Facebook  |  Twitter  |  Google Plus  |  LinkedIn  |  Print

IECEx Scheme

The IECEx Scheme (International Trade of Electrical Equipment used in Explosive Atmospheres) is an outgrowth of the CB Scheme, or the Scheme of the IECEE – the International Electrotechnical Commission System for Mutual Recognition of Results of Testing of Electrical Equipment – and offers U.S. manufacturers an opportunity to increase global marketability.

The IECEx Scheme facilitates the international exchange and acceptance of product-safety test results among participating laboratories for national approval or certification in one or more countries, normally without the need for additional testing. This is a universal goal among suppliers, consumers, and interested parties stated as “one standard, one test, accepted everywhere.”

The objective of the IECEx Scheme is to facilitate international trade in electrical equipment intended for use in explosive atmospheres (referred to as Ex equipment).

The Ex scheme applies to manufacturers of:

  • Electrical apparatus for explosive gas atmospheres
  • Electrical apparatus for the detection and measurement of flammable gases
  • Electrical products such as switches, outlets and outlet boxes, circuit breakers, electric motors, and lighting used in hazardous environments

According to the IEC, these manufacturers can expect:

  • Reduced testing and certification costs
  • Reduced time to market
  • International confidence in the product assessment process
  • One international database listing

There are currently 17 Accepted Certification Bodies (ACBs) in 22 countries participating in the IECEx Scheme as follows:



South Africa


Republic Korea







United Kingdom


New Zealand

United States of America








The recognition of each member organization identifies the Standards and protection methods with which the organization participates (see IECEx Bulletin on the IECEx website).


Historically, obtaining all of the necessary national safety certifications for electrical products used in explosive atmospheres has been a difficult, time-consuming and expensive proposition. To facilitate the entry of U.S. manufacturers into the international market, the United States applied to join the IECEx Scheme on February 9, 2001 and was accepted in April of 2001.

In the Ex Scheme, the IECEx accredits Accepted Certification Bodies (ACBs) to test and certify conformity of electrical equipment used in explosive atmospheres with internationally harmonized product safety standards and issue “Ex” test certificates and test reports. By significantly reducing duplicate testing, the Ex scheme provides substantial advantages over the previously available methods of obtaining multiple international certifications.

Operating Concepts

The IECEx Scheme is a multilateral agreement among participating countries and certification organizations based on the use of international (IEC) Standards. If a member’s national standards are not yet completely harmonized with the IEC standards, a transitional period is allowed.

The transitional period can vary for different standards and is intended to allow time for harmonization between the IEC standards and the country’s national standards and to obtain national acceptance of IECEx Certificates of Conformity and the IECEx Mark of Conformity.

The IECEx Scheme utilizes Ex test certificates to attest that product samples have successfully complied with the appropriate tests and are in compliance with the requirements of the relevant IEC Standard.

How to Participate

All countries, regardless of membership status with the IEC, may join the IECEx. The National Committee of each member country must then designate its Accepted Certification Body or Bodies (ACBs) that will be responsible for recognizing and issuing IECEx test reports and certificates.

In the U.S., the National Committee is known as the USNC/IECEx. NEMA provides the Secretary for that organization. The USNC/IECEx coordinates the application of U.S. ACBs to the IECEx Management Committee.

Each ACB must separately apply for recognition of specific IEC Standards it intends to use within the Scheme. The issuance and acceptance of test reports by ACB’s within the IECEx Scheme are limited only to those IEC Standards for which the ACBs are officially recognized. A periodically updated list of all ACBs and the scopes of their recognition appear on the IECEx website.

U.S. National Committee For The IECEx (USNC/IECEx)

The IECEx Scheme Working Group, a task force established by the chairman of the U.S. National Committee of the IECEE (USNC/IECEE), was formed for the purpose of exploring the feasibility of U.S. entry into the IEC’s Explosive Atmosphere Scheme. In addition, the working group was tasked with identifying the principal harmonization and policy issues that would have to be addressed, and for preparing the U.S. application for entry into the Scheme.

The preparation phase continued through most of 2000. In December 2000, the USNC/IEC Council granted approval for the creation of the U.S. National Committee of the IECEx and for this body to file an application for formal entry into the IECEx Scheme. The IECEx Scheme Working Group transformed into the USNC/IECEx during the meeting held at the NEMA Headquarters on January 17, 2001.

The principal purposes of the USNC/IECEx are to:

  • Serve as the U.S. Member Body of the IECEx System for conformity testing and certification of electrical equipment used in explosive atmospheres.
  • Coordinate with U.S. Accepted Certification Bodies (ACBs) to assure that National Standards are harmonized with IEC standards used in the IECEx Scheme
  • Process applications for submission to the Secretariat of the IECEx Scheme
  • Develop national viewpoints and comments in all matters pertaining to the IECEx


Kerry Mcmanama, Underwriters Laboratories Inc., is the current chairman of the USNC/IECEx. Vice chairman is Steven Blais, Emerson/EGS Electrical Group, and William Fiske, Intertek Testing Services, is the treasurer.

The operating procedures of the USNC/IECEx were published on September 10, 2001, and were revised on July 11, 2002.


Membership in the USNC/IECEx is open to all U.S. national persons (organizations, companies, government agencies, or individuals) who are directly and materially affected by the committee’s activity. The IEC states “participation shall be fair and equitable without dominance by any single interest.”

Anyone interested in becoming a member shall make a request in writing to the USNC/IECEx Secretary stating why they believe their organization is directly and materially affected by the committee’s activities.

Accepted Certification Bodies (ACBs)

An Accepted Certification Body (ACB) is a certification organization that grants nationally recognized conformity assessment certificates to electrical products used in explosive atmospheres. To be accepted as a member of the Ex Scheme, an ACB must meet specified requirements with regard to its internal quality system and technical competence. Competence is judged by reference to ISO/IEC 17025, Guide 65 and IECEx Technical Guidance Documents.

For additional information concerning the IECEx scheme and its operation at the international level, visit the IECEx website.

For further information on the IECEx Scheme and how to make application to be recognized as an ACB, contact:

Joel Solis
Secretary, USNC IECEx
1300 North 17th Street, Suite 1847
Rosslyn, VA, 22209
Phone: (703) 841-3267
Fax: (703) 841-3367
E-Mail: joel_solis@nema.org


Copyright © NEMA. All rights reserved. (703) 841-3200, 1300 North 17th Street, Suite 900, Arlington, Virginia 22209