Trace constit. of essential oils 2-Naphthol is a colorless crystalline solid and an isomer of 1-naphthol, differing by the location of the hydroxyl group on naphthalene. The naphthols are naphthalene homologues of phenol, with the hydroxyl group being more reactive than in the phenols. 2-Naphthol has several different uses including dyes, pigments, fats, oils, insecticides, pharmaceuticals, perfumes, antiseptics, synthesis of fungicides, and antioxidants for rubber. Detection of 2-Naphthol in urine usually results from long-term persistent exposure to pesticides such as chlorpyrifos, but also due to exposure to naphthalene in older types of mothballs, fires that produce polyaromatic hydrocarbons (PAHs), and tobacco smoke.; 2-Naphthol, or ?-naphthol, is a colorless crystalline solid with the formula C10H7OH. It is an isomer of 1-naphthol, differing by the location of the hydroxyl group on naphthalene. The naphthols are naphthalene homologues of phenol, with the hydroxyl group being more reactive than in the phenols. Both isomers are soluble in simple alcohols, ethers, and chloroform. They can be used in the production of dyes and in organic synthesis. For example, 2-naphthol reacts to form BINOL.