"We take this very seriously," said Christopher Holschier, a spokesman for Fraport, the company which operates the airport. The company has said it will use the European Commission's findings to improve staff training.
The loss of Schengen Area status would be hugely damaging for Frankfurt's reputation and status as a hub, but police sources are confident that can be avoided, according to a report in Frankfurter Rundschau newspaper.
Federal police are responsible for security at the airport, but it is subcontracted to Fraport and I-SEC, an aviation security company based in the Netherlands.
The European Commission has declined to comment on the inspection or its findings, beyond confirming that it carries out regular checks on security at EU airports, and saying that member states are expected to act quickly on any shortcomings that are found.