o-Toluidine chloride is primarily used in the synthesis of dyes and pigments, especially azo dyes, which are widely applied in the textile, leather, and paper industries for coloring. It serves as an important intermediate in the production of agricultural chemicals, including certain herbicides and pesticides. It is also utilized in the manufacture of rubber chemicals and curing agents for epoxy resins. Due to its reactivity, it plays a role in the development of pharmaceuticals and fine chemicals where aromatic amines are required as building blocks. Its use is generally restricted to controlled industrial settings due to toxicity and potential health risks.