I often come across the question of what an acceptable Certified Mark is for UL compliance. Unfortunately, there’s a lot of confusion as to what an NRTL is, what the code requires and such. So here’s some quick clarification:
Specific Information on the 2011 NEC (National Electric Code) requirements:
The National Electrical Code (NEC) – or NFPA 70 – was updated in 2011, as part of its 3-year change cycle. The NEC is published by the National Fire Protection Association (NFPA), and is commonly adopted by U.S. state or local political subdivision, and enforced by the Authority Having Jurisdiction (AHJ).
Many NEC requirements refer to “listed” or “labeled” devices, as defined in Article 100 of the NEC. The NRTL (Nationally Recognized Testing Laboratories) program accredits those organizations that, by whose labeling, the manufacturer indicates compliance with appropriate standards or performance in a specified manner.
What is an NRTL?
A Nationally Recognized Testing Laboratory (NRTL) is an independent laboratory recognized by the Occupational Safety and Health Administration (OSHA) to test products to the specifications of applicable product safety standards – such as those from Underwriters Laboratories (UL) and other standards-writing bodies. An NRTL's function is to provide an independent evaluation, testing, and certification of any electrically operated or gas- and oil-fired product. Intertek is recognized as an NRTL in the United States.
What’s the difference between the UL, CSA, and ETL/other Listed Marks?
All the marks demonstrates the product has met the minimum requirements of widely accepted product safety standards as determined through the independent testing of a Nationally Recognized Testing Laboratory (NRTL). As part of that testing regimen, the product manufacturer has agreed to periodic follow-up inspections to verify continued compliance.
Aren’t manufacturers required to use UL for their compliance testing? Isn’t this mandated by the standards themselves?
The simple answer to both questions is "no." In fact, this misconception has misled many manufacturers, distributors, contractors and end-users to believe that UL must be used as the third-party testing partner. To satisfy the prerequisite of having your products tested by an independent organization, the true legal requirement is that the laboratory that performs the testing be a Nationally Recognized Testing Laboratory (NRTL) recognized by OSHA.
Some Useful Links:
OSHA recognizes four organizations to develop product safety:
Standards from the four are approved for use by ANY of the NRTLs OSHA lists/recognizes to test and certify products.
OSHA’s listing of NRTLs (Nationally Recognized Testing Laboratories)
UL has both a standards development group AND a testing group. The landmark case which MET instigated in the 80s made it so UL no longer had a monopoly and other companies were allowed to be listed as NRTLs.
For further reference, please check the following websites:
OSHA article on NRTLs Approval of Products:
More on NRTL and legal use:
Under the Occupational Safety and Health Administration (OSHA) Act of 1970, OSHA uses Federal regulation Title 29 of the Code of Federal Regulations, Paragraph 1910.303, Subpart S (29CFR 1910.303 (S)), which requires that all conductors and equipment are approved (listed), it also requires electrical equipment to be examined, to ensure it is free of hazards likely to cause harm to employees and be suitable for installation (by listing or labeling).
In addition to OSHA requirements, which cover only the workplace, the USA relies on local building codes to ensure safe residential housing. These codes are based on the requirements of the National Fire Protection Agency, standard NFPA 70, also known as the National Electrical Code (NEC). This code is adopted universally by state and local inspectors who are empowered by their authority having jurisdiction (AHJ).
Some common AHJ (Authorities Having Jurisdiction) personnel known for their strict enforcement of local electrical codes include the City of Los Angeles, the City of Chicago, the State of North Carolina, the State of Oregon, the State of Florida, the City of Orlando and New York City. In these locations' electrical inspectors "red-tag" electrical products that are not listed or labeled. The legal requirement for acceptability to the local AHJ is derived from Article 110 - Requirements for Electrical Installations. As a result, electrical inspectors will look for an NRTL listing, or a field label
The NEC code 800-4 additionally requires all equipment connected to a telecommunication networks to be listed. If equipment is not listed or labeled a supplier may be asked to pay for it to be field labeled on site before it is released for use, and lose a potential repeat order from the customer, due to the delays involved. In addition, AHJ inspectors who are IAEI members exchange information on manufacturers who they know are noncompliant.
Make sure the manufacturer/reseller you’re dealing with knows the code and is 100% compliant. A failure on their part can cost you and your business money, reputation and more.
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