SAN FRANCISCO — A U.S. Supreme Court opinion issued this week could make it more difficult for plaintiffs to prevail in certain wage-and-hour class actions, labor lawyers say.

In a unanimous decision, justices held in Integrity Staffing Solutions v. Busk that employers do not have to pay workers for time spent waiting in line for postshift security checks. The decision likely will affect pending employment cases such as Frlekin v. Apple, in which Apple retail workers are demanding compensation for time spent waiting to have their bags inspected after their shifts end. U.S. District Judge William Alsup of the Northern District of California had stayed the federal claims in that case pending a ruling in Busk.