Dimethyl phthalate

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Structural formula
Structure of dimethyl phthalate
Surname Dimethyl phthalate
other names
  • Dimethyl phthalate
  • Benzene-1,2-dicarboxylic acid dimethyl ester
Molecular formula C 10 H 10 O 4
Brief description

light-sensitive, colorless, almost odorless liquid

External identifiers / databases
CAS number 131-11-3
EC number 205-011-6
ECHA InfoCard 100.004.557
PubChem 8554
ChemSpider 13837329
Wikidata Q423551
Drug information
ATC code

P03 BX02

Molar mass 194.19 g mol −1
Physical state



1.19 g cm −3

Melting point

6 ° C

boiling point

282 ° C

Vapor pressure
  • 0.008 hPa (20 ° C)
  • 1.33 hPa (100 ° C)

slightly soluble in water (4.3 g l −1 )

Refractive index

1.5138 (20 ° C)

safety instructions
Please note the exemption from the labeling requirement for drugs, medical devices, cosmetics, food and animal feed
GHS labeling of hazardous substances
no GHS pictograms
H and P phrases H: no H-phrases
P: no P-phrases

Switzerland: 5 mg m −3 (measured as inhalable dust )

Toxicological data
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . Refractive index: Na-D line , 20 ° C

Dimethyl phthalate (DMP) is a phthalic acid ester made from methanol and phthalic acid and belongs to the group of phthalates in addition to diethylhexyl phthalate , di-isononyl phthalate , diethyl phthalate and dibutyl phthalate .

Presentation and extraction

The industrial production of dimethyl phthalate takes place in a two-stage synthesis from phthalic anhydride and methanol . The first step is rapid alcoholysis to form the phthalic acid half-ester. The second esterification step is slower as an equilibrium reaction and requires the use of acidic catalysts and, in order to complete the conversion, the distillative separation of the water formed.

Dimethyl phthalate synthesis01.svg


Dimethyl phthalate is a light-sensitive, colorless, less volatile, highly viscous (dynamic viscosity of 1.7 mPa · s at 20 ° C.) And almost odorless liquid that is sparingly soluble in water. It decomposes in the heat, producing carbon monoxide and carbon dioxide as well as irritating vapors and gases.

Dimethyl phthalate is considered a difficultly flammable liquid. Flammable vapor-air mixtures can form above the flash point . The compound has a flash point of 146 ° C. The explosion range begins at 0.9 vol.% As the lower explosion limit (LEL). The lower explosion point is 134 ° C. The ignition temperature is 555 ° C. The substance therefore falls into temperature class T1.


DMP is used as a plasticizer , as a repellent against insects, where it is particularly effective against Anopheles , and as a solvent in glow sticks ("glow stick").

Individual evidence

  1. Entry on DIMETHYL PHTHALATE in the CosIng database of the EU Commission, accessed on February 11, 2020.
  2. a b c d e f g h i j k l m n o p Entry for CAS no. 131-11-3 in the GESTIS substance database of the IFA , accessed on June 28, 2018(JavaScript required) .
  3. David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Physical Constants of Organic Compounds, pp. 3-208.
  4. Swiss Accident Insurance Fund (Suva): Limit values ​​- current MAK and BAT values (search for 131-11-3 or dimethyl phthalate ), accessed on November 2, 2015.
  5. a b P.M. Lorz, FK Towae, W. Enke, R. Jäckh, N. Bhargava, W. Hillesheim: Phthalic Acid and Derivatives in Ullmann's Encyclopedia of Industrial Chemistry, 2007 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim, doi : 10.1002 / 14356007 .a20_181.pub2 .
  6. a b E. Brandes, W. Möller: Safety-related parameters. Volume 1: Flammable Liquids and Gases. Wirtschaftsverlag NW - Verlag für neue Wissenschaft, Bremerhaven 2003.
  7. Wolfgang Legrum: Fragrances, between stink and fragrance , Vieweg + Teubner Verlag (2011) p. 75, ISBN 978-3-8348-1245-2 .
  8. Military Preventive Medicine: Mobilization and Deployment, Vol 1.Chapter 22: Personal Protection Measures Against Arthropods, p. 508.