- ▸ Phosphorus flame retardant for polyester resins and textile finishes
- ▸ Reactive intermediate and methylating agent in chemical synthesis
- ▸ Catalyst and solvent component in polymer processing
A grade-specific Safety Data Sheet (SDS) — with the complete hazard classification, handling precautions, and transport information — is supplied with every shipment and available on request. Confirm all safety and regulatory details against the SDS for your specific grade.
Request SDS →⚠ WARNING: This product can expose you to Trimethyl Phosphate, which is known to the State of California to cause cancer. For more information go to www.P65Warnings.ca.gov.
Trimethyl phosphate (TMP) is a very low-molecular-weight, halogen-free trialkyl phosphate with the highest phosphorus fraction of the common alkyl phosphates. It is used as a flame retardant, a solvent, and a methylating agent / chemical intermediate. Identity: CAS 512-56-1.
What it is
Trimethyl phosphate (CAS 512-56-1) is a clear, low-viscosity liquid. Its small molecule gives a high phosphorus content per unit weight, which is efficient where a halogen-free phosphorus FR is needed at low loading.
How it performs in fire
As a flame retardant it delivers phosphorus efficiently to the condensed and vapor phases. Separately it is a widely used solvent and a methylating agent in organic synthesis, so the same product serves FR and intermediate roles.
Applications
TMP is used as a halogen-free flame retardant in resins and foams, and as a solvent and methylating intermediate in chemical synthesis. Compare the slightly higher-MW TEP where lower volatility is wanted.
Forms, grades and handling
TMP is supplied as a clear, low-viscosity liquid in drums, IBCs and bulk. Properties are typical reference values; the Certificate of Analysis (CoA) for the lot you buy governs. Handle per the current Safety Data Sheet (SDS), and confirm regulatory status and restrictions for your market and end use — flame-retardant regulation evolves. Each lot ships with CoA, TDS and SDS.
Bulk supply and RFQ
RawSource sources Trimethyl Phosphate direct from producers in bulk, with CoA, TDS and SDS per lot. Tell us your polymer or system, the fire test you must pass, your maximum loading, and whether the application must be halogen-free, and we will quote the right grade. See the full range and selection logic in the flame retardants guide.
Typical Properties
Typical reference values, not a specification; the Certificate of Analysis (CoA) for the lot governs.
| Property | Typical Value |
|---|---|
| Chemical / class | Flame retardant / solvent / intermediate (trialkyl phosphate) |
| Flame-retardant type | Halogen-free trialkyl phosphate |
| Role in fire performance | Condensed/vapor phase; phosphorus source |
| CAS Number | 512-56-1 |
| Molecular Formula | C3H9O4P |
| Molecular Weight | 140.07 g/mol |
| Handling | Refer to the current SDS |
Regulatory & registration requirements
- TSCA (US):
- REACH (EU):
- EC number: 208-144-8
Source: EPA TSCA Inventory (July 2025 release) · ECHA CHEM — retrieved 2026-07-12
Regulatory restriction status
Trimethyl Phosphate (TMP) (CAS 512-56-1) appears on the regulatory list(s) below. This is public regulatory information about the substance — not a statement about any specific supplier’s material, and not a safety claim. Confirm the current status for your jurisdiction and intended use.
- California Proposition 65: listed for cancer, listed 1 May 1996. A California Proposition 65 warning applies (see the warning above).
Sources: ECHA Candidate List / Annex XIV / Annex XVII (echa.europa.eu); U.S. EPA TSCA; UN Stockholm Convention / EU POPs Regulation; California OEHHA Proposition 65 list. Retrieved 2026-07-13.
Frequently Asked Questions
What is trimethyl phosphate (TMP) used for?
Trimethyl phosphate (CAS 512-56-1) is a halogen-free trialkyl phosphate used as a flame retardant, a solvent, and a methylating agent / chemical intermediate. Its small molecule gives a high phosphorus content for efficient FR action.
What is the difference between TMP and TEP?
Both are halogen-free trialkyl phosphates; TMP (trimethyl) has the higher phosphorus fraction and is more volatile, while TEP (triethyl) is slightly higher in molecular weight and lower in volatility. Choose by phosphorus efficiency vs volatility.
How is bulk trimethyl phosphate supplied and quoted?
RawSource supplies trimethyl phosphate in bulk with CoA, TDS and SDS per lot. Pricing is quote-based on grade and volume; submit an RFQ with your target quantity, polymer/system and the fire test you must pass.
What is the REACH and TSCA regulatory status of Trimethyl Phosphate (TMP)?
Trimethyl Phosphate (TMP) (CAS 512-56-1) is subject to U.S. TSCA Inventory requirements; supplying it into the EU requires valid REACH registration ((EC) No 1907/2006). RawSource cannot verify a third-party supplier's registrations — buyers should require documented TSCA and REACH compliance for their jurisdiction and volume (EC 208-144-8).