An employee of Roy Rock, LLC, a New Jersey concrete and masonry construction company, was injured when his hand was caught in a machine that bends and cuts reinforcing steel bar, known as “rebar.” Following the incident, the Occupational Safety and Health Administration issued Roy Rock a citation alleging a serious violation of a provision of the Concrete and Masonry Construction standard, 29 C.F.R. § 1926.702(j)(1), which requires potentially hazardous energy sources to be locked out and tagged during equipment maintenance or repair. Administrative Law Judge Carol A. Baumerich affirmed the citation. For the following reasons, we conclude that the Secretary has failed to establish § 1926.702(j)(1)’s applicability here. Accordingly, we reverse the judge’s decision and vacate the citation.