shows UL researchers demonstrating the risks of certain models of deep-fat turkey fryer. This serves as a -- perhaps overly dramatic -- suggestion of the importance of this sort of product testing.