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Diethyl phthalate

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Diethyl phthalate Basic information

Product Name:
Diethyl phthalate
  • 1,2-benzenedioicacid,diethylester
  • 1,2-diethyl phthalate
  • Anozol
  • -Benzenedicarboxylic acid diethyl ester
  • Diethyl ester
  • Diethyl ester of 1,2-Benzenedicarboxylic acid
  • Diethyl-1,2-benzenedicarboxylate
  • diethyl1,2-benzenedicarboxylate
Product Categories:
  • solvent
  • Phthalates
  • Organics
  • Analytical Chemistry
  • Environmental Endocrine Disruptors
  • Functional Materials
  • Phthalates (Environmental Endocrine Disruptors)
  • Phthalates (Plasticizer)
  • Plasticizer
  • Aromatics
  • Metabolites & Impurities
  • Building Blocks
  • C12 to C63
  • Fine chemical
  • Carbonyl Compounds
  • Chemical Synthesis
  • Esters
  • Organic Building Blocks
  • bc0001
  • 84-66-2
Mol File:

Diethyl phthalate Chemical Properties

Melting point:
-3 °C (lit.)
Boiling point:
298-299 °C (lit.)
1.12 g/mL at 25 °C (lit.)
vapor density 
7.66 (vs air)
vapor pressure 
1 mm Hg ( 100 °C)
refractive index 
n20/D 1.502(lit.)
Flash point:
>230 °F
storage temp. 
Practically insoluble in water, miscible with ethanol (96 per cent).
Specific Gravity
APHA: ≤15
water-wh. oily liq., odorless, bitter taste
explosive limit
0.75%, 187°F
Water Solubility 
1 g/L (20 ºC)
Henry's Law Constant
At 25 °C: 5.01, 4.54, 4.78, 4.94, 2.21, and 2.44 (x 10-5 atm?m3/mol)at pH values of 2.96, 2.98, 6.18, 6.19, 8.98, and 9.00, respectively (Hakuta et al., 1977).
Exposure limits
TLV-TWA air 5 mg/m3 (ACGIH). .
Stable. Combustible. Incompatible with strong oxidizing agents, strong acids, alkalies.
2.2 at 41℃
CAS DataBase Reference
84-66-2(CAS DataBase Reference)
NIST Chemistry Reference
Diethyl phthalate(84-66-2)
EPA Substance Registry System
Diethyl phthalate (84-66-2)

Safety Information

Safety Statements 
UN 3082 9 / PGIII
WGK Germany 
Autoignition Temperature
854 °F
HS Code 
Hazardous Substances Data
84-66-2(Hazardous Substances Data)
LD50 i.p. in rats: 5.06 ml/kg (Singh)



Diethyl phthalate Usage And Synthesis


Diethyl phthalate (DEP) is a member of the group of esters of phthalic acid known as phthalates, used ubiquitously as solvents and plasticisers worldwide. DEP can increases the flexibility of plastics. It is also contained in deodorant formulations, perfumes, emollients and insect repellents. It can cross react with dimethyl phtalate.

Chemical Properties

Diethyl phthalate is a clear, colorless, oily liquid. It is practically odorless, or with a very slight aromatic odor and a bitter, disagreeable taste. It is miscible with ethanol and ethyl ether. Diethyl phthalate is soluble in acetone, benzene, carbon tetrachloride, alcohols, ketones, esters, and aromatic hydrocarbons and partly miscible with aliphatic solvents. Diethyl phthalate, when exposed to heat, decomposes and emits acrid smoke and irritating fumes. It is incompatible with strong oxidisers, strong acids, nitric acid, permanganates, and water and attacks some forms of plastics. Diethyl phthalate is produced in the reaction of phthalic anhydride with ethanol in the presence of concentrated sulphuric acid catalyst.

Physical properties

Clear, colorless, oily liquid with a mild, chemical odor. Bitter taste.


Diethyl phthalate is a Plasticizer for cellulose ester plastic films and sheets; in molded plastics; manufacturing varnishes; cosmetics.


Diethyl phthalate has been used as a substitute for camphor in the manufacture of celluloid, as a solvent for cellulose acetate in the manufacture of varnishes and dopes, as a ftxative for perfumes, and for denaturing ethanol.


Diethyl phthalate is an intermediate of the rodenticides dimouse, murine, and chlorpyrone, and is also an important solvent. Diethyl phthalate is used as a plasticizer for plastics. Diethyl phthalate is used as an analytical reagent, a gas chromatography stationary solution, a solvent for cellulose and esters, a plasticizer and a lubricant. Diethyl phthalate is used as plasticizer, solvent, lubricant, fixative, foaming agent for colored or rare metal mine flotation, gas chromatography fixative, alcohol denaturant, spray insecticide. This product is mixed with cellulose acetate, cellulose acetate butyrate, polyvinyl acetate, nitrocellulose, ethyl cellulose, polymethyl methacrylate, polystyrene, polyvinyl butyral, vinyl chloride-vinyl acetate Most resins such as copolymers have good compatibility. It is mainly used as a plasticizer for cellulose resin, but the product has high volatility, which limits its wide application.


ChEBI: The diethyl ester of benzene-1,2-dicarboxylic acid.

Production Methods

Diethyl phthalate is produced by the reaction of phthalic anhydride with ethanol in the presence of sulfuric acid.

