Listed. Equipment is listed if it is of a kind mentioned in a list that:
(1) Is published by a nationally recognized laboratory that makes periodic inspection of the production of such equipment, and
(2) States that such equipment meets nationally recognized standards or has been tested and found safe for use in a specified manner.
29 CFR § 1910.399
Acceptable. An installation or equipment is acceptable to the Assistant Secretary of Labor, and approved within the meaning of this subpart S: