Understanding UL April 11, 2001 Gerry Zekowski, Lighting Consultant What is the most successful printed item in the United States? The Bible? No. Dollar bills? No. It's the Underwriters Laboratories (UL) label. Six billion UL labels are printed and affixed each year to products all over the world. UL is in homes and businesses many times over, so how come we know so little about something that is so pervasive? The misinformation abounds, we hear people talk about having "UL approval," but there is no such thing as "UL approval." We hear talk about THE UL LABEL, but there is no such thing as ONE LABEL -- there are several labels, some with very different meanings. Not only are there different meanings, but there is a UL label that appears as an RU with the "R" written backwards. We hear of products that are UL Listed, Certified, Approved, and Recognized as if these terms meant the same thing. They do not, and for those of us in the lighting profession, it is important to know the differences. HOW UL CAME TO BE First, however, some brief history. UL was established in 1894 in Chicago after the great Columbian Exposition saw the world's first mammoth display of electricity. The public witnessed not only the new Edison light bulb, but a rash of fires. The need for testing to insure fire safety became apparent and UL had its birth with start-up costs of $350. The great San Francisco earthquake and subsequent fires that destroyed 90 percent of the city provided a major boost for UL. The insurance companies paid off their obligations, but lost 46 years of profits. In 1907, the insurance companies helped enact revised building codes and by so doing broadened UL's role for the country. As time passed and technology expanded, the need for safety testing in many other areas became apparent. UL tested for the airline industry, for boat safety, non-slip floor waxes, explosives, etc., etc. Technology brings many benefits, but always with the risk of new hazards. To me a UL label is an insurance policy. In many situations I cannot visually determine if a product is safe. Recently, I became aware of a floor lamp that did not have a UL label. The lamp appeared well-made and was produced by a major manufacturer, but it did not have a UL label. I was asked to research the lamp regarding safety and ran some heat tests on it and found that the temperature on the exterior of the bowl exceeded 170 degrees centigrade, 338 F. That's dangerous! Ninety degrees centigrade is the maximum for safety of portable lamps, but how could a consumer or professional determine that condition by visual means? We turned the product back to the manufacturer for redesign and Listing by UL. The UL label means to me that someone, more qualified than I, evaluated samples of a product for safety and, therefore, both my client and I should feel safe, and secure in knowing we did our best. To say that a product is "UL approved" is incorrect. UL does not approve anything; the word "approval" implies a wide range of acceptance, and UL only tests for safety -- not quality, durability, application, etc. LISTING VERSUS CLASSIFIED The classic UL label indicates that UL tested samples of a complete and total product and LISTED the product because it passed their safety tests. The presence of the listing label, what the UL calls the listing mark, also means that the individual product was manufactured under the UL's follow-up services program. Therefore, the correct terminology is to say that the product is listed. UL avoids saying a product is "approved," as they know that is the responsibility of the local governmental inspection authorities. A complete listing mark consists of four elements: the UL Mark, the word "Listed," the product identity, and the control number. The UL Mark can be separated from the other parts: it can be printed on the manufacturer's label, or stamped into the product. However, all four label components are required. There is another type of label that has the UL Mark with the word "classified" over it. That label indicates that samples of the product were evaluated for certain types of uses only. The UL Mark, along with a statement on the hazards or conditions tested for, must be permanently affixed to the product. The statement allows the field inspection authorities to determine if the product is going to be put to the use for which the product was evaluated. The RU, with the backwards "R," is what UL calls a Component Recognition Mark. It is used only on components that later will be included in a complete product that will subsequently be tested by UL. Such a recognition limits the use to certain conditions only. Plastics are Recognized Components, as certain uses would be safe and some not safe. The UL Component Recognition Mark, RU, limits the use to what is safe. Transformers also could fall into that category. I recently spoke with a manufacturer who tried to tell me that the Component Recognition Mark on his transformer meant the whole product was "UL approved." P.S., it was not! There is another label known as the Field Evaluated Product Mark. If for some reason a product gets into the field that does not have a UL Listing Mark, UL can send an engineer to test a product in the field and that may even include heat testing. For a field testing label, each individual product must be inspected by the UL investigator and so labeled. Not all new products have to be performance tested at UL to get a label. There is a category called "test exempt." When incandescent, fluorescent, and portable lamps are constructed in ways specified by UL, the manufacturer can label the product without having to send it off to the UL labs. Through its long involvement in testing fixtures, UL has determined which fixture geometries and constructions pass the temperature tests. As such, UL has defined a test exempt portion of the incandescent, fluorescent, and portable lamp standards. This portion outlines the critical wattages, dimensions, and spacings needed to pass the temperature test. As