What Is an NRTL?
OSHA’s Nationally Recognized Testing Laboratory (NRTL) program helps verify that certain products used in the workplace have been tested and certified to applicable product-safety standards. The term NRTL certification refers to this testing and listing process and the resulting certification mark authorized by a recognized laboratory.
An NRTL is an independent organization recognized by the Occupational Safety and Health Administration (OSHA) to test and certify products within a defined scope. When a product meets the applicable requirements, the NRTL authorizes the manufacturer to apply its certification mark to the product, signaling independent verification that the product conforms to the relevant safety standard.
How NRTL testing and NRTL certification works
A manufacturer submits a product to an NRTL that is recognized for the applicable standard. Evaluation can cover construction, electrical components, wiring, temperature and heat behavior, wire and cable sizing, and other conditions that affect safe operation. If the product meets the standard, the NRTL lists or certifies it and authorizes the appropriate mark.
OSHA maintains a list of recognized labs and their scopes; that list shows which organizations are recognized for which standards and product categories. See OSHA’s NRTL program overview for more details.
Are UL, CSA, and ETL marks accepted under OSHA?
Common marks you’ll see on electrical equipment include UL, CSA, and ETL. What matters for compliance is whether the organization that issued the mark is recognized by OSHA for the specific product-safety standard and whether the product was certified within that recognized scope. OSHA treats recognized labs equally for a given standard; it does not give blanket preference to one over another.
UL LLC and CSA Group Testing and Certification Inc. are recognized NRTLs. The ETL mark is associated with Intertek Testing Services NA, another OSHA-recognized NRTL. Each organization uses its own mark to show that a product has been evaluated and certified to the applicable requirements.
Reading certification marks
Certification marks often include indicators that clarify the geographic or market scope of the listing. For example, CSA Group marks may include a US indicator, a C indicator, or both (C and US) to show whether the certification applies to the United States, Canada, or both. Always consider the mark together with the product listing or certificate—not just the logo alone—because the listing defines the standard and exact coverage.
Canto USA and CSA Group certification
Canto USA works with CSA Group Testing and Certification Inc. for applicable product testing and certification. CSA Group is recognized by OSHA as an NRTL and provides testing and certification services across many industries. For Canto USA, certification has included products within our RETRO LED Series and followspot product lines.
What product testing can cover
Testing depends on the product and the standard. For Canto USA products, testing has included items such as construction and physical integrity, electrical components and wiring, temperature and heat testing, wire and cable sizing, and conditions that could affect safe operation. The goal is to confirm that the product meets the applicable safety requirements for its intended use—not just that it operates.
Third-party NRTL certification testing is separate from Canto USA’s internal production quality-control process. Our internal testing includes functional, visual, and operational checks before products ship. For more on our internal quality and test process, see Quality control process: How Canto USA tests RETRO fixtures and followspots.
Certification follow-up and factory oversight
NRTL certification does not end with the initial listing. Certification organizations conduct ongoing factory inspections and reviews to ensure production continues to match the design and components that were originally evaluated. For Canto USA products covered by CSA certification, follow-up may include reviewing production records, components, and product samples.
This continuing oversight matters because changes to materials, electrical components, wiring, or construction can affect whether a product still conforms to its certified design.
How to verify an NRTL listing for a Canto USA product
- Have the product name and model available—this helps us and the certification body find the listing.
- Ask for the certificate or listing number from the manufacturer or sales contact; an NRTL can confirm whether that number is current and within scope.
- If you see a certification mark, check the associated listing or agency documentation rather than relying on the logo alone.
- If you need assistance, contact Canto USA’s sales team or your project representative so we can pull the appropriate listing or agency documentation for your project.
Frequently asked questions (brief)
Does a CSA, UL, or ETL mark guarantee local code compliance? Not automatically. The mark shows certification to a particular standard; local code officials determine compliance with codes and permit requirements in their jurisdiction.
Can Canto USA alter a certified product design? Any material change that affects construction, components, or electrical design should be reviewed with the NRTL so the listing remains valid. That is why follow-up factory reviews are part of certification.
Want certification documentation for a product?
If you need certification information for a particular Canto USA product, contact our sales team or your Canto USA project representative. Providing the product name and model number will help us identify the appropriate listing, certificate, or agency documentation for your project.
Related reading: see our post about RETRO Series installations and how Canto USA brought more component manufacturing in‑house for background on product updates and quality control.