Nationally Recognized Testing Laboratory (NRTL)
OSHA recognizes a private sector organization as a NRTL, which designates that the organization has met the necessary qualifications specified in the regulations for the Nationally Recognized Testing Laboratory Program. The NRTL determines that specific equipment and materials meet consensus-based standards of safety, to assure that the products are safe for use in the U.S. workplace.

In the U.S. there are many municipalities that have laws, codes or regulations which require a product to be tested by a NRTL. Companies must comply with OSHA requirements applicable to their operations.

Required NRTL Approval
Electrically powered industrial trucks used in hazardous areas are required by OSHA to be approved by a NRTL. Underwriters Laboratories (UL) is the largest and oldest NRTL in the United States. UL is recognized by OSHA as a NRTL for over 600 Product Standards including UL 583, UL 1203 and UL 1604.

OSHA's NRTL Program website