Synthesis Reference(s)

Tetrahedron Letters, 34, p. 2629, 1993 DOI: 10.1016/S0040-4039(00)77642-8

General Description

A clear, colorless liquid without significant odor. More dense than water and insoluble in water. Hence sinks in water. Primary hazard is to the environment. Spread to the environment should be immediately stopped. Easily penetrates soil, contaminates groundwater and nearby waterways. Flash point 325°F. Severely irritates eyes and mildly irritates skin. Used in the manufacture of perfumes, plastics, mosquito repellents and many other products.

Air & Water Reactions

Insoluble in water.

Reactivity Profile

Diethyl phthalate is an ester. Esters react with acids to liberate heat along with alcohols and acids. Strong oxidizing acids may cause a vigorous reaction that is sufficiently exothermic to ignite the reaction products. Heat is also generated by the interaction of esters with caustic solutions. Flammable hydrogen is generated by mixing esters with alkali metals and hydrides. Can generate electrostatic charges. [Handling Chemicals Safely 1980. p. 250].

Health Hazard

Diethyl phthalate exhibited low to very lowacute toxicity in laboratory animals. Inges tion produced somnolence and hypotension.Inhalation of its vapors may result in lacrima tion, coughing, and irritation of the throatin humans. The oral LD50 value in mice is6170 mg/kg. Diethyl phthalate administeredto pregnant rats at 5% concentration in thefeed showed no adverse effect upon embryoor fetal growth, viability, or the incidence ofmalformations (Price et al. 1988).

Fire Hazard

Special Hazards of Combustion Products: Irritating vapors of unburned chemical may form in fire.

Flammability and Explosibility


Pharmaceutical Applications

Diethyl phthalate is used as a plasticizer for film coatings on tablets, beads, and granules at concentrations of 10–30% by weight of polymer.
Diethyl phthalate is also used as an alcohol denaturant and as a solvent for cellulose acetate in the manufacture of varnishes and dopes. In perfumery, diethyl phthalate is used as a perfume fixative at a concentration of 0.1–0.5% of the weight of the perfume used.

Contact allergens

This plasticizer increases the fexibility of plastics. It is also contained in deodorant formulations, perfumes, emollients, and insect repellents. It can cross-react with dimethyl phthalate.

Safety Profile

Poison by intravenous route. Moderately toxic by ingestion, subcutaneous, and intraperitoneal routes. Human systemic effects by inhalation: lachrymation, respiratory obstruction, and other unspecified respiratory system effects. An eye irritant and systemic irritant by inhalation. An experimental teratogen. Other experimental reproductive effects. Narcotic in hgh concentrations. Combustible when exposed to heat or flame. To fight fire, use water spray, mist, foam. When heated to decomposition it emits acrid smoke and irritating fumes.


Diethyl phthalate is used in oral pharmaceutical formulations and is generally regarded as a nontoxic and nonirritant material at the levels employed as an excipient. However, if consumed in large quantities it can act as a narcotic and cause paralysis of the central nervous system.
Although some animal studies have suggested that high concentrations of diethyl phthalate may be teratogenic, other studies have shown no adverse effects.
LD50 (guinea pig, oral): 8.6g/kg
LD50 (mouse, IP): 2.7g/kg
LD50 (mouse, oral): 6.2g/kg
LD50 (rat, IP): 5.1g/kg
LD50 (rat, oral): 8.6g/kg


Leaching from PVC piping in contact with water (quoted, Verschueren, 1983).

Environmental Fate

Biological. A proposed microbial degradation mechanism is as follows: 4-hydroxy-3- methylbenzyl alcohol to 4-hydroxy-3-methylbenzaldehyde to 3-methyl-4-hydroxybenzoic acid to 4-hydroxyisophthalic acid to protocatechuic acid to β-ketoadipic acid (Chapman, 1972). In anaerobic sludge, diethyl phthalate degraded as follows: monoethyl phthalate to phthalic acid to protocatechuic acid followed by ring cleavage and mineralization (Shelton et al., 1984).
Photolytic. An aqueous solution containing titanium dioxide and subjected to UV radiation (λ >290 nm) produced hydroxyphthalates and dihydroxyphthalates as intermediates (Hustert and Moza, 1988).
Chemical/Physical. Under alkaline conditions, diethyl phthalate will initially hydrolyze to ethyl hydrogen phthalate and ethanol. The monoester will undergo hydrolysis forming o-phthalic acid and ethanol (Kollig, 1993). A second-order rate constant of 2.5 x 10-2/M?sec was reported for the hydrolysis of diethyl phthalate at 30 °C and pH 8 (Wolfe et al., 1980). At 30 °C, hydrolysis halflives of 8.8 and 18 yr were reported at pH values 9 and 10-12, respectively (Callahan et al., 1979).


Diethyl phthalate is stable when stored in a well-closed container in a cool, dry place.

Purification Methods

Wash the ester with aqueous Na2CO3, then distilled water, dry (CaCl2), and distil it under reduced pressure. Store it in a vacuum desiccator over P2O5. [Beilstein 9 IV 3172.]


Incompatible with strong oxidizing materials, acids, and permanganates.

Regulatory Status

Included in the FDA Inactive Ingredients Database (oral capsules, delayed action, enteric coated, and sustained action tablets). Included in nonparenteral medicines licensed in the UK. Included in the Canadian List of Acceptable Non-medicinal Ingredients.

Diethyl phthalate Supplier

Weifang Dimeng Chemical Co., Ltd. Gold
0536-7885258 15069659527
Changzhou Xiaqing Technological Co., Ltd. Gold
519-88783621 19831955281
Guangzhou Yunmen Biotechnology Co., Ltd Gold
18902340307 18902340307
Guangzhou Nalong Chemical Co.Ltd Gold
Shanghai Jieshikai Biotechnology Co. , Ltd. Gold