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What is UL Listed?

What is UL Listed?


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In 1894, William Henry Merrill founded Underwriters Laboratories, Inc., and many industries have been made significantly safer due to his efforts. Merrill was a 25-year-old electrical engineer when he attended the Palace of Electricity at the World's Fair. Perceiving that the field of electricity had a dynamic future, he founded Underwriter's Laboratories, or UL, and proceeded to develop standardized guidelines for the safety of electrical equipment, the testing of it and the elimination of any inherent hazards.

During this time, Merrill also served as secretary-treasurer of the National Fire Protection Association. Subsequently, UL published its first guideline for safety, Tin Clad Fire Doors, in 1903. In 1904, UL applied its label to a fire extinguisher and established a procedure for maintaining the safety of products that require regular maintenance, such as fire extinguishers and other fire safety products. Thus, the onset of Underwriter's Laboratories' expansion that has made thousands of products safer for consumers and professionals.

Anyone who has seen the Underwriter's Laboratories label has at one time or another probably wondered what is the UL listed label for and what is its significance? The scope of what is UL listed runs the gamut from extension cords to hydraulics on a fire engine.

When an electrical product, a fire protection system or other product receives approval to use the UL label, it means that the product or system has undergone extensive safety testing to ensure that it is properly constructed, safe to use and not likely to present a fire hazard.

Of particular importance to the fire protection industry, the UL listed label is applied to all types of safety equipment including gloves, footwear, helmets and protective gear that would cost the lives of firefighters if it were to malfunction. Although these items are not electrical, they are inspected for structural integrity, leaks, burn protection and more.

Additionally, Underwriter's Laboratories tests fire hoses for durability, thread count, leakage and ruptures. Hydraulic equipment is tested for timing and drift and the hydraulic fluid is tested for viscosity, water and particle content.

A fire sprinkler company can request that UL test its fire sprinklers to ensure they are safely constructed and operational. This request can be made online directly to UL and sample tags can be ordered at the same time. There are exclusions to the scope of the UL test for fire sprinklers, for example sprinklers manufactured before 1920 cannot be tested, but UL will supply a comprehensive report of the test results. 

UL provides testing for reliability and safety certification for all aspects of the fire sprinkler industry, whether for manufacturers, consumers, regulatory agencies or insurance companies. The importance of a safe and functional fire protection system cannot be overemphasized. Due to the standards established by Underwriter's Laboratories, Inc., consumers can be assured that sprinklers installed by a fire sprinkler company will be reliable and safe.