In terms of safety, which characteristic is true concerning U.L. tested appliances?

U.L. (Underwriters Laboratories) tested appliances are designed to meet specific safety standards and undergo rigorous testing to ensure they operate safely under normal conditions. Saying that they reduce operational hazards means that these appliances are engineered to minimize risks, such as fire hazards or the potential for harmful emissions, when used as intended.

While U.L. testing significantly enhances the safety of appliances, it is important to understand that no appliance can be deemed completely failure-proof. They can still experience mechanical failures, improper use, or unforeseen issues. Similarly, while U.L. tested appliances are designed to mitigate the risk of backdrafting, it is not accurate to claim that they are entirely incapable of it under all circumstances. Regulatory compliance does not eliminate the need for regular maintenance either; even the safest appliances require routine checks to ensure they are operating correctly and safely over time.