If you’re developing an electrical product that plugs into the main socket for the North American market, you’ll almost always need to go through a certification process for electrical safety. And the most common certification marks are UL, ETL, and CSA.
Even if your product is only sold in the USA and it is not for use in a workplace (meaning that OSHA requirements don’t apply), the retailers, distributors, and insurers expect to see such a certification.
In this article, we want to try and simplify the three key steps, plus two “pre-steps” that can save you from costly mistakes, to follow.
Pre-Step 0: Design with the Standards in Mind
Before testing, you need to ensure the design of the product (including the sourcing of critical components) complies with applicable requirements. Here are examples of relevant technical standards:
- IEC 62368-1 for audio/video and ICT equipment
- IEC 60335-1 the rest of the IEC 60335 family for electrical household appliances
The issue is that few design & sourcing engineers are deeply familiar with these standards. And it’s not necessarily a must if you follow the next pre-step…
Pre-Step 0.5: Pre-scan/pre-test
Before committing to final engineering prototypes, and if possible before investing in tooling, ask a qualified testing lab to conduct a pre-scan/pre-test on a functional prototype. If possible, pick the same lab that will do the rest of the test (and issue the certification) later on.
This often uncovers compliance issues relatively early. How early depends on your product design. For example, if you plan to spend 100 engineering hours miniaturizing a module, make sure you have picked pre-certified critical-to-compliance components. And that those components’ certifications are against the right standard. The lab can probably help you de-risk that aspect of the design.
Step 1: Verification of the Product Design and BOM
Now, you have sent work-like & look-like samples as well as design files to the lab, and they are going to start to work.
Typically, the first formal stage of the UL/ETL/CSA certification process is verifying your design (e.g. electrical diagram, construction…) and safety-critical elements of the bill of materials (BOM). The lab reviews components and documentation. If an issue arises:
- Parts may need re-sourcing.
- Engineers may need to adjust their work and then prepare new samples.
Step 2: Product Testing
Next, the testing lab subjects your product to rigorous testing. If it passes, you move forward. If it fails, the design must be modified and new samples need to be tested.
This iterative loop is quite common if you have not followed both ‘pre-steps’, so bear that cost in mind when budgeting.
Step 3: Factory Audit
The final stage of the UL/ETL/CSA certification process is a factory audit, carried out by the certification body’s own inspectors (e.g. a local Intertek office for ETL), and focuses only on ensuring the factory can consistently produce the certified product*.
Inspectors check that:
- Only the approved BOM and key components are used.
- Production methods match those tested (e.g. soldering, grounding, insulation).
- The certification mark is applied correctly.
*Regular follow-up inspections are required to maintain certification.
Risks to Watch Out For
- Component lock-in: Once the factory purchases components, changing the BOM could mean scrapping materials. That’s especially tricky with long-lead-time components.
- Ordering too soon: If you commit to production before testing is complete, you risk making products that later need redesigns.
To reduce risk, wait until the lab has reviewed the design and BOM, and until most tests are complete, before placing pre-production orders.
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Read more about related requirements in the USA:
How To Get a UL Certification Mark (or Equivalent) on Electrical Products?
FAQs
What are UL, ETL, and CSA?
They are independent organizations that test and certify products for safety in North America:
- UL (Underwriters Laboratories): The most widely recognized U.S. safety certification body.
- ETL (from Intertek): A global testing and certification company.
- CSA (Canadian Standards Association): Based in Canada, but also recognized in the U.S. Certification proves compliance with Canadian and U.S. safety standards.
Does our product need all three certifications?
No. You don’t need UL, ETL, and CSA together. One mark is enough to demonstrate compliance, as they are considered equivalent under North American safety standards.
Is UL/ETL/CSA certification legally required?
In Canada, if your product plugs into the mains, our understanding is ‘yes’. In the USA, our understanding is ‘yes if it may be used in a workplace’. But in practice, certification is essential: most retailers and insurers won’t accept uncertified products.
What’s the difference between UL, ETL, and CSA?
All three are recognized marks in North America. ETL and CSA are equivalent to “UL Listed” in demonstrating compliance with safety standards.
How long does certification take?
Depending on the product’s complexity, documentation quality, and test results, certification can take anywhere from 4 weeks to 4 months. Most electromechanical products fall in the 8–16 week range.
Can I skip the factory audit?
No. The audit is mandatory, and confirms the factory can reliably manufacture compliant products.
When should I start certification?
When you have samples that are identical to the products that will come out of production. If some parts are to be made with tooling, for example, the tooling must be made first. Please also note that pre-testing and design reviews should take place much earlier than that and often save major costs.
