ETL listing means that Intertek has determined a product meets ETL Mark safety requirements.. UL listing means that Underwriters Laboratories has determined a product meets UL Mark safety requirements. Silk-screened on products as logos, the marks prove that products have passed public safety testing.
Intertek and Underwriters Laboratories each qualify as nationally recognized testing laboratories. The nationally recognized testing laboratory program is part of a U.S. Occupational Safety and Health Administration directive to make sure products are safe for use by workers.
However, many products designed for use outside the workplace also receive product testing and certification. Such products include household appliances, lighting, automotive products, industrial machinery and medical devices. Approved products are emblazoned with certification marks.
Intertek and Underwriters Laboratories each test samples of a product with respect to specific product properties to ensure that it meets industry standards. Underwriters Laboratories has developed more than 800 standards, such as UL 1492: Audio-Video Products and Accessories and UL 1411: Transformer and Motor Transformers for Use in Audio-, Radio- and Television-Type Appliances. Intertek tests for national and international standards produced by groups such as the American National Standards Institute, the American Society of Mechanical Engineers and National Science Foundation.
Intertek and Underwriters Laboratories also test and approve products for use in Canada. However, the Canadian Standards Association does likewise, issuing its own CSA Mark. Within the European Union, Conformance European performs similar services with its CE Mark.