Functional Roles
Industries Served
Physical Properties
physical_description
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 u00b0F Flash point 305 u00b0F. Forms a corrosive solution when mixed with water. Used in the manufacture of materials such as artificial resins.
color/form
White solid (flake) or a clear colorless liquid (molten)
odor
Characteristic, acrid odor
boiling_point
563 u00b0F at 760 mmHg (sublimes) (NTP, 1992)
melting_point
267.4 u00b0F (NTP, 1992)
flash_point
329 u00b0F (Open cup); 305 u00b0F (Closed cup)
solubility
For more Solubility (Complete) data for PHTHALIC ANHYDRIDE (7 total), please visit the HSDB record page.
density
1.2 at 275 u00b0F 1.53 at 20 u00b0C (solid) (USCG, 1999) - Denser than water; will sink
vapor_density
5.1 (NTP, 1992) - Heavier than air; will sink (Relative to Air)
vapor_pressure
0.0002 mmHg at 68 u00b0F ; 0.001 mmHg at 86 u00b0F (NTP, 1992)
logp
log Kow = 1.60
autoignition_temperature
1058 u00b0F (USCG, 1999)
decomposition
Phthalic anhydride hydrolyzes rapidly in the presence of water forming phthalic acid. Half-life for phthalic anhydride was 30.5 seconds at pH 7.24. At pH 6.8 the half-life of phthtalic anhydride in water was prolonged to 61 seconds.
viscosity
1.19 mPa.s at 132 u00b0C; 1.125 mPa.s at 155 u00b0C
heat_of_combustion
-3259 kJ/mol at 25 u00b0C [
heat_of_vaporization
65.3 kJ/mol at 131 u00b0Cl
surface_tension
35.5 dynes/cm = 0.0355 N/m at 155 u00b0C
ionization_potential
10.00 eV
odor_threshold
Air: 0.053 ul/l; odor safety class C; C= Less than 50% of distracted persons perceive warning of TLV.
kovats_retention_index
1313
other_experimental_properties
Ratio of specific heats of vapor (gas): 1.080; heat of solution: -127 Btu/lb = -70.8 cal/g = -2.96x10+5 J/kg
GHS / SDS Safety
Danger
Irritant
Health Hazard
Corrosive
- H315: Causes skin irritation [Warning Skin corrosion/irritation]
- H335: May cause respiratory irritation [Warning Specific target organ toxicity, single exposure; Respiratory tract irritation]
- H334: May cause allergy or asthma symptoms or breathing difficulties if inhaled [Danger Sensitization, respiratory]
- H336: May cause drowsiness or dizziness [Warning Specific target organ toxicity, single exposure; Narcotic effects]
- H361: Suspected of damaging fertility or the unborn child [Warning Reproductive toxicity]
- H315 (99.6%): Causes skin irritation [Warning Skin corrosion/irritation]
- H402: Harmful to aquatic life [Hazardous to the aquatic environment, acute hazard]
- H317: May cause an allergic skin reaction [Warning Sensitization, Skin]
- H302: Harmful if swallowed [Warning Acute toxicity, oral]
- H318: Causes serious eye damage [Danger Serious eye damage/eye irritation]
- H317 (99.6%): May cause an allergic skin reaction [Warning Sensitization, Skin]
- H334 (99.6%): May cause allergy or asthma symptoms or breathing difficulties if inhaled [Danger Sensitization, respiratory]
- H372: Causes damage to organs through prolonged or repeated exposure [Danger Specific target organ toxicity, repeated exposure]
- H371: May cause damage to organs [Warning Specific target organ toxicity, single exposure]
- H319: Causes serious eye irritation [Warning Serious eye damage/eye irritation]
- H302 (99.6%): Harmful if swallowed [Warning Acute toxicity, oral]
- H335 (99.3%): May cause respiratory irritation [Warning Specific target organ toxicity, single exposure; Respiratory tract irritation]
- H318 (99.6%): Causes serious eye damage [Danger Serious eye damage/eye irritation]
Chemical Identity
| CAS Number | 85-44-9 |
| IUPAC Name | 2-benzofuran-1,3-dione |
| InChI Key | LGRFSURHDFAFJT-UHFFFAOYSA-N |
| PubChem CID | 6811 |
| INCI Name | PHTHALIC ANHYDRIDE |
Synonyms & Trade Names
Full Description
Phthalic anhydride (PA) is a white crystalline solid organic compound (C8H4O3) that functions as a crosslinking and curing agent in industrial applications. This specialty additive is primarily utilized in the coatings & construction and plastics & polymers industries for chemical crosslinking processes. With a melting point of 267.4°F and molecular weight of 148.11, phthalic anhydride serves as an essential reactive intermediate for polymer modification and curing systems.