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.
