Phthalic anhydride appears as a colorless to white lustrous solid in the form of needles with a mild distinctive odor. Moderately toxic by inhalation or ingestion and a skin irritant. Melting point 64°F Flash point 305°F. Forms a corrosive solution when mixed with water. Used in the manufacture of materials such as artificial resins. Phthalic anhydride is the cyclic dicarboxylic anhydride that is the anhydride of phthalic acid. It has a role as an allergen. It is a cyclic dicarboxylic anhydride and a member of 2-benzofurans.

Plasticizer production:Preparation of mainstream plasticizers such as dibutyl phthalate (DBP) and dioctyl phthalate (DOP), used in PVC plastic processing.

Resin synthesis:Production of unsaturated polyester resins and alkyd resins, applied in coatings, fiberglass reinforced plastics (FRP), and adhesives.

Dyes and pharmaceuticals:Synthesis of anthraquinone dyes, fluorescent brighteners, and some pharmaceutical intermediates.

Others:Used as chemical analysis reagents, pesticide intermediates, raw materials for rubber antioxidants, etc.