Direct Red 23 (Congo Red) is a direct azo dye used in the textile industry for dyeing cotton, linen, and other cellulosic fibers, imparting a bright red color. It is typically applied in slightly alkaline conditions, offering moderate light fastness and potentially low wash fastness without fixing agents. Valued for its ease of application, it is suitable for products not requiring high durability, such as disposable or economical fabrics. Also used in paper printing, leather dyeing, screen printing, and artistic applications needing intense red shades. In laboratories, it serves as a model azo dye for studying degradation processes, wastewater treatment, and environmental remediation due to its visible color and stability. Not suitable for food or pharmaceutical use.