Phthalic acid is a colorless, crystalline organic compound with the chemical formula C8H6O4. It is primarily used in the production of phthalate esters, which are commonly employed as plasticizers to enhance the flexibility and durability of plastics. Phthalic acid can also be found in dyes, pigments, and certain types of resins. This compound is produced through the oxidation of naphthalene or o-xylene. While it is generally considered safe in small amounts, concerns have been raised about the potential health effects of its derivatives, particularly in relation to endocrine disruption and environmental impact.