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Sulfur and phosphorus compounds

Triethyl phosphite

Also known as Triethoxyphosphine, Phosphorous acid, triethyl ester, Ethyl phosphite, (EtO)3P

CAS 122-52-1Formula C6H15O3PMolar mass 166.16 g/molEC 204-552-5
GHS signal word: Warning. Pictograms: Flammable, Harmful or irritant Controlled, licensed buyers only
Request as a licensed buyer Safety data
Triethyl phosphite chemical structure, C6H15O3P, CAS 122-52-1
2D chemical structure

Key facts

What buyers check first

All properties
Appearance
Colorless liquid
Melting point
-112 °C
Boiling point
157.9 °C
Density
Relative density (water = 1): 0.97
Flash point
54 °C
HS code
292024
Category
Sulfur and phosphorus compounds
UN number
UN 2323

What is Triethyl phosphite?

Plain description, key identifiers and synonyms

Triethyl phosphite appears as a clear colorless liquid with a strong foul odor. Flash point 130 °F. Less dense than water and insoluble in water. Vapors heavier than air.

Identifiers

Registry numbers, names and line notations, tap to copy

IUPAC name
triethyl phosphite
CAS number
122-52-1 CAS number cross-checked
EC number
204-552-5
Molecular formula
C6H15O3P
UNII
6B2R04S55G
MDL number
MFCD00009084
InChIKey
BDZBKCUKTQZUTL-UHFFFAOYSA-N
InChI
InChI=1S/C6H15O3P/c1-4-7-10(8-5-2)9-6-3/h4-6H2,1-3H3
SMILES (canonical and isomeric)
CCOP(OCC)OCC

Synonyms

  • Triethoxyphosphine
  • Phosphorous acid, triethyl ester
  • Ethyl phosphite, (EtO)3P
  • Fosforyn trojetylowy
  • Tris(ethoxy)phosphine
  • triethylphosphite
  • Phosphorous Acid Triethyl Ester
  • Triethoxyphosphine-d15
  • P(OEt)3
  • (C2H5O)3P
  • Phosphorus ether
  • triethyl-phosphite
  • tri ethyl phosphite
  • Triethyl phosphite, 98%
  • (EtO)3P
  • 4-01-00-01333 (Beilstein Handbook Reference)
  • P(OC2H5)3
  • UN 2323
  • Triethyl phosphite, purum, >=95.0% (GC)
  • Triethyl phosphite [UN2323] [Flammable liquid]
  • Triethyl phosphite 100 microg/mL in Acetonitrile
  • Ethyl phosphite, (EtO)3P (7CI), Ethyl phosphite, Et3PO3 (4CI), NSC 5284, Triethoxyphosphine, Tris(ethoxy)phosphine

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
Colorless liquidexp.
Odour
Pungent odorexp.
Melting point
-112 °Cexp.
Boiling point
157.9 °Cexp.
Density
Relative density (water = 1): 0.97exp.
Flash point
54 °Cexp.
Autoignition temperature
250 °Cexp.
Solubility
Solubility in water: reactionexp.
Vapour pressure
1.95 mm Hg at 20 °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
166.16 g/molcalc.
Exact mass
166.0759 Dacalc.
LogP (octanol/water)
2.32calc.
Topological polar surface area
27.69 Ųcalc.
Hydrogen bond donors
0calc.
Hydrogen bond acceptors
3calc.
Rotatable bonds
6calc.
Heavy atoms
10calc.
Rings
0calc.
Aromatic rings
0calc.
Fraction sp3 carbons
1calc.
Formal charge
0calc.
Stereocentres
0calc.
Lipinski rule of five
Passes (0 violations)calc.

Calculated for screening. Confirm critical figures with the supplier.

Safety and hazards

GHS classification summary, not a safety data sheet

GHS signal word
Warning
GHS02: Flammable
Flammable
GHS07: Harmful or irritant
Harmful or irritant

Hazard statements

  • H226Flammable liquid and vapour.
  • H302Harmful if swallowed.
  • H315Causes skin irritation.
  • H317May cause an allergic skin reaction.
  • H319Causes serious eye irritation.
  • H332Harmful if inhaled.
  • H335May cause respiratory irritation.
  • H412Harmful to aquatic life with long lasting effects.
Precautionary statements (32)
  • P210Keep away from heat, hot surfaces, sparks, open flames and other ignition sources. No smoking.
  • P233Keep container tightly closed.
  • P240Ground and bond container and receiving equipment.
  • P241Use explosion-proof electrical, ventilating and lighting equipment.
  • P242Use non-sparking tools.
  • P243Take action to prevent static discharges.
  • 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.
  • P273Avoid release to the environment.
  • P280Wear protective gloves, protective clothing, eye protection and face protection.
  • P301 + P317If swallowed: Get medical help.
  • P302 + P352If on skin: Wash with plenty of water.
  • P303 + P361 + P353If on skin (or hair): Take off immediately all contaminated clothing. Rinse skin with water or shower.
  • P304 + P340If inhaled: Remove person to fresh air and keep comfortable for breathing.
  • P305 + P351 + P338If in eyes: Rinse cautiously 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.
  • P337 + P317If eye irritation persists: Get medical help.
  • P362 + P364Take off contaminated clothing. And wash it before reuse.
  • P370 + P378In case of fire: Use appropriate media to extinguish.
  • P403 + P233Store in a well-ventilated place. Keep container tightly closed.
  • P403 + P235Store in a well-ventilated place. Keep cool.
  • P405Store locked up.
  • P501Dispose of contents and container in accordance with local regulations.
UN number
UN 2323
Transport hazard class
3
Packing group
III

