In accordance with OSHA Safety Standards, any product used in the workplace must be approved by a Nationally Recognized Testing Laboratory (NRTL). This is needed to ensure that products can be used safely in the workplace. The NRTL approval applies to those products that are used in the workplace that are subject to OSHA’s jurisdiction. This includes many private employers in the USA. This also includes most Federal Government places of employment.
An NRTL is a private organization that OSHA has recognized as meeting the legal requirements in 29 CFR 1910.7. The recognition is an acknowledgement that an organization has the necessary qualifications to perform safety testing and certification of the specific products covered within its scope of recognition. An NRTL performs independent safety testing and product certification. Each NRTL must meet the requirements as set for by OSHA in the NRTL program. While the NRTL program is applicable to product safety within the USA, the NRTL itself can be located in other countries. All NRTLs test products according to the same requirements and test standards such as ANSI, UL, CSA, NSF, and many others. The OSHA recognition process is the same for all organizations.
Safety testing by an NRTL will ensure that a representative unit of a particular product has met all applicable safety requirements for its product category. The NRTL must also organize and operate a product certification program that includes listing, labeling, and follow-up inspection programs. In addition to the tested product, the NRTL must ensure that all manufactured units of the product have fulfilled all necessary safety requirements. OSHA does not perform any product approvals but relies on NRTLs to do this work. As a result, OSHA can accept products "properly certified" by the NRTL which means:
OSHA's current list of NRTLs includes UL, CSA, ETL, etc.
In the eyes of OSHA and the US Government, all NRTLs are considered equal and a product certified by any one of the recognized NRTLs should be accepted by an Authority Having Jurisdiction (AHJ) on the State level.
An NRTL will work with manufacturers to test and certify products. After successful testing of a product, the NRTL will issue formal certification which permits the manufacturer to apply the NRTL’s registered certification mark or symbol on all the units manufactured. This certification mark on the product is important in that it represents that the product has been tested and certified by the NRTL. This safety certification is product-specific; compliance may not be assumed across a manufacturer’s entire line of products without subsequent individual testing and certification. The OSHA web page shows the certification marks generally used by each NRTL. One of these linked marks will appear on product labeling with a reference to the standard that the product was tested against, and will not typically reference “NRTL” directly. The mark is again product and test standard-specific.
Each NRTL has a scope of accreditation, which will vary between NTRLs. The scopes of accreditation for NRTLs are available from the OSHA web page. The NRTL must test and use a US based test standard that is developed and maintained by a USA standards developing organization. International test standards may be used if they have been harmonized to USA requirements by a USA standards developing organization. NRTLs have been recognized for more than 600 product safety standards.
The European Union has the CE mark to indicate safety requirements as being met on equipment. The European Union CE mark is not related to the requirement for product safety in the United States. In the USA, equipment that is used in the workplace is required to be safety listed and approved by an NRTL. The NRTL safety mark provides the recognition that the equipment has been tested and certified.