Direct Black 22 is a direct dye used primarily in the textile industry for coloring cellulosic fibers such as cotton, linen, and other cellulose-based fabrics. It binds well to fibers without the need for a mordant, providing a uniform deep black color with moderate wash fastness. It is commonly applied in the dyeing of industrial textiles, including workwear, uniforms, and covers, where cost-effective deep shading is required. Additionally, it is used in certain printing inks, leather dyeing processes, and occasionally in biological staining for microscopy to enhance contrast in tissue samples. Due to its aromatic structure, which may degrade to aniline (a toxic substance), careful handling, usage control, and proper wastewater disposal are essential.