Underwriters Laboratories
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Underwriters Laboratories (Inc.) is a well-known laboratory with headquarters in Northbrook, Illinois that develops standards and test procedures for materials, components, assemblies, tools, equipment and procedures, chiefly dealing with product safety and utility.
UL does not "approve" any product. Rather it tests product samples and permits acceptable products to carry the UL certification mark, as long as they remain in conformity with the standards and with the samples tested to those standards. Placing the mark on untested products would be a type of trademark infringement and violate the UL license to the manufacturer. UL maintains a list of over 100,000 products it has tested and that database is available online to the public.
A product with Underwriters Laboratories listing is said to be "UL Listed." Purchasers can identify such products by the distinctive UL Mark [1]. The company's "file number" may be on the label (typically a letter followed by 5 or 6 numbers (ie E12345)). The "UL File number" can be used to look up a certificate at the UL web page.A manufacturer of a Listed product must demonstrate compliance of its design with the appropriate UL standards, and then demonstrate that it has a program to ensure that each copy of the product will similarly meet the essential criteria. In some cases a component may be "UL recognized", meaning UL has found it acceptable for use in a product that will be tested for UL Listing.
If a product design is modified, a representative example may need to be re-tested before the UL mark can be attached to the new product or packaging. UL also ensures the product is manufactured as tested, with unannounced Follow-Up Inspections at the manufacturing locations, usually conducted several times per year.
UL has ratings standards for hundreds of types of components and products, even bullet-proof vests. The average person may be more familiar with UL-rated products such as home electrical appliances. A typical standard for electronic products includes not only requirements for electrical safety, but also fire spread and mechanical hazards (such as sharp or moving parts or tipping over). Just because a product has a UL listing does not mean the product will perform acceptably or that it is safe under all conditions.
A UL mark is a representation but not a guarantee that a marked product conforms to the corresponding UL standard. UL is a private company; in and of itself, the mark does not carry any legal weight beyond that of any other trademark. In this sense it is different from the CE mark, or from the FCC Part 15 requirements on electronic devices, which are explicitly required by law. In practice, however, it may be extremely difficult to sell certain types of products without UL listing; large distributors may be unwilling to buy a product without it, or the use of unlisted equipment may invalidate insurance coverage. It is common practice in many fields to specify UL-marked equipment or to specify materials in terms of their UL ratings, even when there is no explicit requirement to do so.
In the past twenty years great strides have been made in harmonizing international safety standards, and now the UL mark has attained reciprocity with some other national testing laboratories (i.e., the standards are similar and the tests are similar). The label for products certified for both Canadian and U.S.A. includes "C" and "US Listed" below the UL logo.
A moderately famous video clip shows UL researchers demonstrating the risks of certain models of deep-fat turkey fryer. This serves as a suggestion of the importance of this sort of product testing. [2] UL refused to certify any turkey fryers whatsoever with its mark; but since the mark is not legally required, it was (and is) still possible to buy them at major retailers.
The European analog of the UL mark is the CE mark. The CE mark deals with a larger set of issues than the UL mark, though. For example, UL does not deal significantly with questions of electromagnetic compatibility, but the CE mark standards include the equivalent of the FCC Part 15 regulations.
[edit] History
Underwriters Laboratories was created during the World Fair when Thomas Edison demonstrated electric light bulbs. Effectively, concerns were put towards Edison on the safety of his devices, someone from the crowd charged for his service of assuring the safety of everyone by inspecting Edisons devices, thus UL was born.
[edit] See also
- Product certification
- Bounding
- Fire test
- ETL SEMKO - A competing testing laboratory in the USA, part of Intertek, based in London.
- Canadian Standards Association - Provides similar services in Canada and serves as a competitive alternative for USA products
- CE mark - A standards conformance mark used in Europe
- Consumer Reports
- Good Housekeeping Seal
- Quality control
- Safety engineering
- UL94 - flamability standard
