BALTIMORE (AP) – The Baltimore factory contracted to make Johnson & Johnson’s COVID-19 vaccine was dirty, didn’t follow proper manufacturing procedures and had poorly trained staff, resulting in contamination of material that was going to be put in the shots, U.S. regulators said Wednesday.

The Food and Drug Administration released a statement and a 13-page report detailing findings from its recent inspection of the now-idle Emergent Biosciences factory.

Agency inspectors said a batch of the bulk drug substance for J&J’s single-shot vaccine was contaminated with material used to make COVID-19 vaccines for another Emergent client, AstraZeneca. That batch, reportedly enough to make about 15 million J&J vaccine doses, had to be thrown out.

Other problems cited in the inspection report were peeling paint, black and brown residue on floors and walls in the factory, inadequate cleaning and employees not following procedures to prevent contamination.

Both Emergent and Johnson & Johnson said Wednesday that they are working to fix the problems as quickly as possible. Nothing made at the factory for J&J has been distributed yet.

At the moment, use of the J&J vaccine is on hold in the U.S. as government health officials investigate its connection to very rare blood clots. The nearly 8 million doses of J&J vaccine that had been used in the U.S. came from European sources.

The Baltimore factory halted production late last week at the request of the FDA. The agency hasn’t given emergency approval to the factory, which is needed before any vaccine material made at the factory can be distributed.

All the bulk vaccine substance Emergent has made is being stored and will undergo additional testing by the FDA, the agency said.