October 2022

· 6 min read

Electrical FAQs: Do I Need a NRTL? Do Electronics Need To Be UL Certified?

NSF answers frequently asked questions (FAQs) from the electrical industry.
A woman looking up with idea light bulb above head with gray wall in background - Electrical FAQs: NRTL, UL Certification | NSF

When it comes to electrical safety, multiple factors can determine if certification by an Occupational Safety and Health Administration-approved Nationally Recognized Testing Laboratory (NRTL, pronounced “nurtle”) is mandated. The National Electrical Code (NEC), adopted by all 50 U.S. states, specifies in Article 90.7 that all electrical equipment must be approved. Moreover, OSHA states in 29 CFR 1910.310, and the NEC states in Article 110.3, that all equipment in the workplace must be listed and labeled by a NRTL prior to its operation.

Practically speaking, in workplace settings and buildings, electrical products, equipment, machines and appliances are required to be certified by a NRTL.

However, this leaves out many electrical products, such as consumer or home items. Retailers or end users usually demand that products have electrical safety certification, even if OSHA or the electrical code don’t regulate these applications. Certification shows that the product complies with all the necessary safety requirements and was investigated by an independent third party. It also lowers the risk of liability for the manufacturer, so it may be in the manufacturer’s best interest to get certified by a NRTL.

A common follow-up question from electronic equipment manufacturers is, “Do I need UL certification?” Often this question is an inadvertent merging of two different requirements: the “who” and the “what” of certification. Part of the confusion comes from the dual role of Underwriters Laboratories (UL) in the electrical safety industry. UL acts as both a standard writing body and, separately, a NRTL. (Read more about the consensus standard development process.)

The more relevant questions are:

Q: The “who”: Does my product require certification by UL?

A: The final Authority Having Jurisdiction (AHJ) determines acceptance of products and equipment. In most instances, any NRTL with the appropriate scope can provide certification. The OSHA NRTL FAQ page even addresses this:

Does OSHA prefer one NRTL over another NRTL?

Given that each NRTL has met the requirements for recognition, OSHA considers NRTLs recognized for the same product safety test standard to be capable of testing to, and certifying under, that standard.

Some jurisdictions may have specific lists of approved NRTLs, but they usually have multiple options for an acceptable NRTL. The choice comes down to which NRTL suits the manufacturer best based on their priorities (such as turnaround time, price or technical expertise).

Q: The “what”: Is the appropriate certification standard a UL standard?

A: Electrical standards are product-specific, so consulting with an NRTL about your product’s needs is recommended to determine the necessary standard(s) for certification.

Even though many electrical standards for the United States were facilitated or written by UL, these standards are public. Any OSHA-approved NRTL with a given standard in their scope can test and certify products to it. Each approved OSHA NRTL has a published page describing their scope. For example, OSHA’s website shows the scope of NSF’s NRTL.