Phthalic acid CAS 88-99-3

Phthalic acid is an organic compound with the chemical formula C₈H₆O₄, a molecular weight of 166.13, and appears as white crystals or crystalline powder. ‌

The melting point is 210-211°C (decomposition), the boiling point is 230°C (decomposition), the density is 1.59g /cm³ (at 15°C), and the flash point is 168°C. It is soluble in methanol and ethanol, slightly soluble in water and ether, and insoluble in solvents such as chloroform and benzene. ‌

It is mainly used in the production of polyester resins, polyester, drugs and plasticizers, and also serves as a raw material for synthetic resins and synthetic fibers. It can also be used as an analytical reagent and standard substance. ‌

In industry, it is mostly produced from o-methylformic acid, o-xylene or naphthalene as raw materials through oxidation or hydrolysis, and can also be directly used to produce phthalic anhydride

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Model:
88-99-3
Brand:
futurechemical
Code:
88-99-3

Product Description

Phthalic acid Basic information
Product Name:	Phthalic acid
CAS:	88-99-3
MF:	C8H6O4
MW:	166.13
EINECS:	201-873-2
Mol File:	88-99-3.mol
Phthalic acid Chemical Properties
Melting point	210-211 °C (dec.) (lit.)
Boiling point	214.32°C (rough estimate)
bulk density	960kg/m3
density	1.59 g/cm3 at 15 °C
vapor pressure	7.8 hPa (191 °C)
refractive index	1.5100 (estimate)
Fp	168 °C
storage temp.	Store below +30°C.
solubility	methanol: 0.1 g/mL, clear
pka	2.89(at 25℃)
form	Powder
color	White
PH	3.2(1 mM solution);2.55(10 mM solution);2(100 mM solution);
Water Solubility	7 g/L (25 ºC)
Merck	147,371
BRN	608199
Dielectric constant	5.1（Ambient）
Stability:	Stable. Combustible. Incompatible with strong oxidizing agents.
InChIKey	XNGIFLGASWRNHJ-UHFFFAOYSA-N
LogP	0.73 at 20℃
CAS DataBase Reference	88-99-3(CAS DataBase Reference)
NIST Chemistry Reference	1,2-Benzenedicarboxylic acid(88-99-3)
EPA Substance Registry System	Phthalic acid (88-99-3)

Phthalic acid 88-99-3 C8H6O4 Plasticizer Solvent for personal care products PVC plastic softening modifier

Quality Assurance

Full-Process Quality Control: From incoming raw material inspection to in-process monitoring and final outgoing checks, every batch is inspected at each production stage against strict acceptance standards.
Third-Party Certified & Tested: Our quality management system is certified to ISO 9001, and products are regularly tested by accredited laboratories (e.g. SGS, TÜV). Test reports are available on request.
100% Batch Traceability: Each batch carries a unique lot number that links raw material records, production parameters, and test results, enabling complete traceability from factory to final delivery.
Pre-Shipment Inspection: Every order passes a final pre-shipment inspection, with inspection photos and reports shared before dispatch.

FAQ From Customers

Q1: What is the minimum order quantity?

A: There is no quantity limit for the first sample or trial order. Just tell us the actual quantity you need.
Q2: How can I confirm that the quality meets the requirements?

A: Provide your specifications, and our technical team will check them or customize them for you; we can provide TDS, MSDS, and COA, and accept third-party testing.
Q3: How do you ensure stable quality?

A: We manufacture under an ISO 9001 quality system, test every batch before release, and retain samples for 24 months for traceability.
Q4: Do you provide samples?

A: Yes — Free samples are available; freight is at buyer's expense for express delivery.