Diethyl phthalate

• BPDiethyl Phthalate
• Ph. Eur.Diethyl Phthalate
• USP–NFDiethyl Phthalate

DEP; diethyl benzene-1,2-dicarboxylate; ethyl phthalate; phthalic acid diethyl ester

Diethyl benzene-1,2-dicarboxylate · [84-66-2]

UNII UF064M00AF · PubChem CID 6781

C12H14O4 · 222.24

Plasticiser

Typical concentrations: — · Dosage forms: Solid

Used as a plasticiser in film coatings, for example with cellulose acetate phthalate, hypromellose phthalate, polyvinyl acetate phthalate and ethylcellulose, typically at about 10–30% of the polymer weight. It is also used as a solvent, as a denaturant for ethanol and as a fixative in perfumes.

A clear, colourless, practically odourless, oily liquid with a slightly bitter taste.

Boiling point

about 295 °C

Relative density

about 1.117–1.121

Refractive index

about 1.500–1.505

Solubility

practically insoluble in water; miscible with ethanol, ether and most organic solvents

Stable. Store in an airtight container in a cool, dry place.

Incompatible with strong oxidising agents and strong acids. It softens or dissolves some plastics, such as polystyrene.

Made by esterifying phthalic anhydride with ethanol in the presence of an acid catalyst, followed by purification.

Of low acute toxicity; it may irritate the eyes and mucous membranes. Unlike dibutyl phthalate it is not classified as a reproductive toxicant in the EU, and the EMA has set a considerably higher permitted daily exposure for it, although exposure from medicines should still be kept low.

Observe normal precautions for the quantity handled. Eye protection and gloves are recommended; use in a well-ventilated area.

Included in the FDA Inactive Ingredient Database (oral capsules and tablets, including delayed-release forms; topical preparations) and in non-parenteral medicines licensed in Europe. EMA guidance on phthalates (2014) applies.

Dibutyl phthalate; dimethyl phthalate; dibutyl sebacate; triacetin; triethyl citrate.

Diethyl phthalate is a comparatively efficient plasticiser for phthalate-ester enteric polymers, but many companies now prefer citrate esters or triacetin to avoid phthalates altogether.