- MERPHOS
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2025-04-04
- CAS:150-50-5
- Min. Order: 1kg
- Purity: 98%
- Supply Ability: 1Ton
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| | MERPHOS Basic information |
| Product Name: | MERPHOS | | Synonyms: | TRIBUTYLPHOSPHORO-TRITHIOITE;Butyl phosphorotrithioite ((bus)3p);butylphosphorotrithioite;butylphosphorotrithioite[(bus)3p];Deleaf defoliant;deleafdefoliant;Easy off-D;easyoff-d | | CAS: | 150-50-5 | | MF: | C12H27PS3 | | MW: | 298.51 | | EINECS: | 205-761-4 | | Product Categories: | Agro-Products;Sulfur & Selenium Compounds | | Mol File: | 150-50-5.mol |  |
| | MERPHOS Chemical Properties |
| Melting point | 100°C | | Boiling point | 115-134 °C(Press: 0.08 Torr) | | density | 1.0200 | | solubility | Chloroform (Slightly), Dichloromethane (Slightly), Diethyl Ether (Slightly) | | form | Liquid | | Henry's Law Constant | 4.3×10-1 mol/(m3Pa) at 25℃, HSDB (2015) | | Stability: | Air Sensitive, Hygroscopic, Moisture Sensitive | | EPA Substance Registry System | Merphos (150-50-5) |
| RIDADR | 3278 | | TSCA | TSCA listed | | HazardClass | 6.1(b) | | PackingGroup | III | | Hazardous Substances Data | 150-50-5(Hazardous Substances Data) | | Toxicity | guinea pig,LD50,oral,850mg/kg (850mg/kg),Gigiena i Sanitariya. For English translation, see HYSAAV. Vol. 27(8), Pg. 97, 1962. |
| | MERPHOS Usage And Synthesis |
| Chemical Properties | Nearly colorless liquid. Insoluble in water; soluble in a variety of organic
solvents. | | Uses | Merphos is an organothiophosphorus compound used as
a defoliant but the active ingredient is no longer contained in
any registered pesticide product in the US and in EU. Therefore,
Environmental Protection Agency (EPA) is characterizing it as
canceled.
The status of merphos in the EU pesticide database is ‘Not
Approved’ under the Regulation EC 1107/2009 and not
authorized at national level in EU countries. However
a maximum level of residues (MRL) is regulated in foods as the
default MRL of 0.01 mg kg-1 according to Art 18(1)(b) Reg
396/2005.
Merphos was used to defoliate cotton at application rates
of 1.1–2.2 kg active ingredient per acre and can induce leaf
abscission in some other plants, such as roses and hydrangeas.
It was particularly suited for total defoliation of cotton
preparatory to machine harvesting because the natural action
of the substance causes the leaves to drop in a relatively green
state with fresh weight adequate to cause them to fall to the
ground.
The technical product used to have 95% purity. Formulation
used to contain 720 g active ingredient per liter or being an
emulsifiable concentrate containing 6 lb per gallon. | | Uses | Organophosphate pesticide used in the agriculture industry | | Production Methods | The industrial production of merphos begins with the preparation of phosphorotrithioic acid or its reactive derivatives, which serve as the phosphorus-containing core. This compound undergoes esterification with butyl alcohols (typically n-butanol or isobutanol) under controlled conditions, often in the presence of acid catalysts such as sulphuric acid or p-toluenesulfonic acid. The reaction is carried out in organic solvents like toluene or xylene, with temperature and pH carefully regulated to ensure complete conversion and minimise side reactions. The resulting tributyl ester is purified through distillation or solvent extraction to remove unreacted materials and achieve the desired chemical purity. | | General Description | Emulsifiable oil. | | Reactivity Profile | Organothiophosphates, such as MERPHOS, 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 | Cholinesterase inhibitor. | | Mechanism of action | Merphos, as a defoliant pesticide, works by causing a controlled injury to the leaf tissue of cotton plants. This injury triggers a stress response in the plant, leading to the production of ethylene, a plant hormone that plays a crucial role in leaf senescence and abscission. | | Safety Profile | Poison by
intraperitoneal route. Moderately toxic by
ingestion and skin contact. A cholinesterase
inhibitor. Combustible when exposed to
heat or flame. Can react vigorously with
oxidzing materials. When heated to
decomposition it emits highly toxic fumes of
POx and SOx. Used as a defoliant. See also
PARATHION. | | Environmental Fate | Merphos is adsorbed strongly to soil and oxidized to
S,S,S-tributyl phosphorotrithioate (DEF). The Koc estimated for
merphos is theoretically 62 000; accordingly, merphos would
be immobile in soil.
In water, merphos will be oxidized to DEF. The fact that
merphos is expected to adsorb strongly to particulate matter in
the water column, apparently did not impede its oxidation.
In the atmosphere, merphos will exist as an aerosol and be
removed by gravitational settling and readily oxidized to DEF.
Vapor-phase merphos will react with photochemically
produced hydroxyl radicals, with an estimated half-life of 4.9 h. | | Pesticide Type | Plant Growth Regulator; Herbicide |
| | MERPHOS Preparation Products And Raw materials |
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