MEVINPHOS

Description

Pure mevinphos is a colourless liquid, while technical grade mevinphos is a pale yellow liquid with a very mild odour. It is soluble in water but very soluble in alcohols, ketones, chlorinated hydrocarbons, aromatic hydrocarbons, and many organic solvents. It is both an insecticide and acaricide. The U.S. EPA grouped mevinphos as an RUP, and hence it should be purchased and used only by certified and trained pesticide applicators. It is not registered for use in many countries including the United States. Mevinphos is used to control a broad spectrum of insects, including aphids, grasshoppers, leaf-hoppers, cutworms, caterpillars, and many other insects on a wide range of field, forage, vegetable, and fruit crops. It is also an acaricide that kills or controls mites and ticks. It acts quickly both as a contact insecticide, acting through direct contact with target pests, and as a systemic insecticide, which becomes absorbed by plants on which insects feed.

Chemical properties

Phosdrin is a stable, colourless, spontaneously flammable pyrophoric liquid with weak odour. It is combustible and incompatible with strong oxidising agents, corrosive to cast iron, some stainless steels, and brass.

Chemical properties

Mevinphos is a pale yellow to orange highboiling liquid. Weak odor. The carrier solvent may change the physical properties listed here.

The Uses of MEVINPHOS

Contact insecticide and acaricide for control of chewing insects and spider mites in fruits, vegetables and ornamentals.

The Uses of MEVINPHOS

Insecticide and acaricide.

The Uses of MEVINPHOS

Mevinphos is a pesticide used in the protection of crops. Insecticide.

Definition

ChEBI: Mevinphos is a dialkyl phosphate and an organophosphate insecticide. It has a role as an EC 3.1.1.7 (acetylcholinesterase) inhibitor, an acaricide, an agrochemical and an avicide. It is functionally related to a methyl 3-hydroxybut-2-enoate.

General Description

Pale yellow to orange liquid, with a weak odor. Used as an insecticide and acaricide on vegetables, alfalfa, deciduous fruits and nuts.

Air & Water Reactions

Hydrolyzes rapidly as MEVINPHOS dissolves in water.

Reactivity Profile

Organophosphates, such as MEVINPHOS, 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 ingestion, inhalation, and skinabsorption; use may be restricted; cholinesteraseinhibitor. Questionable carcinogen.

Health Hazard

MEVINPHOS is super toxic; the probable oral lethal dose for humans is less than 5 mg/kg, or a taste (less than 7 drops) for a 150-lb. person. It has direct and immediate effects whether it is swallowed, inhaled, or absorbed through the skin.

Health Hazard

A severely acute toxicant by all routes;cholinesterase inhibitor; absorbed throughthe skin, lungs, and mucous membranes;more toxic by subcutaneous or intravenousroutes than by an intraperitoneal route; toxicsymptoms include headache, weakness,blurred vision, diarrhea, and tightness inthe chest; signs of severe poisoning aresweating, salivation, lacrimation, constrictionof the pupils, depression, tremor, and convulsions; oral LD50 value (mice): 4 mg/kg;skin LD50 value (mice): 12 mg/kg; exposure limit: TLV-TWA 0.01 (～0.1 mg/m³)(ACGIH, MSHA, and OSHA).

Fire Hazard

Fire may produce irritating or poisonous gases. Runoff from fire control may give off poisonous gases and also cause pollution. When heated to decomposition, MEVINPHOS emits toxic fumes of phosphorus oxides. Avoid strong oxidizers. Avoid temperatures above 77-86F, sources of heat, fire, free flames or spark-generating equipment.

Agricultural Uses

Insecticide, Acaricide: Mevinphos is an organophosphate insecticide used to control a broad spectrum of insects, including aphids, grasshoppers, leafhoppers, cutworms, caterpillars, and many other insects on a wide range of field, forage, vegetable, and fruit crops. It is also an acaricide that kills or controls mites and ticks. It acts quickly both as a contact insecticide, acting through direct contact with target pests, and as a systemic insecticide which becomes absorbed by plants on which insects feed. Not approved for use in EU countries. Not registered for use in the U.S.

Trade name

AI3-22374®; APAVINPHOS®; CASWELL No. 160B®; CENTURY-CIDE®[C]; COMPOUND 2046®; DURHAM®[C]; EXCELCIDE®[C]; GESFID®; GESTID®; PD 5®; HELENA PHOSDRIN®[C]

Contact allergens

Sensitization to mevinphos (also named Duraphos, Phosdrin, and Phosfene), an organophosphate cholinesterase inhibitor that is used as an insecticide, was rarely reported.

