Key Conformance Marks In Electronic Design

Jan. 29, 2009
UL and Other Safety Markings

All products have to meet various regulatory compliance requirements for safety, emissions, and other criteria before they can be sold globally. All industrial nations require specific marks on products before they can be sold there. Testing and certifying compliance are the keys to getting those marks. For electronic products, safety and electromagnetic compatibility (EMC) and electromagnetic interference (EMI) are key certification issues.

In the U.S., the Federal Communications Commission (FCC) dictates the testing requirements for EMC and EMI. Products can be Class A, marketed for commercial or industrial use and not intended for home use, or Class B, targeting home use. Class B requirements tend to be more strict than Class A requirements.

Stateside, the registered certification marks of Underwriters Laboratories (UL) mean that UL or a nationally recognized testing laboratory (NRTL) has tested and evaluated representative samples of the product and determined that it meets UL’s specified product safety requirements (a). The negative impact of lacking a UL mark may be more de facto than de jure, but it’s just about as crippling.

The Occupational Safety and Health Administration won’t let products without the mark be used in businesses. Also, under the National Fire Code, electrical inspectors won’t allow the product to be installed in buildings. You may be obligated contractually to have a UL mark on your product, or some customers might not sell it. And, savvy consumers look for the UL mark on products they buy.

In Europe, it’s cut and dry. All products must have a CE or “Conformite Europeenne” mark (b). The CE mark is all-inclusive. It shows that the product complies with the “essential requirements” of European laws or directives. It also indicates the product’s conformance to legal requirements with respect to safety, health, the environment, and consumer protection in the European Union.

The marking is mandatory for certain product groups, but it can be achieved either by using an external test house like an NRTL in the U.S. or by a company’s internal self-certification process. This includes companies in the U.S. A great deal of information on the subject is available from the U.S. Department of Commerce at

For Canada, standards are determined and required by law by the Standards Council of Canada (SCC). In general, products require the cUL, a mark from UL, expressly for Canada (c). Products also require the Canadian Standards Association (CSA) mark. U.S. FCC approval is generally accepted for emissions.

UL issues the Recognized Component mark (d) or its Canadian variant to transformers, relays, and other subcomponents of power supplies. Using recognized components in your power supply doesn’t guarantee conformance. That’s where clearance and creepage and all of the other good practices, along with EMC/EMI performance, come in. But it does provide a foundation.

Japan uses the Voluntary Control Council for Interference by Information Technology Equipment (VCCI) mark, which certifies EMI compliance (e). It also employs the Denan/PSE mark, which targets electrical safety (f). “Denan” comes from “denki youhin anzen hou,” as denki means “electrical,” and anzen means “safety.”

Korea’s Ministry of Information and Communication offers the MIC mark (g). Most MIC standards are based on IEC standards. Taiwan’s Bureau of Standards, Metrology and Inspection offers the BSMI mark (h). The China Compulsory Certificate (CCC) integrates the former “CCIB” Safety Mark and the “CCEE” (also known as the “Great Wall” Mark) for electrical commodities (i). Several agencies on the Web offer help in obtaining the CCC.

See associated figure

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