Phthalic acid
Also known as: 1,2-benzenedicarboxylic acid, o-phthalic acid, benzene-1,2-dicarboxylic acid, o-dicarboxybenzene, ortho-phthalic acid, 1,2-dicarboxybenzene
Phthalic acid (CAS 88-99-3) is a compound in the Organic Acids category listed in the Jingsj chemical database. It has the molecular formula C8H6O4 and a molecular weight of 166.131 g/mol. Key properties include a melting point of 210-211 °C (dec.)(lit.), a boiling point of 378.3±25.0 °C at 760 mmHg, a density of 1.5±0.1 g/cm3 and a flash point of 196.7±19.7 °C. It is classified under GHS with signal word Warning and hazard statements H315 — Causes skin irritation, H319 — Causes serious eye irritation and H335 — May cause respiratory irritation. No supplier offers are currently listed; request a quote. Record last updated Aug 21, 2026.
- CAS No.
- 88-99-3
- Jingsj CID
- J-38270-0
- Molecular Formula
- C8H6O4
- Molecular Weight
- 166.131 g/mol
- Category
- Organic Acids
- Last updated
- 8/21/2026
No offers for this compound yet.
Request a quotePhysicochemical Properties
| Melting Point | 210-211 °C (dec.)(lit.) |
|---|---|
| Boiling Point | 378.3±25.0 °C at 760 mmHg |
| Density | 1.5±0.1 g/cm3 |
| Flash Point | 196.7±19.7 °C |
| Exact Mass | 166.026611 |
| PSA | 74.60000 |
| LogP | 0.81 |
| Vapor Pressure | 0.0±0.9 mmHg at 25°C |
| Refractive Index | 1.618 |
| Additional Property | 7 g/L (25 ºC) |
GHS Safety & Compliance
- H315 — Causes skin irritation
- H319 — Causes serious eye irritation
- H335 — May cause respiratory irritation
Activity & Biological Data
| Target | IC50: metabolite of PAEs[1] |
|---|---|
| Additional Information | [1]. Du Yeon Bang, et al.Toxicological Characterization of Phthalic Acid. Toxicol Res 2011;27:191−203 |
Customs & Trade Information
| HS Code | 2916399090 |
|---|---|
| Summary | 2916399090 other aromatic monocarboxylic acids, their anhydrides, halides, peroxides, peroxyacids and their derivatives VAT:17.0% Tax rebate rate:9.0% Supervision conditions:none MFN tariff:6.5% General tariff:30.0% |
Frequently Asked Questions
What is the CAS number of Phthalic acid?
The CAS number of Phthalic acid is 88-99-3.
What are the molecular formula and molecular weight of Phthalic acid?
Phthalic acid has molecular formula C8H6O4 and molecular weight 166.131 g/mol.
Is Phthalic acid hazardous?
Phthalic acid has GHS signal word Warning and hazard statements H315 — Causes skin irritation; H319 — Causes serious eye irritation; H335 — May cause respiratory irritation.
What are the upstream and downstream products of Phthalic acid?
For Phthalic acid, Upstream Products: o-xylene, o-Phthalaldehyde, 2-Bromobenzonitrile; Downstream Products: 4-(1,3-dioxo-1,3-dihydro-2H-isoindol-2-yl)butanoic acid, 6-Aminophthalide, N-(4-Carboxyphenyl)phthalimide.
Data compiled from public chemical databases such as PubChem and supplier catalogs; supplier offers are provided by suppliers.
Last updated:
How to cite: Jingsj. "Phthalic acid (CAS 88-99-3)". Jingsj Chemical Database. https://www.jingsj.com/compound/J-38270-0 (accessed 2026-11-06).
Data for reference only; verify product details with suppliers before purchase.