CompoundList
Sign in
Cosmetic ingredients

Phthalic anhydride

Also known as 1,3-Isobenzofurandione, 2-Benzofuran-1,3-dione, Phthalandione

CAS 85-44-9Formula C8H4O3Molar mass 148.12 g/molEC 201-607-5
GHS signal word: Danger. Pictograms: Corrosive, Harmful or irritant, Serious health hazard 255 suppliers listed
Get quotes Compare 255 suppliers
Phthalic anhydride chemical structure, C8H4O3, CAS 85-44-9
2D chemical structure

Key facts

What buyers check first

All properties
Appearance
White, lustrous needles
Melting point
131.4 °C
Boiling point
285.3 °C
Density
1.53 g/cm³
Flash point
152 °C
HS code
291735
Category
Cosmetic ingredients
UN number
UN 2214
Illustrative photo, colourless crystals beside a jumbo bulk bag in a chemical plant
Typical packagingIllustrative packaging image, not the actual product

What is Phthalic anhydride?

Plain description, key identifiers and synonyms

Phthalic anhydride is the cyclic dicarboxylic anhydride that is the anhydride of phthalic acid. It has a role as an allergen. It is a cyclic dicarboxylic anhydride and a member of 2-benzofurans.

Identifiers

Registry numbers, names and line notations, tap to copy

IUPAC name
2-benzofuran-1,3-dione
CAS number
85-44-9 CAS number cross-checked
EC number
201-607-5
Molecular formula
C8H4O3
UNII
UVL263I5BJ
MDL number
MFCD00005918
INCI name
PHTHALIC ANHYDRIDE
InChIKey
LGRFSURHDFAFJT-UHFFFAOYSA-N
InChI
InChI=1S/C8H4O3/c9-7-5-3-1-2-4-6(5)8(10)11-7/h1-4H
SMILES (canonical and isomeric)
C1=CC=C2C(=C1)C(=O)OC2=O

Synonyms

  • 1,3-Isobenzofurandione
  • 2-Benzofuran-1,3-dione
  • Phthalandione
  • Retarder esen
  • 1,3-Dioxophthalan
  • 1,3-Phthalandione
  • Phthalic acid anhydride
  • Retarder AK
  • Retarder PD
  • o-Phthalic acid anhydride
  • Phthalsaeureanhydrid
  • ESEN
  • Vulkalent B/C
  • Anidride ftalica
  • Ftalowy bezwodnik
  • Ftaalzuuranhydride
  • Anhydride phtalique
  • Ftalanhydrid
  • 1,2-Benzenedicarboxylic anhydride
  • 1,2-Benzenedicarboxylic acid anhydride
  • Vulkalent B
  • Wiltrol P
  • RCRA waste number U190
  • TGL 6525
  • Anhydrid kyseliny ftalove
Show all 33 synonyms
  • Isobenzofuran, 1,3-dihydro-1,3-dioxo-
  • Isobenzofuran-1,3-dione
  • 1,3-dihydro-2-benzofuran-1,3-dione
  • phtalic anhydride
  • ortho-phthalic acid anhydride
  • o-phthalic anhydride
  • Phthalanhydride
  • Sconoc 7

Physical and chemical properties

Measured values and descriptors computed from the structure

Physical and chemical properties

Measured values, check the supplier specification for your grade

Appearance
White, lustrous needlesexp.
Odour
Mildexp.
Melting point
131.4 °Cexp.
Boiling point
285.3 °Cexp.
Density
1.53 g/cm³exp.
Flash point
152 °Cexp.
Autoignition temperature
570 °Cexp.
Solubility
In water, 6,000 mg/L at 25 °Cexp.
Vapour pressure
5.17 × 10⁻⁴ mm Hg at 25 °Cexp.

Values vary by grade. Ask suppliers for the COA or TDS of the batch you buy.

Computed descriptors

Calculated from the structure, useful for screening and formulation

Molecular weight
148.12 g/molcalc.
Exact mass
148.016 Dacalc.
LogP (octanol/water)
1calc.
Topological polar surface area
43.37 Ųcalc.
Hydrogen bond donors
0calc.
Hydrogen bond acceptors
3calc.
Rotatable bonds
0calc.
Heavy atoms
11calc.
Rings
2calc.
Aromatic rings
1calc.
Fraction sp3 carbons
0calc.
Formal charge
0calc.
Stereocentres
0calc.
Lipinski rule of five
Passes (0 violations)calc.

Calculated for screening. Confirm critical figures with the supplier.

Murcko scaffold

The ring system that remains when every side chain is removed

Murcko scaffold of this chemical, O=C1OC(=O)c2ccccc21

O=C1OC(=O)c2ccccc21

2 rings, 11 atoms. This chemical is the scaffold itself.

