For decades, confusion has surrounded the relationship between OSHA’s Nationally Recognized Testing Laboratory program and the field evaluation of unlisted electrical equipment.

Some authorities having jurisdiction, equipment owners, and contractors have assumed that an organization recognized by OSHA as an NRTL must also have been evaluated and approved by OSHA to perform field evaluations.

That assumption is incorrect.

OSHA’s NRTL recognition program addresses product testing and certification within an NRTL’s formally recognized scope. It does not evaluate or accredit an organization’s field evaluation program. NRTL recognition alone has never established that an organization possesses the personnel qualifications, impartiality controls, procedures, technical competence, or management system required to evaluate unlisted equipment at an installation site.

This distinction is not a new interpretation promoted by independent Field Evaluation Bodies. UL itself explained the distinction clearly in one of their 2011 publications on this very topic.

What OSHA Actually Recognizes NRTLs to Do

OSHA describes an NRTL as a private-sector organization recognized under 29 CFR 1910.7 to perform testing and certification of products using consensus-based test standards.

Each NRTL receives a defined scope of recognition. That scope identifies the test standards and products for which OSHA has determined that the organization can perform independent safety testing and certification. A product properly certified under an NRTL program may bear the organization’s registered certification mark.

That is the central purpose of OSHA NRTL product certification: determining that products covered by the NRTL’s recognized scope comply with applicable product safety test standards.

Traditional product certification commonly includes:

• Testing representative products against recognized standards
• Issuing a certification or listing
• Authorizing use of a registered certification mark
• Maintaining a certification agreement with the manufacturer
• Conducting follow-up inspections at manufacturing facilities
• Confirming that subsequently manufactured products remain consistent with the certified design

OSHA’s recognition of an NRTL is meaningful and important. However, it must not be expanded beyond what OSHA actually assesses.

OSHA recognition does not automatically qualify every service offered by an NRTL. A company can operate an OSHA-recognized certification program while also offering engineering, consulting, inspection, or field evaluation services. Those additional services do not become OSHA-accredited merely because the same company is an NRTL.

An Industry Leader Highlights OSHA’s Shortcomings For Unlisted Equipment Accreditation

In late October of 2011, UL published its fourth issue of Electrical Connections, which had an article titled “Field Evaluations: New Standards NFPA 790 and 791,” that announced and reviewed the new (at that time) NFPA 790 and 791 standards. These newly-published standards came from the National Fire Protection Association (NFPA) and were explicitly designed to set the qualifications, guidelines, and processes/procedures for field evaluation bodies (FEBs) and their approach for evaluating unlisted equipment in the field.

In this article, UL explained that OSHA had an accreditation program for NRTLs but no corresponding program for organizations evaluating products in the field.

UL stated this very plainly:

“OSHA does not assess an organization’s abilities or credentials to field evaluate products.”

That sentence draws the line clearly.

UL further acknowledged that some testing organizations claimed to be recognized for field evaluations by virtue of their NRTL status. UL rejected that reasoning. The article explained that, at the time, some jurisdictions developed their own qualification procedures, while others limited field evaluations to NRTLs even though OSHA had not assessed those NRTLs specifically for field evaluation competence.

This was not a criticism of NRTLs. It was recognition of a gap. OSHA NRTL product certification and the evaluation of one-of-a-kind, modified, used, imported, or otherwise unlisted equipment are different conformity-assessment activities requiring different controls.

Why Traditional Certification Does Not Solve Every Equipment Problem

The American electrical safety system relies heavily on products being listed and labeled before they leave the factory. That system works well for standardized products manufactured repeatedly under controlled conditions.

However, not every piece of equipment follows that path.

Industrial facilities routinely receive equipment that is:

• Custom built for a single installation
• Produced in very limited quantities
• Imported without a certification acceptable in the United States
• Modified after its original listing
• Assembled from listed components without being listed as a complete machine
• Relocated or repurposed in a way that affects its original certification
• Used research, production, or process equipment
• Constructed specifically for semiconductor, laboratory, automation, or manufacturing applications

These machines may not be candidates for a conventional factory certification program. Nevertheless, the owner, employer, electrical inspector, or other AHJ still needs competent evidence that the equipment can be installed and operated safely.

The NEC gives AHJs responsibility for approving equipment and provides factors for evaluating equipment under Section 110.3(A). OSHA workplace rules also require electrical equipment to be acceptable or approved as applicable. Neither fact means OSHA has accredited a particular organization to perform a field evaluation.

Before nationally recognized field evaluation standards existed, AHJs had few consistent tools for determining which organizations were qualified to provide this evidence.

NFPA 790 and NFPA 791 Filled the Compliance Gap

The electrical safety community recognized that field evaluations needed their own nationally consistent structure. That work ultimately produced NFPA 790 and NFPA 791.

