Chemical Properties
Tetraethyl pyrophosphate and compressed gas mixture is a liquid charged with a gas. It is a colorless liquid. Its vapor is heavier than air. Faint, fruity, aromatic odor.
Chemical Properties
TEPP is a colorless to amber liquid. Some liquid formulation may contain flammable organic solvents. A solid (glass-like state) below 0C. May be transported in molten form. Faint, fruity, aromatic odor.
Chemical Properties
Water-white to amber liquid depending
on purity; hygroscopic. Miscible
with water and all organic solvents except aliphatic
hydrocarbons; hydrolyzed in water with formation
of mono-, di-, and triethyl orthophosphates; water
solutions attack metals; commercial material contains
40% TEPP.
Physical properties
Colorless to amber liquid with an agreeable, fruity odor
Uses
Insecticide for mites and aphids; rodenticide.
Uses
Insecticide for aphids and mites, rodenticide.
Definition
ChEBI: TEPP is an organic diphosphate.
Production Methods
Tetraethyl pyrophosphate is commercially synthesised by condensing triethyl phosphate with phosphorus oxychloride. The production process involves the controlled esterification of phosphorus oxychloride with triethyl phosphate or ethanol in the presence of a base, typically under anhydrous conditions to prevent hydrolysis. This yields tetraethyl diphosphate.
Synthesis Reference(s)
The Journal of Organic Chemistry, 15, p. 637, 1950
DOI: 10.1021/jo01149a031
General Description
Water-white to amber liquid, depending on purity.
Air & Water Reactions
Hygroscopic. Hydrolyzed in water with formation of mono. di, and triethyl orthophosphates, water solutions attack metal surfaces. Reacts slowly with water to form phosphoric acid
Reactivity Profile
Organophosphates, such as TETRAETHYL PYROPHOSPHATE, are susceptible to formation of highly toxic and flammable phosphine gas in the presence of strong reducing agents such as hydrides. Partial oxidation by oxidizing agents may result in the release of toxic phosphorus oxides.
Hazard
Toxic by skin contact, inhalation, or
ingestion; rapidly absorbed through skin; repeated
exposure may, without symptoms, be increasingly
hazardous; cholinesterase inhibitor, use may be
restricted.
Health Hazard
Highly toxic, may be fatal if inhaled, swallowed or absorbed through skin. Contact with molten substance may cause severe burns to skin and eyes. Avoid any skin contact. Effects of contact or inhalation may be delayed. Fire may produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may be corrosive and/or toxic and cause pollution.
Fire Hazard
Combustible material: may burn but does not ignite readily. Containers may explode when heated. Runoff may pollute waterways. Substance may be transported in a molten form.
Mechanism of action
Non-systemic with a brief persistence, Acetylcholinesterase (AchE) inhibitor.
Safety Profile
Human poison by ingestion and intramuscular routes. Experimental poison by ingestion, skin contact, intraperitoneal, intramuscular, subcutaneous, parenteral, and intravenous routes. Human systemic effects by ingestion, intramuscular, and parenteral routes: paresthesia, wakefulness, excitement, muscle contraction or spasticity, nausea or vomiting and other gastrointestinal changes. The action is sidar to that of parathion: causing an irreversible inhbition of the cholinesterase molecules and the consequent accumulation of large amounts of acetylcholine. Small doses at frequent intervals are largely additive. When heated to decomposition it emits toxic fumes of POx. See also PARATHION.
Potential Exposure
A potential danger to those engaged in the manufacture, formulation and application of this aphicide and acaricide; used as an insecticide to control aphids, thrips, and mites; as an anticholinesterase.
Environmental Fate
Chemical/Physical. Tetraethyl pyrophosphate is quickly hydrolyzed by water. The
hydrolysis half-lives at 25 and 38°C are 6.8 and 3.3 hours, respectively (Sittig, 1985).
Decomposes at 170–213°C releasing large amounts of ethylene (Hartley and Kidd,
1987; Keith and Walters, 1992).
Shipping
UN2810 Toxic liquids, organic, n.o.s., Hazard Class: 6.1; Labels: 6.1-Poisonous materials, Technical Name Required. UN3018 Organophosphorus pesticides, liquid, toxic, Hazard Class: 6.1; Labels: 6.1-Poisonous materials. Note: See T:0305 for TEPP 1compressd gas.
Incompatibilities
Tetraethyl pyrophosphate may be susceptible to formation of highly toxic and flammable phosphine gas in the presence of hydrides and other strong reducing agents. Partial oxidation by oxidizing agents may result in the release of toxic phosphorus oxides. Hygroscopic. Hydrolyzed in water with formation of mono. di-, and triethyl-orthophosphates. Reacts slowly with cold water forming phosphoric acid. Attacks metals in the presence of water.
Waste Disposal
Return refillable compressed gas cylinders to supplier. Consult with environmental regulatory agencies for guidance on acceptable disposal practices. Generators of waste containing this contaminant (≥100 kg/mo) must conform with EPA regulations governing storage, transportation, treatment, and waste disposal. TEPP is 50% hydrolyzed in water in 6.8 hours @ 25℃, and 3.3 hours @ 38℃; 99% hydrolysis requires 45.2 hours @ 25 ℃, or 21.9 hours @ 38℃. Hydrolysis of TEPP yields nontoxic products. Incineration is, however, an option for TEPP disposal. In accordance with 40CFR165, follow recommendations for the disposal of pesticides and pesticide containers. Must be disposed properly by following package label directions or by contacting your local or federal environmental control agency, or by contacting your regional EPA office.
Pesticide Type
Insecticide; Acaricide
