A pair of American Airlines flight attendants have filed a class action suit against the manufacturer of “dangerous” staff uniforms, alleging that they and thousands of other employees have suffered serious health problems since it began supplying the clothing last September.

In a suit filed in the US District Court for the Northern District of Illinois Eastern Division on 2 August, plaintiffs Thor Zurbriggen and Dena Catan accuse clothing manufacturer Twin Hill Acquisition of providing “unsafe and unreasonably dangerous” uniforms to American Airlines cabin crew, including attendants, pilots and other service agents.

The petitioners reiterate complaints already aired by the Association of Professional Flight Attendants union, which says more than 3,500 of its members have complained that the uniforms cause a variety of health problems, ranging from rashes and headaches to fatigue and respiratory problems.

Twin Hill said in a statement that tests it carried out showed that the uniforms contained no materials that could cause any health problems.

“Nothing in the complaint filed by two American Airlines flight attendants changes the fact that there is absolutely no evidence linking any of the symptoms alleged to our uniforms,” the company said.

Catan said she began experiencing migraines after wearing the new uniform, while Zurbriggen said he has suffered eye and throat sores, as well as fatigue and rashes since last November, when he first started wearing the uniform.

Both petitioners said their health problems continued even after their uniforms were replaced, because they remained in close proximity to co-workers who also wore the Twin Hill uniforms. They estimate that up to 7,000 staff members have suffered health problems.

“One conclusion that is clear, however, is the new uniforms are causing these health problems. That is the only possible conclusion given that the thousands of American Airlines flight attendants and pilots began reporting serious adverse reactions only after the new uniforms were introduced,” the plaintiffs said in the suit.

The pair are claiming damages for personal injury and have also asked the court for injunctive relief to block the continued sale of the uniforms and to order the recall of those currently in use. They have also asked the court to establish a medical monitoring fund, so that the health of airline employees can be scrutinised to ensure that everyone affected is adequately compensated.

American Airlines told the LA Times that all of its employees were entitled to request alternative uniforms if they wished.

“We would never ask our team members to wear an unsafe uniform,” a spokesperson for the airline said.

American Airlines and Twin Hill have already announced that they will end their partnership once their existing contract expires in 2020.