The Occupational Safety and Health Administration said Thursday it issued the citations over concerns involving machine guarding, electrical issues, trip-and-fall hazards, blocked exits and storage of oxygen and acetylene cylinders at the Chicago airport.

American has 15 working days to respond to respond to the allegations or the penalties become final, Labor Department spokesman Brad Mitchell said.

"This is a very significant penalty being proposed," Mitchell said. "The average safety penalty is usually well below $50,000."

OSHA inspected the airline's operations at O'Hare after reviewing its occupational injury and illness data.

American spokeswoman Mary Frances Fagan said the airline's workplace safety record overall - and particularly at O'Hare - has improved significantly in the past two years. The airline already has fixed most of the issues noted in the inspection and is working to address the rest, Fagan said.

American could pay the proposed fines, file an appeal with an independent board or ask for a meeting with the local OSHA director, Mitchell said.

American is a subsidiary of Fort Worth, Texas-based AMR Corp.