American Airlines is changing vendors for its employee uniforms, after employees sued over health problems they allege were caused by the garments.

Thousands of flight attendants and crew members complained of symptoms ranging from caused hives, swollen faces, wheezing, vertigo, headaches and severe respiratory problems. A lawsuit filed against American Airlines and Twin Hill – the manufacturer of the uniforms – was filed in federal court last fall by the Association of Professional Flight Attendants (APFA), the union representing more than 25,000 AA flight attendants.

The National Institute for Occupational Safety and Health (NIOSH) issued a health hazard evaluation of symptomatic reactions believed to be tied to uniforms that states, "It is possible that textile chemicals in the (Twin Hill) uniforms or the physical irritant properties of the uniform fabrics have caused skin symptoms among some AA employees who wore the uniforms. Irritant and allergenic compounds were identified in some uniform garments, which could cause these skin symptoms."

American Airlines announced recently that it will now get uniforms for its 51,000 employees from Lands’ End, which also makes uniforms for Delta Air Lines.

The company expects testing on the new clothing to begin in October, with about 1,000 employees in a range of roles and locations trying out the uniforms. It will be about two years before the uniforms will be ready the company’s entire workforce.