such, performance of a temperature test is not necessary by either the manufacturer or UL. When a manufacturer agrees to the test example procedure, they then have to agree to allow the UL Local Field Representative to enter their premises at any time to determine conformance with the standards. Certain fixtures are not accepted within the test exempt category, for example, high-intensity discharge (HID) and wet label. UL PROCEDURES What are the procedures to get a UL Listing Mark for a product? Step one would be for a manufacturer to get the specifications from UL. They are called "Standards" and are available in lighting product cagetories: UL 1570 for fluorescent, UL 1571 for incandescent, and UL 1572 for HID. These Standards are highly detailed and inclusive. If, for instance, you wish to design a fixture to meet wet label requirements, the Standards provide the details explaining the test which simulates rain striking a fixture. The test procedure is very precise and calls for the fixture to be tested under a specific type of sprayhead which can be purchased from UL. The position of the sprayhead, the pressure, and all pertinent details are spelled out exactly. Therefore, a manufacturer may first test a product in their own factory for conformity before contacting UL. When UL receives a fixture, it is first analyzed for physical construction. Parts of the fixture must be of specific dimensions and rigidity. Then performance tests must be conducted, such as for temperature. UL must insure that portions of the fixture do not get dangerously hot. Recessed incandescent fixtures that are designed for installation without contact of insulation must also be tested for the possibility that insulation might accidentally cover it and trap heat, causing a potential fire. A detailed testing procedure is required wherein a box is built of plywood that encloses the fixture so that the walls are 8 1/2 inches from the sides of the fixture. Then insulation is spilled into the box to a height of 4 inches. A sensing device that is part of the fixture must be able to turn the fixture on and off to signal that it is in contact with insulation. According to the National Electrical Code, insulation must not come within 3 inches of a recessed incandescent fixture that is not specifically designed for coverage by insulation. The specifics of the cycling times and temperatures are made very clear in the Standards. Other tests are conducted on the fixture as well, in order to thoroughly confirm safety. For example, floor lamps must go through the tilt test. If the floor lamp is tilted 8 degrees, it should not fall over. If it does fall over, there is the risk that the hot components could start a fire. UL is thorough. For a product to comply with UL Standards, it may also have to carry warning labels in addition to the UL Listing Mark. As an example, there are prescribed labels limiting a fixture's use with specific lamps and wattages. My own opinion here is that lamp limitations are an area where the safety warnings may fail. Warnings often limit lamping to exact lamps, such as the A19, A21, or R40. How can anyone who is not experienced know the meaning of those lamp designations? They refer to lamp shape and size, but that information may not be printed on a lamp or the box they come in! This is not a UL problem as they have no influence on lamp manufacturers in this matter. It is up to lamp manufacturers to voluntarily put the necessary information on the lamp. That matter will not only help in safety, but it will also help those that maintain the lamps. As a lighting consultant, I can tell you that proper maintenance is our greatest lighting hazard. (Perhaps manufacturers will read this and decide to help.) There has been much concern about low-voltage lighting. Presently, UL has the ability to investigate low-voltage fixtures. In the case of a cord-connected portable lamp, if that assembly contains a UL Listed Class 2 transformer, that would not mean that the total lamp would receive the UL Mark for Portable Lamps. For compliance, the total lamp assembly, not just some parts, would have to meet the requirements in UL153. Fixtures that are provided with transformers can be investigated under UL1571. Although there is currently no UL Standard related specifically to low-voltage products, one is being developed. UL always emphasizes that the local authorities, such as city inspectors, have the last word as to what is allowed. UL evaluates for safety, but the local authorities handle the approval for the product and the way it is installed. STANDARD DEVELOPMENT To establish Standards, UL works with industry advisory councils for each product category. Representatives from insurance, inspection authorities, government, industry, and consumers come together to advise UL. Sometimes Standards change, and products that at one time met the Standards have to meet new requirements. In that case, UL reviews all products in its massive files and sends a bulletin to all manufacturers alerting them to the revised requirements as well as their effective dates. UL has international arrangements. For certain products, they can certify products simultaneously for both Canada (CSA) and UL requirements. UL has agreements with many of the world's major testing organizations for testing American products to meet their requirments: VDE in Germany, MITI in Japan, Cenelec in parts of Europe, and more. UL has subsidiary laboratories in Hong Kong and Taiwan, and they offer a service to all manufacturers to advise of the standards in any country. Safety is a concern worldwide. That is a brief look at UL. Now you know the four basic markings: Listed, Classified, Recognized, and Field Evaluated Product. When I, as a member of the lighting profession and the public, think of what could go wrong with the thousands of complex products I use in my home, office, and work, I must emphatically state I am glad we have UL. Vist UL's website, www.ul.com, for more information. January 1992, Architectural Lighting Magazine