Phthalic anhydride

Phthalic anhydride
Names
	Preferred IUPAC name 2-Benzofuran-1,3-dione
	Other names Isobenzofuran-1,3-dione; Phthalic anhydride
Identifiers
CAS Number	85-44-9 ;
3D model (JSmol)	Interactive image;
Beilstein Reference	118515
ChEBI	CHEBI:36605 ;
ChEMBL	ChEMBL1371297 ;
ChemSpider	6552 ;
ECHA InfoCard	100.001.461
EC Number	201-607-5;
Gmelin Reference	27200
PubChem CID	6811;
RTECS number	TI3150000;
UNII	UVL263I5BJ ;
UN number	2214
CompTox Dashboard (EPA)	DTXSID2021159 ;
	InChI InChI=1S/C8H4O3/c9-7-5-3-1-2-4-6(5)8(10)11-7/h1-4H Key: LGRFSURHDFAFJT-UHFFFAOYSA-N ;
	SMILES O=C1OC(=O)c2ccccc12;
Properties
Chemical formula	C8H4O3
Molar mass	148.1 g/mol
Appearance	white flakes
Odor	characteristic, acrid
Density	1.53 g/cm3, solid; 1.20 g/mL, molten
Melting point	131.6 °C (268.9 °F; 404.8 K)
Boiling point	295 °C (563 °F; 568 K) sublimates
Solubility in water	0.62 g/100g (20—25 °C); ; 19.0 g/100g (100 °C); ; reacts slowly
Vapor pressure	0.0015 mmHg (20 °C)
Magnetic susceptibility (χ)	−67.31×10−6 cm3/mol
Hazards
	GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H302, H315, H317, H318, H334, H335
Precautionary statements	P261, P264, P270, P271, P272, P280, P285, P301+P312, P302+P352, P304+P340, P304+P341, P305+P351+P338, P310, P312, P321, P330, P332+P313, P333+P313, P342+P311, P362, P363, P403+P233, P405, P501
NFPA 704 (fire diamond)	3 1 0
Flash point	152 °C (306 °F; 425 K)
Explosive limits	1.7%–10.5%
	Lethal dose or concentration (LD, LC):
LD50 (median dose)	4020 mg/kg (oral, rat); 1520 mg/kg (oral, mouse); 800 mg/kg (oral, cat); 800–1600 mg/kg (oral, rat); 2210 mg/kg (oral, mouse)
	NIOSH (US health exposure limits):
PEL (Permissible)	TWA 12 mg/m3 (2 ppm)
REL (Recommended)	TWA 6 mg/m3 (1 ppm)
IDLH (Immediate danger)	60 mg/m3
Related compounds
Related compounds	Phthalic acid; Phthalimide; Phthalide
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Phthalic anhydride is the organic compound with the formula C₆H₄(CO)₂O. It is the anhydride of phthalic acid. Phthalic anhydride is a principal commercial form of phthalic acid. It was the first anhydride of a dicarboxylic acid to be used commercially. This white solid is an important industrial chemical, especially for the large-scale production of plasticizers for plastics. In 2000, the worldwide production volume was estimated to be about 3 million tonnes per year.