If you're manufacturing a product for sale in the United States, at some point someone is going to ask you for NRTL certification. Maybe it's a purchasing agent who won't place an order without it. Maybe it's a building inspector who flagged your equipment during installation. Maybe it's a retailer whose supplier requirements include a recognized safety mark.
What they're asking for is a product evaluation conducted by a Nationally Recognized Testing Laboratory — an organization that OSHA has determined is qualified to test products against established safety standards and issue certifications that carry legal standing in the US workplace.
What Is an NRTL?
NRTL stands for Nationally Recognized Testing Laboratory. NRTLs are private organizations — not government agencies — that have been evaluated and approved by OSHA to test and certify products to established safety standards. When an NRTL certifies a product, they're declaring that it has been tested and meets the requirements of the applicable standard.
OSHA maintains the NRTL program under 29 CFR 1910.7 and publishes a current list of approved NRTLs along with the standards each NRTL is authorized to certify against. NRTLs are approved for specific standards — not all NRTLs are authorized to certify all product types, which is why matching your product to the right NRTL matters.
Well-known NRTLs include UL (Underwriters Laboratories), CSA Group, Intertek (ETL), TUV SUD, and MET Laboratories, among others.
Why Does OSHA Require It?
OSHA's mandate is workplace safety. The agency's electrical safety standards — most notably 29 CFR 1910.303 — require that electrical equipment used in workplaces be listed, labeled, or certified by an approved organization. The NRTL program is how OSHA defines and enforces that requirement.
In practical terms: if electrical equipment is installed in a US workplace and it doesn't carry a mark from an OSHA-approved NRTL, it doesn't meet OSHA's definition of acceptable installation. An inspector can require it to be removed or shut down — which is exactly what a red tag represents.
The NRTL requirement covers a wide range of products used in commercial and industrial settings, including:
- Industrial control panels and factory automation equipment
- Commercial cooking equipment and appliances
- HVAC and refrigeration equipment
- Medical and dental equipment
- Lighting fixtures and electrical signs
- Motor-operated tools and machinery
- IT and data center equipment
How the Certification Process Works
| Step | What Happens | Who Is Involved |
| Standard determination | The applicable product safety standard(s) are identified based on the product type and intended market | Manufacturer + NRTL |
| Application and quotation | Manufacturer submits product information; NRTL provides scope and cost estimate | Manufacturer + NRTL |
| Testing | Product is evaluated against standard requirements, including any required destructive testing | NRTL laboratory |
| Review and decision | Test results are reviewed; deficiencies are communicated for correction if needed | NRTL engineer |
| Certification issued | If product passes, NRTL issues certification; manufacturer is authorized to apply the mark | NRTL |
| Follow-Up Services | NRTL conducts periodic factory inspections to verify ongoing compliance | NRTL inspector |
How to Choose the Right NRTL for Your Product
The OSHA website lists all current NRTLs along with the specific standards they're accredited to certify against. Your first step is identifying which standard(s) apply to your product — the applicable standard is typically determined by product category.
Once you know the applicable standard(s), verify that the NRTL you're considering is approved to certify against those specific standards. Other factors to consider:
- Technical expertise in your product category — some NRTLs specialize in certain industries
- Laboratory location and testing capacity — affects timeline and logistics
- Reputation and acceptance by your target customers and their AHJs
- Cost and turnaround time for your product type
PSC Works With All Major NRTLs
Product Safety Consulting has relationships with all major NRTLs and can help you identify the right certification path for your product, navigate the submission process, and address any technical questions that arise during evaluation. We've been doing this work since 1988 across every major product category. Reach out at productsafetyinc.com or call 877-804-3066.
Frequently Asked Questions
Q: Is NRTL certification the same as UL listing?
A: UL listing is one type of NRTL certification — UL is an NRTL. But UL is not the only NRTL, and NRTL certification is not synonymous with UL listing specifically. Products can carry certifications from CSA, ETL, MET, TUV, or any other OSHA-approved NRTL and meet the same requirements.
Q: Do I need NRTL certification if I'm only selling products to consumers?
A: OSHA's NRTL requirements specifically apply to workplace safety — equipment used in commercial and industrial settings. Consumer products may not fall under OSHA's requirements, but may still need to meet other standards that effectively require NRTL certification or equivalent. Many major retailers require NRTL marks regardless of OSHA applicability.
Q: Can foreign manufacturers get NRTL certification for products sold in the US?
A: Yes. NRTL certification is available to manufacturers regardless of where they're located. Foreign manufacturers submit their products to the NRTL the same way domestic manufacturers do. Equipment already installed in the US without certification is addressed through a field evaluation rather than a standard factory certification program.
Q: How do I know if a certification mark on a product is from a legitimate NRTL?
A: Cross-reference the mark against OSHA's current list of approved NRTLs and the marks they're authorized to use. If you encounter a certification mark that isn't on the OSHA list, it may not constitute an acceptable NRTL certification.
Q: Do NRTL certifications expire?
A: The certification itself doesn't have a fixed expiration date, but it can be suspended or withdrawn if the manufacturer fails to maintain compliance. Additionally, when the applicable standard is revised, the NRTL will notify certified manufacturers of the changes and the requirements for updating the certification to the new standard version.
Product Safety Consulting, Inc. | Bensenville, IL | 877-804-3066 | productsafetyinc.com