Safety Profile

Poison by ingestion, inhalation, skin contact, subcutaneous, intravenous, and intraperitoneal routes. Human systemic effects by ingestion: peripheral motor nerve recording changes. An insecticide. When heated to decomposition it emits toxic fumes of POx.

Potential Exposure

Those engaged in the manufacture, formulation, and application of this super toxic contact and systemic insecticide and acaricide.

First aid

If this chemical gets into the eyes, remove anycontact lenses at once and irrigate immediately for at least15 min, occasionally lifting upper and lower lids. Seek medical attention immediately. If this chemical contacts theskin, remove contaminated clothing and wash immediatelywith soap and water. Speed in removing material from skinis of extreme importance. Shampoo hair promptly if contaminated. Seek medical attention immediately. If thischemical has been inhaled, remove from exposure, beginrescue breathing (using universal precautions, includingresuscitation mask) if breathing has stopped and CPR ifheart action has stopped. Transfer promptly to a medicalfacility. When this chemical has been swallowed, get medical attention. Give large quantities of water and inducevomiting. Do not make an unconscious person vomit

Environmental Fate

Plant. In plants, mevinphos is hydrolyzed to phosphoric acid dimethyl ester, phosphoric acid and other less toxic compounds (Hartley and Kidd, 1987). In one day, the compound is almost completely degraded in plants (Cremlyn, 1991). Casida et al. (1956) proposed two degradative pathways of mevinphos in bean plants and cabbage. In the first degradative pathway, cleavage of the vinyl phosphate bond affords methylacetoacetate and acetoacetic acid which may be precursors to the formation of the end products dimethyl phosphoric acid, methanol, acetone and carbon dioxide. In the other degradative pathway, direct hydrolysis of the carboxylic ester would yield vinyl phosphates as intermediates. The halflife of mevinphos in bean plants was 12 hours (Casida et al., 1956). In alfalfa, the halflife was 17 hours (Huddelston and Gyrisco, 1961).
Chemical/Physical. The reported hydrolysis half-lives of cis-mevinphos and transmevinphos at pH 11.6 are 1.8 and 3.0 hours, respectively (Casida et al., 1956). The volatility half-lives for the cis and trans forms at 28°C were 21 and 24 hours, respectively (Casida et al., 1956). Worthing and Hance (1991) reported that at pH values of 6, 7, 9 and 11, the hydrolysis half-lives were 120 days, 35 days, 3.0 days and 1.4 hours, respectively (Worthing and Hance, 1991).
Emits toxic phosphorus oxide fumes when heated to decomposition (Lewis, 1990).

storage

Color Code—Blue: Health Hazard/Poison: Storein a secure poison location. Prior to working with thischemical you should be trained on its proper handling andstorage. Store in tightly closed containers in a cool, wellventilated area away from oxidizers.

Shipping

UN3018 Organophosphorus pesticides, liquid, toxic, Hazard Class: 6.1; Labels: 6.1-Poisonous materials. UN2783 Organophosphorus pesticides, solid, toxic, Hazard Class: 6.1; Labels: 6.1-Poisonous material.

Toxicity evaluation

Acute oral LD₅₀ for rats is 3–12 mg/kg.Inhalation LC50 (1 h) for rats is 0.125 mg/L air. No ill effects were observed in rats receiving 4 mg/kg diet (0.2 mg/kg/d) for 2 yr. ADI is 1.5 μg/kg b.w. In comparison with the Z-isomer, E-mevinphos is a more effective insecticide and is detoxified more quickly in plants but more slowly in animals.

Incompatibilities

Decomposes in heat (below boiling point @ 300℃) producing phosphoric acid and phosphorous oxides fumes. Strong oxidizers may cause release of toxic phosphorus oxides. Organophosphates, in the presence of strong reducing agents such as hydrides, may form highly toxic and flammable phosphine gas. Keep away from alkaline materials. Corrosive to cast iron, some stainless steels and brass. Attacks some forms of plastics, rubber and coatings.

Waste Disposal

Mevinphos is 50% hydrolyzed in aqueous solutions at an unspecified temperature in 1.4 hours at pH 11, 35 days at pH 7; and 120 days at pH 6. Thermal decomposition is rapidly accomplished by lime sulfur. Mevinphos may also incinerated. 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.