Малатион

Описание

Malathion, a clear amber liquid, is sparingly soluble in water but soluble in a majority of organic solvents. The U.S. Environmental Protection Agency (U.S. EPA) grouped malathion under GUP, meaning general use pesticide. It is used as an insecticide as well as an acaricide for the control of pests. Malathion is used for the control of sucking insects and chewing insects on fruits and vegetables. Malathion is an effective insecticide for the control of several household pests such as houseflies, cockroaches, mosquitoes, aphids, animal ectoparasites, and human head and body lice. Malathion is also found in formulations with many other pesticides.

Химические свойства

Malathion is a deep-brown to yellow liquid with a garlic-like odor. Clear and colorless when pure; freezing/melting point5 3C;

Физические свойства

Clear, yellow to yellow-orange to brown liquid with an unpleasant garlic, skunk, or mercaptanslike odor

Использование

Malathion is used to control a wide spectrum of insect pests in many types of crops and disease vectors in public health programmes. It is also used to control ectoparasites of both humans and animals.

Определение

ChEBI: A diester that is butanedioate substituted by a (dimethoxyphosphorothioyl)sulfanediyl group at position 2.

Показания

Malathion (Ovide) is highly effective in the prevention and treatment of pediculosis. It displays 95% ovicidal activity and has no scabicidal activity. It works through cholinesterase inhibition.

Общее описание

Malathion, 2-[(dimethoxyphosphinothioyl)thio]butanedioic acid diethyl ester, is a water-insolublephosphodithioate ester that has been used as an agriculturalinsecticide. Malathion is a poor inhibitor of cholinesterases.Its effectiveness as a safe insecticide is a result of the differentrates at which humans and insects metabolize the chemical.Microsomal oxidation, which causes desulfuration,occurs slowly to form the phosphothioate (malaoxon),which is 10,000 times more active than the phosphodithioate(malathion) as a cholinesterase inhibitor. Insects detoxifythe phosphothioate by a phosphatase, forming dimethylphosphorothioate, which is inactive as an inhibitor.Humans, however, can rapidly hydrolyze malathion by acarboxyesterase enzyme, yielding malathion acid, a stillpoorer inhibitor of AChE. Phosphatases and carboxyesterasesfurther metabolize malathion acid to dimethylphosphothioate.

Реакции воздуха и воды

Insoluble in water.

Профиль реактивности

Malathion is a yellow to brown liquid that solidifies at 2.9° C, moderately toxic. Organic phosphate insecticide, acts as an inhibitor of cholinesterase. When heated to decomposition Malathion emits toxic fumes of oxides of sulfur and phosphorus [Lewis, 3rd ed., 1993, p. 789].

Опасность

Absorbed by skin, cholinesterase inhibitor. Questionable carcinogen.

Угроза здоровью

Cholinesterase inhibitor; toxic propertiessimilar to those of parathion; however,less toxic than parathion; moderately toxicby ingestion and possibly other routes ofexposure; toxic symptoms include excessivesalivation, lacrimation, blurred vision, con-striction of the pupils, nausea, vomiting,abdominal pain, and difficulty in breathing;also coma and death can result form largeintake; ingestion of 10–25 g could be fatalto adult humans; skin contact can produceallergic sensitization reaction; also absorbedthrough skin, causing systemic poisoning;experimental teratogen; LD50 data reportedin the literature show wide variation.
LD50 oral (rate): 300–2800 mg/kg
LD50 skin (mouse): 2000–3000 mg/kg
Benslama et al. (2004) have reported twounusual cases of malathion poisoning with arare-type of complication from “intermediatesyndrome” arising 2 to 4 days after the onsetof cholinergic effects. The symptoms wererespiratory paresis with difficulties of wean-ing from assisted respiratory, deficit of proximal limbs, neck flexors and cranial nerves.The authors attributed this syndrome to pro-longed inhibition of acetyl-cholinesterasesand not to any muscular fiber’s necrosis.

Сельскохозяйственное использование

nsecticide: Not approved for use in EU countries. Malathion is a non-systemic, wide-spectrum organophosphate insecticide. It was one of the earliest organophosphate insecticides developed (introduced in 1950). Malathion is suited for the control of sucking and chewing insects on fruits, vegetables, citrus, cotton, corn, sorghum, ornamentals and stored products, and is also used to control mosquitoes, flies, household insects, farm and livestock parasites (ectoparasites), and head and body lice. Malathion may also be found in formulations with many other pesticides; the U.S. EPA lists 2,283 current and canceled labels of products containing malathion. Malathion is marketed as 99.6% technical grade liquid. Available formulations include wettable powders (25% and 50%), emulsifiable concentrates, dusts and aerosols.

