Trimethyl phosphite
Also known as: Trimethoxyphosphine, Methyl phosphite, Phosphorous acid, trimethyl ester, Trimethylfosfit, Fosforyn trojmetylowy, Methyl phosphite (P(OMe)3)
Trimethyl phosphite (CAS 121-45-9) is a compound in the Organic Acids category listed in the Jingsj chemical database. It has the molecular formula C3H9O3P and a molecular weight of 124.076 g/mol. Key properties include a melting point of −78 °C(lit.), a boiling point of 110.2±8.0 °C at 760 mmHg, a density of 1.052 g/mL at 25 °C(lit.) and a flash point of 27.8±0.0 °C. It is classified under GHS with signal word Danger and hazard statements H226 — Flammable liquid and vapour, H302 — Harmful if swallowed and H315 — Causes skin irritation. No supplier offers are currently listed; request a quote. Record last updated Aug 21, 2026.
- CAS No.
- 121-45-9
- Jingsj CID
- J-20633-7
- Molecular Formula
- C3H9O3P
- Molecular Weight
- 124.076 g/mol
- Category
- Organic Acids
- Last updated
- 8/21/2026
No offers for this compound yet.
Request a quotePhysicochemical Properties
| Melting Point | −78 °C(lit.) |
|---|---|
| Boiling Point | 110.2±8.0 °C at 760 mmHg |
| Density | 1.052 g/mL at 25 °C(lit.) |
| Flash Point | 27.8±0.0 °C |
| Exact Mass | 124.028931 |
| PSA | 41.28000 |
| LogP | -0.93 |
| Additional Property | 4.3 (vs air) |
| Vapor Pressure | 28.1±0.2 mmHg at 25°C |
| Refractive Index | n20/D 1.408(lit.) |
GHS Safety & Compliance
- H226 — Flammable liquid and vapour
- H302 — Harmful if swallowed
- H315 — Causes skin irritation
- H318 — Causes serious eye damage
- H335 — May cause respiratory irritation
Customs & Trade Information
| HS Code | 2920901100 |
|---|---|
| Summary | 2920901100 trimethyl phosphite。supervision conditions:23(import license for dual-use item and technologies,export license for dual-use item and technologies)。VAT:17.0%。tax rebate rate:9.0%。MFN tarrif:6.5%。general tariff:30.0% |
Frequently Asked Questions
What is the CAS number of Trimethyl phosphite?
The CAS number of Trimethyl phosphite is 121-45-9.
What are the molecular formula and molecular weight of Trimethyl phosphite?
Trimethyl phosphite has molecular formula C3H9O3P and molecular weight 124.076 g/mol.
Is Trimethyl phosphite hazardous?
Trimethyl phosphite has GHS signal word Danger and hazard statements H226 — Flammable liquid and vapour; H302 — Harmful if swallowed; H315 — Causes skin irritation.
What are the upstream and downstream products of Trimethyl phosphite?
For Trimethyl phosphite, Upstream Products: Methanol, Sodium methoxide, Dimethyl phosphonate; Downstream Products: Dichlorvos, Trichlorfon, Methanol.
Data compiled from public chemical databases such as PubChem and supplier catalogs; supplier offers are provided by suppliers.
Last updated:
How to cite: Jingsj. "Trimethyl phosphite (CAS 121-45-9)". Jingsj Chemical Database. https://www.jingsj.com/compound/J-20633-7 (accessed 2026-11-09).
Data for reference only; verify product details with suppliers before purchase.