Nurses have complained of skin irritation caused by new uniforms which are used by two Welsh health trusts.
Patients will be able to identify different grades of nurses by the new all-Wales uniforms, it is hoped.
But staff welfare is of paramount importance a Welsh Assembly Government spokesman said, who described the development as disappointing.
It is essential that any problem must be reported, the director of the Royal College of Nursing in Wales said.
As part of an assembly government initiative the uniforms have been piloted in the Hywel Dda Health Board, which has succeeded Carmarthenshire Local Health Board and Betsi Cadwaladr University Health Board in north Wales.
"A minority" of nurses have reported problems of skin irritation, but the assembly government expressed concern.
"As only a minority of staff have reported a problem, we have sufficient supplies of alternative uniforms for use," said a spokesman.
"We are also working in partnership with RCN [Royal College of Nursing] and UNISON [union] to address any concerns as quickly as possible."
There had been extensive testing, quality control and trials carried out on the fabric used in the uniform, the spokesman added.
Further tests should be carried out on the uniforms if there are more complaints, Tina Donnelly, the director of Royal College of Nursing in Wales said. She added that it was important people reported any problems to the occupational health department.