156 other chemicals share this scaffold

Safety and hazards

GHS classification summary, not a safety data sheet

GHS signal word
Danger
GHS05: Corrosive
Corrosive
GHS07: Harmful or irritant
Harmful or irritant
GHS08: Serious health hazard
Serious health hazard
120NFPA 704 rating

Hazard statements

  • H302Harmful if swallowed.
  • H315Causes skin irritation.
  • H317May cause an allergic skin reaction.
  • H318Causes serious eye damage.
  • H334May cause allergy or asthma symptoms or breathing difficulties if inhaled.
  • H335May cause respiratory irritation.
Precautionary statements (26)
  • P233Keep container tightly closed.
  • P260Do not breathe dust, fume, gas, mist, vapours or spray.
  • P261Avoid breathing dust, fume, gas, mist, vapours or spray.
  • P264Wash skin thoroughly after handling.
  • P264 + P265Wash skin thoroughly after handling. Do not touch eyes.
  • P270Do not eat, drink or smoke when using this product.
  • P271Use only outdoors or in a well-ventilated area.
  • P272Contaminated work clothing should not be allowed out of the workplace.
  • P280Wear protective gloves, protective clothing, eye protection and face protection.
  • P284In case of inadequate ventilation wear respiratory protection.
  • P301 + P317If swallowed: Get medical help.
  • P302 + P352If on skin: Wash with plenty of water.
  • P304 + P340If inhaled: Remove person to fresh air and keep comfortable for breathing.
  • P305 + P354 + P338If in eyes: Immediately rinse with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.
  • P317Get medical help.
  • P319Get medical help if you feel unwell.
  • P321Specific treatment (see supplemental first aid instructions on the label).
  • P330Rinse mouth.
  • P332 + P317If skin irritation occurs: Get medical help.
  • P333 + P317If skin irritation or rash occurs: Get medical help.
  • P342 + P316If experiencing respiratory symptoms: Get emergency medical help immediately.
  • P362 + P364Take off contaminated clothing. And wash it before reuse.
  • P403Store in a well-ventilated place.
  • P403 + P233Store in a well-ventilated place. Keep container tightly closed.
  • P405Store locked up.
  • P501Dispose of contents and container in accordance with local regulations.
UN number
UN 2214

GHS classification summary, not a safety data sheet (SDS). Classifications can differ by supplier, grade and concentration. Always check the supplier's SDS.

Full safety data and first aid

Phthalic anhydride suppliers

Sponsored listings first, then the documented ranking: membership, verification, replies, completeness, freshness and ratings

All 255 suppliers
30 of 30 offers

Suppliers marked Unclaimed profile have not claimed their profile yet. They are not verified by CompoundList, their offers are price on request and details may have changed, so please confirm them with the supplier. Company representatives can claim a profile with a business email on the company's own website domain. Our team verifies each claim and sends the result by email.

Where suppliers are based

255 suppliers in 43 countries

Send one request to many suppliers

Choose up to 10 suppliers or let us match your request. Compare quotes side by side, free.

Choose suppliersPost a request

Phthalic anhydride price

Indicative price range per kg from live supplier offers

No published prices right now

Suppliers quote this chemical on request. Send one free request and compare quotes side by side.

Get latest price

Uses and applications

What the substance is used for, by industry and function

Manufacture phthaleins, phthalates, benzoic acid, synthetic indigo, artificial resins (glyptal). Buffer.

Chem int for dioctyl phthalates-eg, di(2-ethylhexyl), other phthalate plasticizers-eg, dibutyl, insect repellents-eg, dimethyl phthalate, unsaturated polyester resins, alkyd resins, dyes and pigments, isatoic anhydride, halogenated phthalic anhydrides, diallyl phthalate, urethane polyester polyols, phenolphthalein, curing agent for epoxy resins.

Rubber retarder.

Scorch inhibitor for rubber stocks.

Phthalic anhydride is an important chemical intermediate in the plastics industry from which are derived numerous phthalate esters that function as plasticizers in synthetic resins. Phthalic anhydride itself is used as a monomer for synthetic resins such as glyptal, the alkyd resins, and the polyester resins.

Read more

Phthalic anhydride is used in the synthesis of primary amines, the agricultural fungicide phaltan, and thalidomide. Other reactions with phthalic anhydride yield phenolphthalein, benzoic acid, phthalylsulfathiazole (an intestinal antimicrobial agent), and orthophthalic acid.

Industrial uses: Dye, Pigment, Hardener, Intermediate, Filler, Flame retardant, Plasticizer, Processing aids not otherwise specified.