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

Triethyl phosphite suppliers

Controlled substance, listings of documented suppliers only, in the documented ranking

Chemical Weapons Convention Schedule 3

Triethyl phosphite is controlled. Only documented suppliers can list it, and buyers must upload a valid licence with their request. Every request is reviewed before suppliers see it.

Licensed buyers only, every enquiry is reviewed by our compliance team.

Reference: OPCW Chemical Weapons Convention Schedule 3, HS 2022 subheading 2920.24 (triethyl phosphite)

Our policy on controlled substances
No documented supplier lists it yet

Licensed buyers can post a request for Triethyl phosphite with their licence. Our compliance team reviews it before suppliers see it.

Request as a licensed buyer

Triethyl phosphite 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.

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Uses and applications

What the substance is used for, by industry and function

Reagent in synthetic organic chemistry.

Synthesis, plasticizers, stabilizers, lubricants and grease additives.

Plasticizer, vinyl stabilizer, grease additive, color inhibitor for resins.

Schedule 3B precursor to dimethyl methylphosphonate (which is a sarin precursor and nerve agent simulant).

Triethyl phosphite is exclusively used as an intermediate for the manufacturing of different products: flame retardants (about 60 %), optical brighteners (about 15 %), pesticides (about 15 %), antioxidants (about 5 %), and pharmaceuticals (about 5 %).

Industrial uses: Intermediate.

How it is made

Triethyl phosphite is produced in a closed system by reaction of phosphorous trichloride and ethanol in the presence of an inorganic or organic base. The product is purified by distillation.

Reaction of ethyl alcohol and phosphorus trichloride in the presence of a tertiary amine.

Regulatory status

Inventories, regulations and trade controls that list this substance

Chemical Weapons Convention Schedule 3

Triethyl phosphite is controlled. Only documented suppliers can list it, and buyers must upload a valid licence with their request. Every request is reviewed before suppliers see it.

Licensed buyers only, every enquiry is reviewed by our compliance team.

Reference: OPCW Chemical Weapons Convention Schedule 3, HS 2022 subheading 2920.24 (triethyl phosphite)

Our policy on controlled substances

Controls

  • Chemical Weapons Convention Schedule 3

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 Triethyl phosphite is traded under.

HS 2920.24Exact HS code

Esters: phosphite esters and their salts, their halogenated, sulphonated, nitrated or nitrosated derivatives…

World exports in 2024
$2.47M
−9.4% vs 2023, imports $1.74M
2019 to 2024
Top exporters
  1. China65.7%
  2. India * partner reported30.3%
  3. Germany1.4%
Top importers
  1. United States24.1%
  2. Italy16.2%
  3. France * partner reported15.2%

* Partner reported figures, a lower bound.

Reported customs values in USD, not prices.Full trade data

The HS code shown for Triethyl phosphite 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 Triethyl phosphite, based on the data on this page

What is Triethyl phosphite?

Triethyl phosphite appears as a clear colorless liquid with a strong foul odor. Flash point 130 °F. Less dense than water and insoluble in water. Vapors heavier than air.

What is the CAS number of Triethyl phosphite?

The CAS registry number of Triethyl phosphite is 122-52-1.

What is the molecular formula and weight of Triethyl phosphite?

The molecular formula of Triethyl phosphite is C6H15O3P and its molar mass is 166.16 g/mol.

What is Triethyl phosphite used for?

Reagent in synthetic organic chemistry. Synthesis, plasticizers, stabilizers, lubricants and grease additives. Plasticizer, vinyl stabilizer, grease additive, color inhibitor for resins. Schedule 3B precursor to dimethyl methylphosphonate (which is a sarin precursor and nerve agent simulant).

Is Triethyl phosphite hazardous?

Triethyl phosphite carries the GHS signal word "Warning". Main hazards: flammable liquid and vapour, harmful if swallowed, causes skin irritation. This summary is not an SDS, always read the supplier safety data sheet.

What is the HS code of Triethyl phosphite?

Triethyl phosphite is usually classified under HS code 292024 (Triethyl phosphite). This is indicative, confirm it with your customs broker before shipping.

Can I buy Triethyl phosphite on CompoundList?

Triethyl phosphite is a controlled substance. Only documented suppliers can list it, and buyers must upload a valid licence with their request. Every request is reviewed by our compliance team before suppliers see it.

Guides for buyers

Practical guides that help when you source, ship or handle Triethyl phosphite

Request as a licensed buyer

Upload your licence with the request. Our compliance team reviews it before the documented suppliers see it.
Request as a licensed buyer
Data last updated 7 Oct 2026. Details may have changed, please confirm them with the supplier. Report an error on this page
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