Mordant Orange 1 is primarily used as a dye in the textile industry, particularly for coloring wool, silk, and other protein-based fibers. It is a mordant dye, meaning it requires a mordant, such as aluminum, chromium, or iron salts, to fix the dye onto the fabric, ensuring colorfastness and durability. This dye is valued for its ability to produce vibrant orange hues that are resistant to fading from washing or exposure to light. It is also applied in dyeing leather and paper. Additionally, it has been utilized in biological staining applications, where it helps in the identification and study of specific tissues or cellular structures under a microscope. Furthermore, it serves as a pH indicator with a transition range from 10.0 (yellow) to 12.0 (red) and as a metallochromic indicator in analytical chemistry. Its stability and strong coloration make it a reliable choice in both industrial and scientific contexts.