CLASSIFICATION: Pesticide (insecticide, molluscicide)
DESCRIPTION: Azinphos methyl was initially registered as a pesticide under FIFRA in 1957. All Azinphos methyl liquids with a concentration greater than 13.5% are classified as Restricted Use Pesticides (RUP) by the U. S. Environmental Protection Agency (EPA), because of the human inhalation hazard and acute toxicity presented by this material, as well as its potential adverse effects to other mammalian species, birds, and aquatic organisms. RUPs may be purchased and used only by certified applicators. A registration standard was issued for Azinphos methyl in September, 1986. The EPA has imposed a 24-hour reentry interval for this material. Areas that have been treated with Azinphos methyl may not be reentered for at least 24 hours, unless protective clothing is worn. Products containing Azinphos methyl must bear the signal words "Danger" and "Poison”. Check with specific state regulations for local restrictions, which may apply. Azinphos methyl is a highly persistent, broad-spectrum insecticide. It is also an acaricide, toxic to mites and ticks, and a molluscicide, poisonous to snails and slugs. It is one of a group of organic compounds called organophosphates because of the presence of phosphorous in their molecular structures. It is a nonsystemic material, meaning that it is not transported from one plant part to another. It is used primarily as a foliar application against leaf-feeding insects. It works as both a contact insecticide and a stomach poison. Contact poisons are effective upon contact with any part of the target organism. Stomach poisons become toxic when an insect eats them. Azinphos methyl is used for the control of many insect pests on a wide variety of fruit, vegetable, nut, and field crops, as well as on ornamentals, tobacco, and forest and shade trees Outside of the U.S., Azinphos methyl is used in lowland rice production. On 1986, approximately three million pounds of this active ingredient were used against more than 200 pests on about 50 different sites. Azinphos methyl is available in emulsifiable liquid, liquid flowable, ULV liquid, and wettable powder formulations. An organophosphate insecticide first registered in 1959, azinphos-methyl is widely used in agriculture and provides important pest control benefits to growers of orchard fruit, nut, and other crops. However, Azinphos-methyl also poses a high degree of risk to agricultural workers, as well as significant acute ecological risks.
HEALTH PROBLEMS: Azinphos methyl is one of the most toxic of the organophosphate insecticides. It is highly toxic by inhalation, dermal absorption, ingestion, and eye contact. Like all organophosphate chemicals, Azinphos methyl is referred to as a "cholinesterase inhibitor." It binds up, blocks, or damages, the normal functioning of cholinesterase, an enzyme that is essential to the proper working of the nervous system. Individuals with a history of reduced lung function, convulsive disorders, or recent exposure to other cholinesterase inhibitors will be at increased risk from exposure to Azinphos methyl. The organophosphate insecticides are cholinesterase inhibitors. They are highly toxic by all routes of exposure. When inhaled, the first effects are usually respiratory and may include bloody or runny nose, coughing, chest discomfort, difficult or short breath, and wheezing due to constriction or excess fluid in the bronchial tubes. Azinphos methyl is easily absorbed by the skin. Skin contact with organophosphates may cause localized sweating and involuntary muscle contractions. Eye contact will cause pain, bleeding, tears, pupil constriction, and blurred vision. Following exposure by any route, other systemic effects may begin within a few minutes or be delayed for up to 12 hours. These include pallor, nausea, vomiting, diarrhea, abdominal cramps, headache, dizziness, eye pain, blurred vision, constriction or dilation of the eye pupils, tears, salivation, sweating, and confusion. Severe poisoning will affect the central nervous system, producing incoordination, slurred speech, loss of reflexes, weakness, fatigue, involuntary muscle contractions, twitching, tremors of the tongue or eyelids, and eventually paralysis of the body extremities and the respiratory muscles. In severe cases, there may also be involuntary defecation or urination, psychosis, irregular heartbeats, unconsciousness, convulsions and coma. Death may be caused by respiratory failure or cardiac arrest