Торговое название

AI3-17034®; AGRICHEM GREENFLY SPRAY®; ALCO® Malathion; ALL PURPOSE GARDEN INSECTICIDE®; AMERICAN CYANAMID 4,049®; ATRAPA 5E®; BAN-MITE®; CALMATHION®; CARBETOVUR®; CARBETOX®; CELTHION®; CHEMATHION®; CIMEXAN®; COMPOUND 4049®; CROMOCIDE®; CYTHION®; SPRAY CONCENTRATE®; CYTHION®; DETMOL MA®; DETMOL® 96%; DETMOL MALATHION®; DURAMITEX®; EMMATOS EXTRA®; EL 4049®; EMMATON®; EMMATOS®; ETIOL®; EVESHIELD CAPTAN/MALATHION®; EXATHIOS®; EXTERMATHION®; FYAFANON®; FISONS GREENFLY AND BLACKFLY KILLER®; FOG® 3; FORMAL®; FORTHION®; FOSFOTHION®; FOSFOTION®; FYFANON®; ETHIOLACAR®; GREEN DEVIL®; GREENFLY AEROSOL SPRAY®; HILTHION®; KARBOFOS®; KOPTHION ®; KYPFOS®; MALACIDE®; MALAFOR®; MALAGRAN®; MALAKILL®; MALAMAR®; MALASOL®; MALASPRAY®; MALATAF®; MALATHION 60®; MALATHION E50®; MALATOL®; MALTOX®; MOSCARDA®; ORTHO MALATHION®; PBI CROP SAVER®; PRENTOX®; PRIODERM®; PROKIL® Malathion; SADOFOS®; SADOPHOS®; SF® 60; SIPTOX I®; SUMITOX®; TAK®; TM-4049®; VETIOL®; ZITHIOL®

Контактные аллергены

This organophosphorus pesticide is used as an insecticide and an acaricide, particularly against head lice. Sensitization was reported in farmers.

Профиль безопасности

A human poison by ingestion and skin contact. Can penetrate intact skin. An experimental poison by ingesuon, inhalation, intraperitoneal, intravenous, intraarterial, and subcutaneous routes. Human systemic effects by ingestion: coma, blood pressure depression, and dfficulty in breathmg. Questionable carcinogen. An experimental teratogen. Other experimental reproductive effects. Human mutation data reported. Has caused allerglc sensitization of the skin. An organic phosphate cholinesterase inhibitor. When heated to decomposition it emits toxic fumes of POx and SOx. See also PHOSPHATES and PARATHION.

Возможный контакт

Malathion is marketed as 99.6% technical grade liquid. Available formulations include wetable powders (25% and 50%), emulsifiable concentrates, dusts, and aerosols. Malathion is used as a broad spectrum insecticide and acaricide in the control of certain insect pests on fruits, vegetables, and ornamental plants. It has been used in the control of houseflies, mosquitoes, lice; and on farm and livestock animals.

Канцерогенность

There was no evidence of carcinogenicity in rats given diets that contained 4700 or 8150 ppm (about 270 mg/kg and 466 mg/kg) for 80 weeks and observed for an additional 33 weeks, in rats given diets that contained 2000 or 4000 ppm malathion (about 115 mg/ kg/day and 230 mg/kg/day) for 103 weeks, or in rats given diets that contained 500 or 1000 ppm malaoxon for 103 weeks .

Перевозки

UN2783 Organophosphorus pesticides, solid, toxic, Hazard Class: 6.1; Labels: 6.1-Poisonous materials

Несовместимости

Reacts violently with strong oxidizers, magnesium, alkaline pesticides. Attacks metals including iron, steel, tin plate; lead, copper; and some plastics, coatings, and rubbers

Утилизация отходов

Malathion is reported to be “hydrolyzed almost instantly” at pH 12; 50%; hydrolysis at pH 0 requires 12 hours. Alkaline hydrolysis under controlled conditions (0.5 n NaOH in ethanol) gives quantitative yields of (CH3O)2P(S)SNa, whereas hydrolysis in acidic media yields (CH3O)2P(S)OH. On prolonged contact with iron or iron-containing material, it is reported to break down and completely lose insecticidal activity. Incineration together with a flammable solvent in a furnace equipped with afterburner and scrubber is recommended. 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