Consumer uses: Hardener, Intermediate, Processing aids not otherwise specified, Binder, Solvent.

Cosmetic ingredient, INCI name PHTHALIC ANHYDRIDE(not reported)

Roles

  • aetiopathogenetic role
  • allergen

Functional uses

  • Chemical reaction regulator
  • Flame retardant
  • Plasticizer

Cosmetic functions

  • Not reported

How it is made

Prepared from naphthalene by oxidation with a mixture of HgSO4 and CuSO4 in presence of H2SO4, by passing naphthalene and oxygen over a suitable catalyst at 400-500 °C.

/Commercial production by/ ... gas-phase oxidation of naphthalene or o-xylene in an air stream with vanadium oxide as catalyst.

Regulatory status

Inventories, regulations and trade controls that list this substance

Europe

  • EU harmonised classification (CLP Annex VI)
    Index no: 607-009-00-4

Health and food

  • EU cosmetic ingredient inventory

United States

  • TSCA inventory (USA)
    Status: Active in US commerce

HS code and trade data

Customs classification and reported world trade statistics

Global trade

World import and export statistics for the HS code Phthalic anhydride is traded under.

HS 2917.35Exact HS code

Acids: aromatic polycarboxylic acids, phthalic anhydride

World exports in 2024
$614M
−8.6% vs 2023, imports $739M
2019 to 2024
Top exporters
  1. China22.0%
  2. South Korea17.1%
  3. Belgium15.5%
Top importers
  1. Turkey13.2%
  2. Netherlands7.7%
  3. Indonesia6.3%
Reported customs values in USD, not prices.Full trade data

The HS code shown for Phthalic anhydride is indicative (it was matched by name in the HS nomenclature). Confirm the classification with your customs broker before shipping.

Frequently asked questions

Quick answers about Phthalic anhydride, based on the data on this page

What is Phthalic anhydride?

Phthalic anhydride is the cyclic dicarboxylic anhydride that is the anhydride of phthalic acid. It has a role as an allergen. It is a cyclic dicarboxylic anhydride and a member of 2-benzofurans.

What is the CAS number of Phthalic anhydride?

The CAS registry number of Phthalic anhydride is 85-44-9.

What is the molecular formula and weight of Phthalic anhydride?

The molecular formula of Phthalic anhydride is C8H4O3 and its molar mass is 148.12 g/mol.

What is Phthalic anhydride used for?

Manufacture phthaleins, phthalates, benzoic acid, synthetic indigo, artificial resins (glyptal). Buffer.

Is Phthalic anhydride hazardous?

Phthalic anhydride carries the GHS signal word "Danger". Main hazards: harmful if swallowed, causes skin irritation, may cause an allergic skin reaction. This summary is not an SDS, always read the supplier safety data sheet.

What is the HS code of Phthalic anhydride?

Phthalic anhydride is usually classified under HS code 291735 (Phthalic anhydride). This is indicative, confirm it with your customs broker before shipping.

Where can I buy Phthalic anhydride?

CompoundList lists 255 suppliers of Phthalic anhydride in United States, China, India, Germany and 39 more. Send one free request to get and compare quotes. Your contact details stay private until you accept a quote.

Where can I buy Phthalic anhydride in India?

47 suppliers in India list Phthalic anhydride on CompoundList. Filter the suppliers list by country and send a request to compare prices, grades and delivery times.

What is the price of Phthalic anhydride?

Suppliers quote Phthalic anhydride on request because prices depend on grade, purity, quantity and destination. A free request on CompoundList gets you several quotes to compare.

Guides for buyers

Practical guides that help when you source, ship or handle Phthalic anhydride

Get quotes for Phthalic anhydride

Post one free request with your grade, quantity and destination. Matching suppliers send quotes you can compare side by side.
Post a request Sell Phthalic anhydride
Data last updated 7 Oct 2026. Details may have changed, please confirm them with the supplier. Report an error on this page
Embed this structure on your websiteShow code

Paste this code into your page to show the 2D structure of Phthalic anhydride with a 3D view, its CAS number where known and a link back to this page. Free to use with the link kept.

<iframe src="https://www.compoundlist.com/embed/structure/phthalic-anhydride-85-44-9" title="Phthalic anhydride structure on CompoundList" width="360" height="420" style="border:1px solid #E7E2DA;border-radius:12px;max-width:100%" loading="lazy" referrerpolicy="strict-origin-when-cross-origin"></iframe>
Preview the embed

Explore more in Cosmetic ingredients or HS code 291735

255 suppliers
Free quotes, contact stays private
Get quotes