Federal investigators at the Occupational Safety and Health Administration (OSHA) discovered that the nation’s largest air carrier “retaliated” against flight attendants who reported falling ill because of toxic fumes. The government body has called on American Airlines to pay $6,837 in penalties for violations of the 1970 Occupational Safety and Health Act.

It initiated an investigation on August 2 after concerns were raised by whistleblowers, OSHA said in a statement on Wednesday. A Department of Labor spokesperson told Newsweek that “all flight attendants/crews were subject to these policies, which led to several complaints of retaliation being filed with OSHA.”

Flight attendants alleged that the airline docked attendance points for complaining about their illnesses and discouraged them from making workplace injury and illness reports.

“Our investigation found that the flight attendants engaged in protected activities when they reported illnesses related to jet fuel fumes seeping into the aircraft cabin,” said Timothy Minor, OSHA Area Director in Fort Worth, Texas, where the airline is based.

In a letter to the airline, Minor noted that American Airlines had “discriminated against employees” for reporting workplace illness or injury on at least one occasion last summer.

The OSHA chief also stated that on three separate occasions in July and August 2022, employees were charged one or two attendance points—which are used to penalize workers for lateness or absence—for reporting an illness “that resulted from a workplace fume event.”

Minor told American Airlines that the violations were ones “you do not contest” and ordered it to give evidence of “appropriate corrective action,” which could include results of air sampling tests.

The air carrier—which the Department of Labor estimates employs around 109,000 workers, of which 24,000 are flight attendants—now has 15 working days to comply with the OSHA orders, request a meeting with Minor, or contest the findings.

A Department of Labor spokesperson said that OSHA had previously settled several complaints regarding the reporting of work-related injuries or illness with the airline, “with American Airlines agreeing to fix the problem so that future retaliation for reporting work-related injuries/illnesses did not take place.”

“The practices were not corrected and the citations were issued for new instances of retaliation for reporting work-related injuries/illnesses,” the department said.

A 2008 report by the House Committee on Education and Labor said that work-related injuries in the U.S. are “chronically and even grossly underreported.” It suggested that employers had “strong incentives” to underreport workplace illness and injury, including fewer OSHA inspections and lower compensation insurance premiums.

“Federal law protects workers’ rights to voice workplace safety and health concerns without the fear of retaliation,” said Minor. “When employers punish employees for doing so, they create a chilling effect that may stop workers from reporting future issues, putting their health and well-being, and that of co-workers, at risk.”

An American Airlines spokesperson told Newsweek: “The safety of our team members and customers is always American’s top priority. We are reviewing the findings of the OSHA investigation.”

Update 01/05/23, 1:54 p.m. ET: This article was updated with comment from the Department of Labor.

Update 01/05/23, 12:28 p.m. ET: This article was updated with comment from American Airlines.