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<br /> ;XT TET PIP - METHOMYL
<br /> EXTOXNET
<br /> --.:, Extension Toxicology Network
<br /> Pesticide Information Profiles
<br /> A Pesticide Information Project of Cooperative Extension Offices of Cornell University, Oregon State University,
<br /> the University of Idaho, and the University of California at Davis and the Institute for Environmental Toxicology,
<br /> Michigan State University. Major support and funding was provided by the USDA/Extension Service/National
<br /> Agricultural Pesticide Impact Assessment Program.
<br /> i
<br /> EXTOXNET primary files maintained and archived at Oregon State University
<br /> Revised June 1996
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<br /> .-Methomyl
<br /> ' Trade and Other Names: Common names include metomil and mesomile. Trade names include Acinate,
<br /> Agrinate, DuPont 1 I79, Flytek, Kipsin,,Lannate,Lanox, Memilene, Methavin, Methornex,Nudrin,NuBait,
<br /> Pillarmate and SD 14999.
<br /> Regulatory Status: Methomyl is a highly toxic compound in EPA toxicity class I. It is classified as Restricted
<br /> Use Pesticide (RUP)by EPA because of its high acute toxicity to humans. The Signal Words for products
<br /> containing methomyl depend upon the formulation of the product. Restricted Use Pesticides may be purchased and
<br /> used only by certified applicators. Reentry periods for farm workers of I to 7 days are required, depending on the
<br /> crop.
<br /> Chemical: Class: carbamate
<br /> Introduction: Methomyl was introduced in 1966 as a broad spectrum insecticide. It is also used as an acaricide
<br /> fruit and field cro s cotton, commercial
<br /> Co control ticks and spiders. It is used for foliar treatment of vegetable, p ,
<br /> t ornamentals, and in and around poultry houses and dairies. It is also used as a fly bait. Methomyl is effective in two
<br /> R ways: (a) as a"contact insecticide," because it kills target insects upon direct contact, and (b) as a "systemic
<br /> insecticide" because of its capability to cause overall "systemic" poisoning in target insects, after it is absorbed and
<br /> transported throughout the pests that feed on treated plants. It is capable of being absorbed by plants without being
<br /> "phytotoxic" or harmful, to the plant.
<br /> Formulation:Not Available
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<br /> Toxicological Effects:
<br /> . Acute toxicity: Methomyl is highly toxic via the oral route, with reported oral LD50 values of 17 to 24 mg/kg
<br /> in rats [10], 10 mg/kg in mice, and 15 mg/kg in guinea pigs [5]. Symptoms of methomyl exposure are similar
<br /> to those caused by other carbamates and cholinesterase inhibitors [5]. These may include weakness, blurred
<br /> vision, headache, nausea, abdominal cramps, chest discomfort, constriction of pupils, sweating, muscle
<br /> tremors, and decreased pulse. If there is severe poisoning, symptoms of twitching, giddiness, confusion,
<br /> muscle incoordination, slurred speech, low blood pressure, heart irregularities, and loss of reflexes may also
<br /> be experienced. Death can result from discontinued breathing, paralysis of muscles of the respiratory system,
<br /> intense constriction of the openings of the lung, or all three [5]. It is moderately toxic via inhalation with a
<br /> reported 4-hour inhalation LC50 in male rats of 0.3 mg/L [4]. Inhalation of dust or aerosol may cause
<br /> irritation, lung and eye problems, with symptoms of chest tightness, blurred vision, tearing, wheezing, and
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