The need for UL approvals is actually a common misconception in the industry. Specifically what is needed is an NRTL (National Recognize Test Laboratory) Certified/Listed/Labeled product to a UL standard, not a UL Listing.
UL used to have a monopoly on product safety testing, however after MET was approach by several organizations and agencies MET challenged the monopoly that UL had, and the courts agreed with us. As a result of our lawsuit OSHA created the NRTL program and in 1988 MET became the nation’s first NRTL(Docket Number: NRTL-1-88.
UL now has two separate organizations one which is commissioned by the US government to write the standards that the other which competes against MET LABORATORIES for testing and evaluation to the UL standards.
There are several such Laboratories in place now that offer testing, evaluation and certification to the UL Standards.
To help show that a company’s product meets the UL standards some companies choose to use a mark similar to the one shown above. Unfortunately there are some manuals or guidelines that have not been updated or are not worded properly causing customers to not understand what the actual requirements are(as a result of the NRTL program being created).
Below is an excerpt from the OSHA website which correlates with the information provided above –