In North America (USA and Canada) for several products there is mandatory requirement for products to be approved by NRTL’s (Nationally recognised test laboratories). For example, As per OSHA (Occupational Safety and Health Administration) in the US, it is mandatory for Electrical and Electronic equipment used in a workplace to be approved and tested via a NRTL.
Organisations currently recognised by OSHA as NRTL's
• Canadian Standards Association (CSA) (also known as CSA International)
• Communication Certification Laboratory, Inc. (CCL)
• Curtis-Straus LLC (CSL)
• FM Approvals LLC (FM) (formerly Factory Mutual Research Corporation)
• Intertek Testing Services NA, Inc. (ITSNA) (formerly ETL)
• MET Laboratories, Inc. (MET)
• NSF International (NSF)
• QPS Evaluation Services Inc. (QPS)
• SGS U.S. Testing Company, Inc. (SGSUS) (formerly UST-CA)
• Southwest Research Institute (SWRI)
• TUV Rheinland PTL, LLC (TUVPTL)
• TÜV SÜD America, Inc. (TUVAM)
• TÜV SÜD Product Services GmbH (TUVPSG)
• TUV Rheinland of North America, Inc. (TUV)
• Underwriters Laboratories Inc. (UL)
Note: Some of these are limited in scope of the type of products they will certify.
An up to date list can be viewed here.
The process for NRTL approval in general tends to be long and extremely expense. The product and the relevant documentation must be submitted for testing. After a successful test a factory audit will be scheduled. On conclusion of testing and factory audit you will be issued with the test report and test certificate.
You will also be issued with the license to affix the NRTL's certification mark on your product. You will be issued a license which will allow you to affix the NRTL's certification mark on your product. You will also be issued a licence number or certification number to affix on your product. This number can be used to track the scope of your certification at any time on the web.
The continued costs
Depending on the NRTL you choose there will 2 or 4 factory audits per year. Each audit will last a day. These audits will continue until the time you wish to discontinue the certification. In addition to the continued factory audits there will also be an annual licensing fee. This fee will depend on the number of products covered under the scope of the certification and will continue until you wish to discontinue all certifications.