Phthalic anhydride appears as a white lustrous solid in the form of needles with a mild distinctive odor. Moderately toxic by inhalation or ingestion and a skin irritant. It 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.

Technical Properties

Synonyms: 1,3 Isobenzofurandione; 1,3 Dixophthalan; 1,2 Benzenedicarboxylic acid anhydride; Phthalic acid anhydride; 1,3-Isobenzofurandione
Cas Number: 85-44-9
Appearance: white flake
Odor: acrid odor
Molecular Weight: 148.11 g/mol
PH: 1.37 – 1.94 at 95 °C
Boiling Point: 284 °C
Flash Point: 151 °C Closed Cup
Vapor Pressure: 0.001 mmHg @ 30 °C
Melting Point: 131 °C
Autoignition Temperature: 570 °C
Viscosity: 6.4 mPa.s 197 °C
Bulk Density: 1.53 lb/gal