Definition:
A Nationally Recognized Testing Laboratory (NRTL) is a U.S.-based organization recognized to perform certification of products to applicable safety standards. The owner of the list of the NRTL is OSHA.
This is often a confusing topic in the US, as people confuse the company, United Laboratories (UL), as being the only entity that can certify products. The reality is that ANY entity on the NRTL (which includes UL) can certify products. See here for a complete list of labs by OSHA.
What is confusing is that UL has a LOT of the business of certifying/listing products in the U.S. AND they are in the business of writing standards. So another major company on the NRTL like Intertek, is likely to do testing to a UL standard. But they are going to “mark” the product with the Intertek stamp of ETL. Not a UL stamp. An untrained person could challenge that this item is not listed because there is no UL logo on it.
Key Points:
- Focuses on electrical product certification.
- Different from Notified Bodies operating under EU law and AHJs in the US.
- Related to but distinct from the Certified Body.
Example:
Intertek and UL are both members of the NRTL that certifies industrial control panels to UL 508A. When the National Electrical Code (NEC) says a component, “shall be listed,” what it means is the equipment needs to approved by a lab on the NRTL against a recognized standard.
See also: Certification Body, Notification Body (NoBo)
Cited Source:
- OSHA NRTL Program Guidelines.
- See complete list of NRTLs here