ETL VS UL: What is the Difference?

​Underwriters Laboratories (UL) and Electrical Testing Laboratories (ETL) are both NRTLs approved by OSHA for testing and certifying electronics and electrical products. With over 100 years of operation, both organizations are trusted by many countries to conduct tests on products and issue certificates for approved products. However, despite their similarities, some companies prefer one over the other due to the differences in their strengths and weaknesses.​

In this post, we will compare and contrast ETL and UL to provide information that can help companies choose the best certification company for their needs.​

Part 1: What are ETL & UL Organization?

1.1 Underwriters Laboratories (UL)

Underwriters Laboratories (UL) is a global science company that operates in over 100 countries. Established in 1894, UL is committed to ensuring public safety by setting standards and testing, inspecting, and certifying products across different categories. Headquartered in Northbrook, Illinois, UL is one of the most reliable testing laboratories and has more than 1500 approved standards for testing products.

UL is approved by the Occupational Safety and Health Administration (OSHA) as a Nationally Recognized Testing Lab for a wide range of electrical products. With their extensive experience and expertise, UL is considered a trusted name in product testing and certification, providing companies with the assurance that their products meet the highest safety standards.

1.2 Electrical Testing Laboratories (ETL)

The Electrical Testing Laboratories, formerly called lamp testing bureau, is a UK-based company that is currently a division of Intertek Testing Laboratories. It started in early 1896 when Thomas Edison established the lamp testing bureau. The Occupational Safety and Health Administration (OSHA) also approved Electrical Testing Laboratories.

It tests and certifies products of different categories; however, the laboratory does not create its standards. It abides by the standards directed by other agencies like Underwriters Laboratories (UL), the American Society for Materials and Testing (ASMT), and the American Society of Mechanical Engineers (ASME). An ETL certification is given when Intertek approves a product.

Part 2: UL VS ETL – What are the Differences?

The main difference between Underwriters Laboratories certification and Electric Testing Laboratories certification is that UL develops some of the standards it uses to test and inspect products alongside other standards mandated by other regulatory agencies.

However, ETL listed does not make its standards but only uses the standards required by other agencies, including Underwriters Laboratories. 

Even though UL and ETL were established around the same period, UL has gained more popularity and is more recognized than ETL. Users who criticize ETL claim that UL is more rigid. This adds dignity to products that have a UL certificate.

Another difference is that conducting a UL test is more expensive than ETL. However, generally speaking, certification is expensive, and as a result, most companies mostly send product samples to be sold to companies that value high standards for testing.

Lastly, the popularity of UL certification, as opposed to the ETL certification, results in too many customers hence, a longer waiting list. Getting a UL certification takes a longer time compared to an ETL certification. Despite this factor, most producers still favor UL over ETL.

Part 3: Why You Need to Certify Your Product?

Product certification is mandated in the U.S. Seeing a certification mark from a reliable testing lab on a product ensures its safety and dependability. It is the process of testing and mainly certifying electrical products through approved testing laboratories to ensure that they are safe for customers.

In the United States, the NRTLs are the approved third-party testing laboratory for products. Successfully passing your product through tests in an approved laboratory boosts its confidence and convinces customers of its reliability. Some retailers or wholesalers will even refuse to stock electrical products that do not have a certification mark.

Bonus Tips: Steps Taken to Certify a Product

After a sample electrical product is sent to a testing laboratory, these are seven steps taken to test and certify the product.​​

  • Reviewing Safety Design and Construction Features: Gap analysis is taken, and the laboratory will check the product's overall compliance with the set regulations.

  • Product Safety Testing: After this, the product is tested or confirmed that no dangers exist during its usual operation. A test plan will be created depending on how the product will be used in the field. This will serve as a guide when deciding on the test parameters to use.

  • Project Review: The analysis so far has been reviewed. Every product can fall into two categories.

  • Findings Report: If the product is found to not comply with the construction features or test results, the engineer will present a report that will summarize the problem.

  • Certification Report: If the product passes the first two stages, the engineer drafts a report that they will use subsequently to draft the factory inspection process.

  • Factory Inspection: The production facility will be inspected to ascertain that safety standards were followed during production and to confirm that the product is manufactured according to the policies and procedures. The factory will scrutinize samples of the certified product with the records of the production processes.

  • Report and Certificate Issued: After the draft has been reviewed and confirmed by all engineers involved in the inspection, a certification report and certificate of compliance will be issued to the product.


Certification of electrical products is done in the United States by Nationally Recognized Testing Labs (NRTLs) overseen by the Occupational Safety and Health Administration (OSHA) to ensure the safety of a wide variety of electrical products used in the country. Two popular NRTLs are Underwriters Laboratories(UL) and Electrical Testing Laboratories (ETL).

Both testing laboratories are approved laboratories for testing, investigating, and approving electrical appliances according to the guidelines of some regulatory agencies. The aim is to guarantee that these products are non-hazardous for use and to ensure they pass the necessary safety parameters.

You can choose to get a UL certification mark or an ETL certification mark. Though UL has gained more recognition than ETL, there is little to no difference as both put electrical products through rigorous testing procedures.​


Sign up to our newsletter to receive LEDVANCE product launches, company news and promotion and contest information straight to your inbox.