There are several types of UL Marks, described below. Each has its own specific meaning and significance. The only way to determine if a product has been certified by UL is to look for the UL Mark on the product itself. In a few instances, the UL Mark may be present only on the packaging of a product.

Some products certified by UL are components that are intended to be used in the manufacture of a complete Listed product. These components cannot bear the UL symbol, but may use a special Recognized Component Mark.

The UL Mark on a product means that UL has tested and evaluated representative samples of that product and determined that they meet UL's requirements. Under a variety of our programs, products are periodically checked by UL at the manufacturing facility to make sure they continue to meet UL requirements.

The UL Marks may be only used on or in connection with products certified by UL and under the terms of written agreement with UL.

In addition to these marks, UL also provides access to the marks required in a number of other key world markets.