AUGUSTA, Maine (AP) — The U.S. Postal Service is facing $430,000 in fines for “willful and repeated” electrical safety violations at a processing and distribution center, the U.S. Department of Labor said Monday.

The Occupational Safety and Health Administration began investigating the Southern Maine Processing and Distribution Center in Scarborough in response to worker complaints.

The investigation by OSHA inspectors from the Augusta office found that postal workers were exposed to electric shock, arc flashes and arc blasts from mail-processing equipment, the Labor Department said.

David Michaels, the assistant labor secretary for OSHA, said their bosses failed to prepare the workers “with the necessary knowledge and skills” to work with equipment with live electrical parts.

“The Postal Service knew that proper and effective training was needed for the safety of its workers but did not provide it,” Michaels said in a statement.

The department proposed six “willful” citations, which are defined as violations committed with plain indifference to or intentional disregard for employee safety and could bring $420,000 in fines.

No injuries were reported from those alleged violations.

The Postal Service defended its safety record and said it will review OSHA’s concerns “and make the necessary adjustments to ensure a safe working environment for our employees,” said the spokesman for its Northern New England District, Tom Rizzo.

He declined to say if the service would appeal.