The Food and Drug Administration on Wednesday released a scathing inspection report that notes unsanitary conditions and other serious failures at the Emergent BioSolutions manufacturing plant in Baltimore that ruined 15 million doses worth of raw Johnson & Johnson coronavirus vaccine.

The 12 pages of findings portray a plant with systemic problems, some of which echo concerns cited in a 2020 inspection report, including poor training of workers.

In the latest check, which began last week after the contamination, inspectors found that medical waste was improperly handled. Sensitive work areas had peeling paint and black and brown residue on walls.

Through a review of security camera footage, the FDA documented workers repeatedly failing to follow procedures to prevent cross-contamination of various vaccines being manufactured there.

The raw batches of Johnson & Johnson vaccine were ruined in March in a cross-contamination incident that involved ingredients from AstraZeneca’s coronavirus vaccine. The episode has disrupted Johnson & Johnson’s manufacturing plan for the United States, as well as AstraZeneca’s.

Both vaccines use a harmless virus to trigger coronavirus immunity in the human body after being injected. The live virus can spread during manufacturing, and careful handling is required.

Emergent, a contract manufacturer, is so far Johnson & Johnson’s only U.S. production facility for raw vaccine substance. But it has not been certified to manufacture the vaccine by the FDA. No vaccine made there is permitted to be used for shots in patients, and vaccine that has already been put into vials and prepared for shipment is under quarantine.

“We will not allow the release of any product until we feel confident that it meets our expectations for quality,” the FDA said in a news release Wednesday.

Vaccine manufacturing plants must be vigilant about the potential for cross-contamination, specialists said.

“Cross-contamination is serious since if undetected, it could lead to significant adverse medical events,” said Peter D. Smith, a former FDA investigator and manufacturing inspections official who is a consultant at Smith GMP Consulting in Rhode Island. He reviewed the FDA inspection report at the request of The Washington Post.

“FDA found many avenues of potential cross-contamination including handling of waste, improper disinfection practices, and improper handling of material containers,'' he said. “These problems appear to be related to failure to follow procedures and lack of proper training.”

With the production crisis at Emergent continuing to unfold, Johnson & Johnson has backed off pledges to deliver 24 million doses to the government by the end of this month. It said Wednesday that it will not speculate on whether the problems at Emergent will hamper its commitment to deliver nearly 100 million doses by the end of May.

Johnson & Johnson said it was adding 30 experts in manufacturing, technical operations and quality to be on site at Emergent, including heads of quality and operations. But Emergent and Johnson & Johnson did not provide a timetable Wednesday on when problems at the plant would be resolved.

"While we are never satisfied to see shortcomings in our manufacturing facilities or process, they are correctable and we will take swift action to remedy them,'' Emergent said in a statement.

It called its employees, who are cited multiple times in the FDA report for not following procedures to prevent cross-contamination of vaccines, “a heroic workforce who have stepped up to work 24/7 to ensure vaccines will be produced with the highest quality and quickly available to fight this pandemic.”

The Emergent troubles are unrelated to a pause in Johnson & Johnson shots called by the Biden administration while data is gathered on extremely rare blood clots that have been associated with the vaccine. A CDC panel is expected to revisit that pause on Friday.

The FDA report for the first time suggests a potential cause of the batch error: A worker who prepared growth media for the vaccine did not follow procedures to prevent cross-contamination. Video surveillance showed the unidentified worker wearing a protective gown and foot protection in a hallway before entering another area wearing the same gear.

The FDA cited Emergent for its “failure to conduct thorough investigations into unexplained discrepancies.” The company did not investigate the movement of employees through the plant and also did not thoroughly consider whether the storage of materials for both vaccines could have contributed to the contamination, the FDA said.

Even after the contamination, the company performed only routine cleaning and did not take additional decontamination steps, the inspectors found.

“This is a very scathing report in terms of the capability of Emergent to be able to safely manufacture an injectable medicine,” said John Avellanet, a consultant who advises companies on FDA compliance and is managing director at Cerulean Associates, and who also reviewed the inspection report at the request of The Post. “Not only did Emergent management allow this to occur, why did J & J not pick up on it?”

He said it typically would take months to correct the violations, although he said the timeline could be compressed in a pandemic emergency.

Johnson & Johnson said it did have company staff at all of its contract manufacturers monitoring test runs and quality checks. “It was this quality control process that identified one batch of drug substance that did not meet quality standards at Emergent,” Johnson & Johnson spokesman Jake Sargent said in an email.

In another finding, FDA inspectors said a review of security camera footage showed employees failing to follow procedure in the handling of medical waste. The footage showed employees using their gloved hands to pack medical waste into bags, dragging medical waste along corridors, and allowing bags of medical waste to come into contact with walls. They also dropped protective gowns on the floor of a warehouse area, with raw vaccine ingredients nearby.

The FDA report cited multiple instances of workers failing to document, as required, when they put on a gown, took off a gown and showered.

Johnson & Johnson announced on April 3 in response to Emergent’s problems that it would take a more direct, hands-on approach to vaccine production there. On Wednesday, the company said it would “redouble” efforts to get the facility back on track.

“Johnson & Johnson will exercise its oversight authority to ensure that all of FDA’s observations are addressed promptly and comprehensively,” the company said in a news release.

The government had seen warning signs about Emergent a year ago, before the company received $648 million from the federal government to add manufacturing capacity for coronavirus vaccines. An inspection report at the time found that employees had not been properly trained. Records were not adequately secured. Established testing procedures were not being followed. And a measure intended to “prevent contamination or mix-ups” was found to be deficient.