Federal safety inspectors have concluded that the twisting, bending and long reaches that Amazon warehouse workers perform as much as nine times per minute put them at high risk for lower back injuries and other musculoskeletal disorders and constitute an unacceptable hazard.

As part of a larger investigation into hazardous working conditions, the Occupational Safety and and Health Administration announced on Wednesday it has cited Amazon for failing to keep workers safe at warehouses in Deltona, Florida; Waukegan, Illinois; and New Windsor, New York.

"While Amazon has developed impressive systems to make sure its customers' orders are shipped efficiently and quickly, the company has failed to show the same level of commitment to protecting the safety and wellbeing of its workers," said Assistant Secretary for Occupational Safety and Health Doug Parker.

The e-commerce giant faces a total of $60,269 in proposed penalties, the maximum allowable for a violation of the General Duty Clause of the Occupational Safety and Health Act, which requires employers to provide a workplace free from recognized hazards.

Amazon has 15 days to contest OSHA's findings.

"We take the safety and health of our employees very seriously, and we strongly disagree with these allegations and intend to appeal," said Amazon spokesperson Kelly Nantel in a statement.

"Our publicly available data show we've reduced injury rates nearly 15% between 2019 and 2021," Nantel added. "What's more, the vast majority of our employees tell us they feel our workplace is safe."

Parker noted that willful or repeated violations by an employer can lead to higher penalties. He said that there are no ergonomic-related violations in Amazon's history that put the company on track for the "severe violator program," but with further inspections, that could change.

In December, OSHA cited Amazon for more than a dozen recordkeeping violations, including failing to report injuries, as part of the same investigation.

Inspectors compared DART rates — days away from work, job restrictions or transfers — across the warehouse industry and at Amazon facilities, and found the rates were unusually high at the three Amazon warehouses.

At the Amazon fulfillment center in Waukegan, Illinois, where workers handle packages in excess of 50 pounds, the DART rate was nearly double the DART rate for the industry in general, and at the Amazon facilities in New York and Florida, it was triple.

The DART rate for the industry in general was 4.7 injuries per 100 workers per year in 2021, Parker said.

Inspectors also found that workers are at risk of being struck by falling materials unsafely stored at heights of 30 feet or higher at the Florida facility.

Should the government prevail, Amazon would be required not only to pay the fines but also to correct the violations, which Parker noted, could result in significant investments in re-engineering their processes to provide workers with a safer working environment.

Editor's note: Amazon is among NPR's recent financial supporters.