ETL vs UL: What Is the Difference?

ETL vs UL compares two safety certification marks for electrical products sold in North America. A UL Listed mark means a product was tested by UL Solutions, the testing business of Underwriters Laboratories, founded in Chicago in 1894. An ETL Listed mark means it was tested by Intertek, whose ETL name goes back to Thomas Edison’s Lamp Testing Bureau of 1896. Intertek is headquartered in London.

Both companies are Nationally Recognized Testing Laboratories (NRTLs). The US Occupational Safety and Health Administration (OSHA) runs the NRTL programme under 29 CFR 1910.7 and requires most electrical equipment used in US workplaces to be listed or approved by one. CSA Group, TÜV SÜD, TÜV Rheinland and SGS are also NRTLs, so UL and ETL are the best known marks rather than the only ones.

The practical difference is small. UL writes many of the North American safety standards, and Intertek tests to those same standards. A listing from either lab shows that a sample passed the standard and that the factory is inspected to keep it that way.

For compliance, yes. OSHA treats every NRTL equally within its recognised scope, and US electrical inspectors working to the National Electrical Code (NFPA 70) accept equipment listed by any NRTL. Both labs also run follow-up programmes: inspectors visit the factory several times a year, unannounced, to check that production still matches the tested sample and that critical components have not been swapped.

Where the two differ is in the commercial detail. UL is the older and more widely recognised name, and some specifications, insurers and buyers still write “UL listed” when they mean “NRTL listed”. Intertek is often chosen for faster test slots or because a manufacturer already uses it for other markets. If a tender insists on UL, ask whether an equivalent NRTL listing is acceptable; it usually is, but the buyer has to agree.

A UL or ETL logo on its own does not tell you what was tested. The wording around the mark does, and it matters when a product goes into a control panel or another manufacturer’s equipment.

For computers and other IT equipment, the standard behind either mark is now UL 62368-1, the hazard-based standard that replaced UL 60950-1 in the USA at the end of 2020. Industrial control panels are built to UL 508A, laboratory and test equipment to UL 61010-1, and medical electrical equipment to UL/IEC 60601-1. Always check the listing in the lab’s own database: the model number on the certificate has to match the product you are buying.

Many of the fanless industrial computers we supply list UL 62368-1 among their approvals, and a number of our unmanaged industrial switches list UL 508 for use in control cabinets. Our guide to UL computers for industrial control panel builders explains what a panel shop needs from the hardware inside a UL 508A panel.

Neither mark is required in Great Britain, because NRTL listing is a US and Canadian system. Electrical products sold in Britain need UKCA or CE marking instead, and for most electronics that is a manufacturer’s self-declaration against harmonised standards such as BS EN IEC 62368-1 for safety and the EMC Regulations 2016 for interference. The UK government has extended recognition of CE marking indefinitely for most of the product rules that cover electronics. For medical equipment the safety standard is IEC 60601-1, with extra regulatory steps on top.

The link between the systems is the IECEE CB Scheme. A CB test report to IEC 62368-1 from an accredited lab can support a UKCA or CE declaration and speed up an NRTL listing, so equipment sold on both sides of the Atlantic is often tested once and certified twice.

Remember that UL and ETL cover safety only. Radio-frequency emissions are a separate requirement: FCC Part 15 in the USA, ISED in Canada, and the EMC rules behind UKCA and CE in Britain and Europe.

We supply industrial computers, switches and power supplies with their safety approvals listed on each product page, and check that the listings in a build match your market, panel or site requirements before the system ships.