Product Certification (Listing): Equipment safety standards in the AHJ approval process

By Michael Johnston | Oct 15, 2021

In the construction industry, one of the important objectives, aside from completing the project within set timelines, is attaining code compliance and final approval(s). In the electrical field, there are some key factors that relate to achieving this goal.

Understanding defined terms that appear within the rules is a critical element to properly applying codes and standards. In the National Electrical Code , the word “approved” is simply defined as “acceptable to the authority having jurisdiction.” The AHJ is typically the jurisdiction’s building official who deputizes field inspectors to issue approvals during inspection processes. Other codes and standards may define and use the term “approved” differently.

The NEC outlines the AHJ’s responsibilities in Section 90.4. These include interpreting the Code rules and issuing approvals, as well as granting special permission, which is typically handled by jurisdictions through a variance or modification process, but it is usually formal and in writing.

Section 110.1 indicates that conductors and equipment required or permitted by the NEC are acceptable only if approved. This places the responsibility of the approval process squarely on the shoulders of the AHJ. Inspectors have the authority to approve any installation and use any criteria as the basis for approvals. In exercising the approving authority and responsibility, the AHJ (inspectors) typically rely on additional processes and entities.

Product certification

The NEC and other codes currently use the terms “listed” and “listing,” although the more appropriate and accurate terminology is “product certification.” Product certification includes processes used by qualified electrical testing laboratories to determine if products meet or exceed established product safety standards.

Section 90.7 includes criteria that relates to examining equipment for safety. This includes—but is not limited to—equipment examination, identification, installation and use. Section 90.7 indicates that qualified electrical testing laboratories are often retained to evaluate and list (certify) equipment as meeting or exceeding applicable product safety standards. The evaluation, testing and so forth is typically performed under controlled conditions in properly equipped laboratories.

OSHA maintains a list of nationally recognized testing laboratories as indicated in the informational note to Section 110.3(C). Many jurisdictions use this OSHA list for consistency to remove questions about which testing labs are acceptable.

The NEC does not globally require that all equipment be certified (listed). Specific NEC rules do require certain wiring methods and materials to be certified (listed), but such a requirement usually appears within the specific rule applicable to the equipment and installation.

The term “listed” has been in codes for years, and it is generally related to a “list” of manufacturers that have achieved recognition by a qualified electrical testing laboratory as capable of manufacturing products that meet applicable safety standards.

The recognized manufacturers of the certified products must provide the product with a certification mark—label, engraving, molding or other mark—which assures compliance with applicable safety standards beyond the NEC .

The AHJ generally relies on the certification (listing) mark as a basis for approval by the AHJ, but not always. Remember, the AHJ often uses much more criteria to determine compliance and ultimately issue approvals. The NEC requirements and the suitability of certified (listed) products must be verified and carefully considered by the (AHJ) inspector in the field when fulfilling their approving duties.

One of the most important factors about installation and approval of certified (listed) equipment is use. Yes, how a product is installed and used is key to determining eligibility for approval by the AHJ. Section 110.3(B) has clear language indicating that listed or labeled equipment be installed in accordance with any instructions. Some instructions are provided on equipment labels, and often separate instructions are included with the equipment. Following installation instructions is significant when trying to achieve approval(s). While a product may bear a certification (listing) mark, its suitability for a particular application may be in question. Field inspections are important to verify code-compliance of all equipment and installations cannot be underestimated.

The electrical safety system relies heavily on three key components: installation codes, product safety standards and inspection for compliance. A fourth and equally important component is qualified electrical contractors and workers.

About The Author

A man, Mike Johnston, in front of a gray background.

Michael Johnston

NECA Executive Director of Codes and Standards

JOHNSTON is NECA’s executive director of codes and standards. He is a member of the NEC Correlating Committee, NFPA Standards Council, IBEW, UL Electrical Council and NFPA’s Electrical Section. Reach him at [email protected].






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