UL certification, NRTL certification, and UL recertification are all mis-used terms. They generally describe one of two different types of approval processes used to demonstrate that a product conforms to the relevant product safety standards.
Here is a breakdown of UL Certification, NRTL Certification, and UL Recertification:
UL Certification
Underwriters Laboratories (UL), now UL Solutions issues many different types of certifications, but UL certified is not one of the types. Generally, when someone refers to an end-use product being UL certified, they mean UL listed, which is a factory-based certification that falls under UL’s Nationally Recognized Test Lab (NRTL) accreditation. UL listings are intended for end-product systems, not components going into end systems.
UL is a private company, and they are the only company that can issue UL listings or other types of UL certifications. Since UL publishes nationally recognized standards, and they certify products to those UL standards, many think that getting UL to do the certification (listing) is mandatory. However, other laboratories can list products to UL standards as well.
For listing type certifications, the main requirement generally is that the laboratory be NRTL-approved. As a result, when the term “UL certification” is used, usually the more appropriate term is NRTL certification. (See below for more information about NRTL certification.)
NRTL Certification
Like UL Certification, NRTL Certification is typically referring to an NRTL listing, which is an ongoing, factory level certification type where the evaluation of a representative test sample is conducted by a Nationally Recognized Test Lab (NRTL) in a laboratory setting.
An NRTL listing requires the following:
- NRTL must be accredited by OSHA to conduct listing certifications (see below)
- Product is to be evaluated at an approved laboratory
- Product will undergo full testing under all foreseeable conditions
- NRTL generates a detailed report of the evaluation and construction
- Quarterly (or sometimes semiannual) factory inspections are conducted
- NRTL certification label must be applied at the factory
Recognition or accreditation of the NRTL comes from the Occupational Safety and Health Association (OSHA). OSHA’s directive is to ensure safe and healthy working conditions for workers. Although OSHA has requirements related to NRTL-certified products in the workplace, many NRTL-approved products and components are intended for residential or personal use.
UL Recertification
UL recertification or relisting typically applies to UL listed equipment that has been modified in the field and now requires re-approval to ensure it continues to meet applicable safety requirements. Although it would stand to reason that a product that has been changed must be recertified, there is no such thing as UL recertification or relisting. Certifications/Listings only apply at the factory level. Once a product leaves the factory, the only similar approval type that can be performed is a field evaluation.
If for instance a UL listed product is modified in the field and an inspecting agency request that it be re-certified, UL could perform a field evaluation on the product, but they cannot relist it. Because field evaluations and listings are handled by different divisions within UL (and most other NRTLs), the team that would perform said field evaluation would not be the same team that did the original listing or any other listings. Much like the term UL certification, UL recertification (or field evaluation) can generally be performed by any accredited Field Evaluation Body (FEB).
One may think that, because this approval type applies mostly to equipment in a workplace, that OSHA would regulate this process. Surprisingly, OSHA has nothing to do with FEBs or field evaluations.
The National Fire Protection Agency (NFPA) is the organization that sets forth the requirements for field evaluations. NFPA 790 and NFPA 791 are the standards by which FEBs are to operate. FEBs can now be accredited to these standards.
Standards
Primary standards used in NRTL certifications and field evaluations are typically identical. These standards are intended to protect against hazards such as electric shock, fire, and moving parts and are tailored towards products being produced in a factory and tested in a laboratory.
These standards work well for NRTL certifications; but what about field evaluations?
Although the intent of both approval processes is the same, the circumstances surrounding the equipment production and stage of life are different. These differing circumstances, some may argue, warrant different requirements for determining compliance.
- The NRTL-specific standards can work well in the field if they (1) are not test-intensive and (2) pertain to products made largely from components that have their own type approvals.
- For product types using few pre-approved components and/or relying heavily on testing, the NRTL standards become difficult to apply in the field.
NFPA was the first to publish standards on how to perform field evaluations—might they also be the first to write standards for products being evaluated in the field? That remains to be seen. In the meantime, FEBs will have to do their best to fill in any gaps.
Is a Field Evaluation or NRTL a Better Fit?
If the product has not yet left the factory, either of these two certification types can be an option. Ultimately, the answer depends on the type of product, the situation, and the intended use. A Field Evaluation is often quicker and more cost-effective, but it has a smaller, more specific scope; an NRTL listing is more time-consuming and expensive, but it may provide a better long-term value if you continue to produce the same products under the same specifications.
Choosing the right compliance strategy saves time and money in the long run. G&M Compliance is an accredited FEB, as well as an expert partner in NRTL listings, which helps the G&M team create the best strategy for your unique situation.
Contact G&M Compliance today to discuss whether field evaluation, UL certification, or NRTL listing is right for your situation.