Metanil yellow is a synthetic azo dye widely used in various industries. In the textile industry, it is employed for coloring fabrics such as silk, wool, and cotton, providing a vibrant yellow hue. It is also used in the paper and leather industries to impart color to products. Additionally, it serves as an acid-base indicator in analytical chemistry, exhibiting a color change from red to yellow between pH 1.2 and 2.3. In the food industry, it has been misused as an adulterant in spices like turmeric and sweets to enhance appearance, though this is illegal and hazardous due to its toxicity. Due to health concerns, its use in food and certain consumer products is strictly regulated or prohibited in many countries.