A product can be UL recognized or UL listed. I understand that there is some difference between these two things, but I have never had a full and clear explanation of the difference. What is, in fact, the difference?
Products can be given a UL Listing Mark or the can be classified as a UL Recognized component. The simplest way to think about the difference between these two is that a UL Listing Mark is meant for products that are "complete products." Things like appliances or equipment that you could, for example, buy in a store. A UL Recognized Component, on the other hand, is something that is meant for use in some end product. They usually aren't complete products in themselves. And they usually have conditions of acceptability that dictate how they can be used in end products. Examples of UL recognized components might be a plastic material or an electric motor.
Let's say I'm an appliance manufacturer. And let's say I am designing a new washing machine. If I want my washing machine to be UL listed, I can use UL Recognized Components in my design and this will prevent UL from having to evaluate the safety and construction of the components of my washing machine.
The symbols also look different. The UL Listing mark is a "UL" inside a circle, with the word "LISTED" underneath it. The UL Recognized Component mark looks like a backwards "R" followed by a "U".