NFPA 790 establishes competency requirements for third-party Field Evaluation Bodies. Its framework addresses organizational and technical subjects such as:

• Personnel qualifications and demonstrated competence
• Training and experience
• Product-category-specific authorization
• Impartiality and conflicts of interest
• Documented field evaluation procedures
• Record-keeping and report controls
• Test and measurement equipment
• Technical review and conformity decisions
• Management responsibility and quality controls
• Proper control of field evaluation labels and Statements of Conformity

NFPA 791 addresses the procedures for evaluating unlabeled electrical equipment. It provides a consistent technical process covering subjects such as construction review, markings, grounding and bonding, overcurrent protection, disconnecting means, environmental suitability, electrical testing, documentation, corrective actions, and communication with the AHJ.

Together, these documents supplied what OSHA NRTL product certification did not: a national framework focused specifically on the organizations and procedures used for field evaluation.

NFPA did not transform field evaluation into product listing. Instead, it established a structured method for evaluating particular equipment at or in connection with a specific installation. The final acceptance of that equipment remains with the AHJ.

NRTL and FEB Are Separate Qualifications

An NRTL can also operate as a Field Evaluation Body. Many do. However, the organization’s NRTL recognition and its FEB qualification must be treated as separate credentials.

An NRTL does not become an accredited FEB merely because it is an NRTL. It must demonstrate compliance with the applicable field evaluation requirements through an appropriate FEB accreditation or jurisdictional approval process.

The reverse is also true. An accredited FEB does not become an NRTL by earning FEB accreditation. The FEB is qualified for the field evaluation activities described in its accredited scope, not for the operation of an OSHA-recognized product certification program.

The distinction can be summarized simply:

Neither credential should be represented as something it is not.

Independent Accreditation Made FEB Competence Verifiable

Once NFPA 790 and NFPA 791 established recognized criteria, accreditation bodies were able to create programs that independently assessed Field Evaluation Bodies against those requirements.

Organizations offering FEB accreditation programs have included:

• International Accreditation Service, or IAS
• American Association for Laboratory Accreditation, or A2LA
• American Quality and Accreditation Institute, or AQAI
• ANSI National Accreditation Board, or ANAB

These programs can evaluate an FEB’s management system, personnel competence, impartiality, field procedures, reporting, testing practices, and authorized product categories. Depending on the program, accreditation may also incorporate ISO/IEC 17020 or ISO/IEC 17025 requirements.

IAS, for example, states that its FEB program assesses compliance with NFPA 790 and NFPA 791 and gives AHJs evidence they can use when approving Field Evaluation Bodies. IAS Field Evaluation Body Accreditation

A2LA offers FEB accreditation options based on NFPA 790 and NFPA 791, including an option combined with ISO/IEC 17020. A2LA Field Evaluation Body Accreditation

ANAB similarly maintains a field evaluation accreditation program incorporating NFPA 790 and NFPA 791. ANAB Inspection Body and FEB Accreditation

This accreditation path is open to qualified organizations regardless of whether they also operate an NRTL certification program. An NRTL may apply and demonstrate FEB competence through the same kind of independent assessment available to organizations such as Lewis Bass.

Lewis Bass Is Accredited for Field Evaluation

Lewis Bass International Engineering Services is accredited by IAS as Field Evaluation Body FEB-122. The accreditation demonstrates that Lewis Bass has met applicable requirements of IAS AC354, NFPA 790, NFPA 791, and ISO/IEC 17020 for the services identified in its accredited scope.

Lewis Bass did not become an NRTL, nor does it claim that OSHA granted its FEB accreditation. Its qualification comes through an accreditation program specifically designed to assess Field Evaluation Bodies.

That is precisely the distinction the industry needed.

A customer or AHJ comparing Lewis Bass with an NRTL should not ask only, “Is this organization an NRTL?” The more relevant question for unlisted equipment is:

What independent evidence establishes this organization’s competence to perform field evaluations for this equipment category?

For an accredited FEB, the answer should be found in its FEB certificate and detailed scope of accreditation.

The Line in the Sand

The historical and regulatory record supports several clear conclusions:

1. OSHA recognizes NRTLs for testing and certifying products within defined scopes.
2. OSHA’s NRTL program does not separately assess or accredit field evaluation competence.
3. NRTL status alone is not FEB accreditation.
4. UL publicly acknowledged this distinction in 2011, stating that OSHA did not assess an organization’s field evaluation abilities or credentials.
5. NFPA 790 and NFPA 791 created a dedicated competency and procedural framework for field evaluations of unlisted equipment.
6. Accreditation bodies subsequently developed programs through which NRTLs and non-NRTL organizations alike can demonstrate FEB competence.
7. The AHJ retains final authority over acceptance of the FEB and the evaluated equipment.

OSHA NRTL product certification remains a vital part of the American product safety system. But it is not, and has never been, a substitute for a program specifically assessing the competence of organizations that evaluate unlisted equipment in the field.

Recognizing this distinction does not diminish NRTLs. It protects the integrity of both systems. Product certification should be represented as product certification, and field evaluation accreditation should be represented as field evaluation accreditation.

For unlisted equipment already installed or destined for a particular location, the relevant credential is demonstrated competence as a Field Evaluation Body, supported by an appropriate scope of accreditation and accepted by the AHJ.

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