Federal regulators on Wednesday issued highly critical findings from their inspection of a Baltimore plant that was forced to throw out up to 15 million doses of Johnson & Johnson’s coronavirus vaccine and ordered to temporarily stop all production.

The Food and Drug Administration cited a series of shortcomings at the massive plant, which is operated by Emergent BioSolutions. The inspection was triggered by reports that Emergent workers had contaminated a batch of Johnson & Johnson doses with the virus used to make AstraZeneca’s vaccine, which is also manufactured there.

The violations included failure to properly disinfect the factory and its equipment, as well as failure to follow procedures designed to prevent contamination of doses and to ensure proper strength and purity of the vaccine manufactured there. In a 12-page report, the inspectors cited a total of nine violations, ranging from the design of the building to improperly trained employees. The inspection was finished on Tuesday.

In a statement, the F.D.A. noted that it has not authorized Emergent to distribute any doses of Johnson & Johnson vaccine, and that no vaccine manufactured at the plant has been released for use in the United States.

AstraZeneca’s vaccine is not yet authorized for use in the United States, and all the Johnson & Johnson doses that have been administered in the country so far were manufactured overseas. At the agency’s request, all production at the factory has been halted.

“We will not allow the release of any product until we feel confident that it meets our expectations for quality,” the statement from Dr. Janet Woodcock, the F.D.A.’s acting commissioner, and Dr. Peter Marks, the agency’s top vaccine regulator, said.

The agency said it was working with Emergent to fix the problems.