A dye composition for hair dyeing containing an azo dye as a main component was found to indicate negative in the Ames test by specifying impurities that indicate positive in the Ames test among impurities in the azo dye contained in the dye composition for hair dyeing containing the azo dye as a main component, by analyzing purification methods for the purpose of removing the impurities, and by carrying out purification by a specific method in order to develop a purification method for the dye composition for hair dyeing containing the azo dye as a main component and proving negative in the Ames test and to provide the dye composition for hair dyeing that is produced by applying the purification method and indicates negative in the Ames test.開發以偶氮染料作為主成份在安氏測試法為陰性之染髮用染料組成物之精製方法,為了提供適用於該精製方法所製造之在安氏測試法呈現陰性之染髮用染料組成物,在以偶氮染料作為主成份之染髮用染料組成物所含有的偶氮染料中的雜質之中,確定出在安氏測試法中呈現陽性之雜質,探討以除去該雜質為指標的精製方法,發現靠著藉由特定的方法的精製,以偶氮染料為主成份之染髮用染料組成物在安氏測試法中呈現陰性。
