Acid Red A is Dark red powder. Slightly soluble in acetone, soluble in ethanol, water and cellolytic (red). Acid Red A in the presence of concentrated sulfuric acid, it turns blue-violet, and after dilution, it turns yellow-brown precipitation; in concentrated nitric acid (red light yellow); in dilute sodium hydroxide The solution was reddish brown with a dark precipitate. When dyeing, the color of copper and iron ions is darker. Besides, Acid Red A with good dye discharge.