Underwriters Laboratories (UL) is the largest and best known independent, not-for-profit testing laboratory in the world. Based in Northwood, Illinois, UL conducts safety and quality tests on a broad range of products, from fire doors to CCTV cameras. The laboratory provides a full spectrum of conformity and quality assessment services to manufacturers and other organizations. It also assists jurisdictional and provincial authorities, offers educational materials to consumers, and works to strengthen safety systems around the world.

UL provides comprehensive diagnostic testing services in the following areas: fire testing; medical device testing; EPH services (food service equipment, drinking water certification, plumbing equipment); audio/video; home electronics; Source Verification and Inspection Services (SVIS); electric vehicle components and systems; EMC testing and certification; information technology equipment (ITE) industry services; and telecom industry services. It conducts tests on products in these areas to see whether they meet standards set by UL engineers in conjunction with input from manufacturers and product users, but it will also test products to see whether they meet standards set by outside entities, such as a city (in the case of building codes, for instance). In 1999, 16.1 billion products and components received passing grades from the laboratory's 35 facilities, which are located around the world.

In addition to its work in the U.S. market, Under-writers Laboratories maintains services for companies looking to test products for international markets. This division of UL studies international product certification standards, assists clients with the application process, helps with correspondence and translation, and can coordinate the exchange and review of test data. In order to increase its efficiency in these international realms, Underwriters Laboratories has also launched a sustained effort to establish common standards for safety requirements, testing protocols, and certifications around the world. The impetus for this effort, according to UL, is a recognition that companies seeking to establish a presence in multiple overseas markets sometimes need as many as 20 separate safety certifications for a single product, a requirement that "can cost as much as $8,000 per safety mark per product. Many companies have annual certification budgets of $5 million or more." UL hopes to first establish common standards between the United States and Canada, then turn its attention to other markets.

UL DESIGNATIONS "Underwriters Laboratories, which has been in existence for more than 100 years, is very sensitive to the prevalent but mistaken belief that it approves products," wrote Robert C. Cook in Security Management. "The only entity that can actually approve or reject a product is a federal, state, or local government agency—known generally as the 'Authority Having Jurisdiction' or AHJ." However, an AHJ—whether it is a local health code inspection department or the federal Occupational Safety and Health Administration—often requires products to be tested by Underwriters Laboratories or another lab before the agency will approve its use.

UL hands out one of three different designations to products that pass its tests: UL listed, UL recognized, or UL certified. Businesses should note that there is no such designation as "UL approved"; companies that mistakenly tout their products with such a designation will arouse the ire of Underwriters Laboratories, which will insist that the company clarify the matter immediately.

UL Listed. This designation means that the tested product meets the laboratory's standards and can be used by itself.

UL Recognized. This designation is granted to equipment components that are used in combination with other pieces of equipment to create a finished product.

UL Certified. This designation is used by UL when it has been successfully tested to the standards of an outside authority, such as a city's building code requirements.

In 2000 UL announced its intention to transition to usage of Standard Technical Panels (STPs) in its development of diagnostic processes. The STPs will include representatives from consumer protection organizations (such as the National Consumer League), manufacturers, industry trade associations (like the Association of Home Appliance Manufacturers), and regulatory authorities (including government agencies like the Consumer Product Safety Commission). According to UL, these forums will work together to establish consensus opinions on diagnostic standards and will vote on proposed standards before they are adopted.

Businesses considering enlisting the services of Underwriters Laboratories (or similar labs) should be aware that testing can be both expensive and time-consuming. Bills of several thousand dollars per product tested are not unusual in many industry sectors, and the testing procedures usually take about six months to complete, with some tests extending well beyond that time frame. But the importance of UL acknowledgment is very significant to marketplace image in many industries.


Cook, Robert C. "A Tale of UL Testing." Security Management. July 1995.

Jancsurak, Joe. "New Standards for Standards." Appliance Manufacturer. August 2000.

Strom, Shelly. "Underwriters Laboratories Gives Seal of Approval." Business Journal-Portland. August 4, 2000.

"The Underwriters Labs' Faster Seal of Approval." Business Week. December 20, 1993.

"Underwriters Labs Pursues Single Worldwide Standard." Manufacturing News. August 25, 2000.

Wingo, Walter S. "A Boom Time for Product Testing." Design News. March 9, 1992.

User Contributions:

Comment about this article, ask questions, or add new information about this topic: