What's the difference between ETL and UL listed electrical outlets? Which should I purchase?

Question

I want to be legal and pass home inspection. I'm in California in the USA, replacing some electrical outlets.

ETL appears to be less-common, but equally recognized:

The main difference between UL and ETL listed products is that ETL doesn’t create its own standards for certification. UL develops standards that are used by other organizations, including ETL.

Both are Nationally Recognized Testing Laboratories(NRTLs). They serve as non-governmental labs that operate independently. Additionally, they are recognized by OSHA as being suitable labs to test products based on safety standards.

Will ETL GFCI outlets pass a home inspection for a garage that's apparently required to have GFCI outlets?

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This is one of the GFCI "ETL Certified" outlets on Amazon I am considering. $20 for 2.

Other references:

1. Google search for "etl vs ul"

Answer 1

It appears California leaves recognition of testing labs all the way down to city level, an example of this is the City of Los Angeles, but there should be no issue with ETL for GFCI receptacles.

The National Fire Protection Association (also a private company and owner of the NEC) doesn't specify OSHA NRTL's or name UL or any other testing labs in NFPA70 (the NEC). It says:

110.3(C) Listing. Product testing, evaluation, and listing (product certification) shall be performed by recognized qualified electrical testing laboratories and shall be in accordance with applicable product standards recognized as achieving equivalent and effective safety for equipment installed to comply with this Code.

Informational Note: The Occupational Safety and Health Administration (OSHA) recognizes qualified electrical testing laboratories that perform evaluations, testing, and certification of certain products to ensure that they meet the requirements of both the construction and general industry OSHA electrical standards. If the listing (product certification) is done under a qualified electrical testing laboratory program, this listing mark signifies that the tested and certified product complies with the requirements of one or more appropriate product safety test standards.

Many Authorities Having Jurisdiction defer recognition by ordinance to labs recognized by OSHA as NRTL's. Not all NRTL's do electrical testing, and not all approvals apply to all countries. For example a UL symbol with the letters AR below it are only approved for use in Argentina, and NSF doesn't test electrical.

Answer 2

TLDR; As a consumer, they are effectively the same and say that a product is safe to use. Any listed product may be otherwise junk, but it at least fails safely or satisfies the conditions of a standard. Also, if your inspector is looking at the back of your electrical outlets, I truly pity what other abnormal scrutiny your inspector has devised as torture.

There are two relevant things to discuss here:

1. Standards that products can be certified against (e.g. UL standards, IEC standards, ISO standards, etc)
2. Nationally Recognized Test Labs (e.g. UL, ETL, CSA, TUV, etc) that can certify a product meets a particular standard and create a listing that a manufacturer puts on their product so a consumer can go look up the listing

Standards fall into two categories:

1. Standards that are required to be met in order legally sold in the US for a particular product category.
2. Standards that are optional to implement

Usually, unless there is a strong reason to certify that a product meets an optional standard, companies will probably only pay for testing to standards that are required or optional but industry standard across manufacturers so as to not lose competitive advantage when a store is deciding which products in a category it should put on its shelves. Theoretically, a manufacturer could try to certify their GFCI outlet is a toaster (and if they succeed, maybe the standard should be rewritten...) but then they have earned a listing from that test lab that certifies the product meets that standard. By putting that listing on the product, they are making it so you can look up that listing number and find out what standards it was successfully tested to comply with. In practice, the typical consumer does not do this for something like a GFCi outlet since the big box stores have already done the background checks to make sure the products they put on sale are tested for the correct categories.

To certify that a product meets those standards, a Nationally Recognized Test Lab (NRTL) is paid to test the product and certify against particular standards and then make a listing available that a company puts on its product so that consumers of the product can go look up what that listing means. The listing should almost always be for testing against the correct standards for a product category if you buy it off the shelves of a major store in the US. That said, counterfeit items from some suppliers are becoming a problem (e.g. some third party suppliers on sites like Amazon). Counterfeiters will happily mold in or slap a label on their product with a legitimate listing from NRTL when it hasn’t earned that mark (just like counterfeiting the name of a manufacturer really—doing everything to impersonate someone else’s product with as many marks of authenticity as possible).

ETL is just the mark of one of many Nationally Recognized Test Labs who certify products to published standards. UL, CSA, and TUV are a couple others to name a few. In addition to being a test lab, UL publishes its own set of recognized standards that other NRTLs may also certify that a product meets.

Answer 3

There are two parts to a certification.

The quality/safety standard

This is defined by UL, in their "White Book" documents. It's the equivalent of IEC and other foreign standards. These define how the product must be made, features, materials, flame resistance, toxic smoke, miles and miles of requirements.

This is UL's bailiwick. It's half their mission.

Certifying the product as complying with those standards

This certification is provided by any number of NRTL's. All of them are supposed to certify to the White Book standard.

ETL is an NRTL. So is UL (it's the other half of their mission).

They are supposed to be equivalent.

Obviously UL has a bit of a publicity edge since they were the national US testing lab for decades, owning both halves of the job until trade treaties obliged us to "open the market" on testing labs.

"Who is an NRTL" is decided by the US government, it's a side job of the US OSHA (Occupational Safety and Health Administration). Their list of NRTLs is widely depended on by many agencies in the United States and other countries. It is possible for a testing lab to lose their NRTL status and it has happened when they did not hold up quality standards.

Many report that UL holds a very firm standard, and manufacturers have called them "difficult to work with". I have my opinion about ETL's diligence, as they are the favorite of "cheapie" sellers. I also have my opinions about Amazon third party sellers. But those are neither here nor there.