This list represents a sampling of electrical product testing and certification laboratories and is neither an endorsement nor a list of recommended service providers. The user should research the companies to find a laboratory or product certifier best suited for his or her needs. For more information about conformity assessment, visit the NEMA ABCs of Conformity Assessment page.

The list is broken down into three categories as follows:

In some cases, a laboratory may be recognized by more than one of the three schemes under their individual rules of operation.

The user is encouraged to visit the websites of the individual schemes for specific contact information as well as detailed listing of the capabilities for which the laboratories are recognized.

In addition to these product certifiers, there are many other testing laboratories in the United States, some of which conduct testing of electrical products but which may not operate a certification program involving an issuance of a certification mark. The National Institute of Standards and Technology (NIST) publishes a Special Publication SP 903 with information on over one hundred testing laboratories, some of which test electrical products and components. There are indexes, which can be used to locate those that engage in the testing of electrical products.

In addition, the American Society for Testing and Materials (ASTM) publishes LAB01, Directory of Testing Laboratories. The 2001 Edition contains over 1000 testing laboratories, some of which test electrical products and components.

IECEE CB Scheme

The IECEE CB Scheme is a worldwide program in which product certifiers are recognized for their ability to test and certify electrical products in various product categories related to the electroindustry. In the U.S. there are currently six recognized National Certification Bodies (NCBs) as follows:

IECEx Scheme

The IECEx Scheme is a worldwide program in which product certifiers are recognized for their ability to test and certify electrical products and enclosures used in hazardous locations where the presence of gas or dust can result in an explosive condition in the presence of electrical discharges that are not contained. At the present time, there are three Accepted Certification Bodies (ExCBs) recognized as follows:

OSHA NRTL Program

The U.S. Department of Labor's Occupational Safety and Health Administration (OSHA) operates a program to qualify Nationally Recognized Testing Laboratories (NRTLs) for their ability to certify products for safe use in the workplace. At the present time there are seventeen NRTLs, see Current List of NRTLs.