Vamidothion

Fresh air, rest. Half-upright position. Artificial respiration may be needed. Refer for medical attention.

Remove contaminated clothes. Rinse and then wash skin with water and soap. Refer for medical attention .

First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention.

Rinse mouth. Induce vomiting (ONLY IN CONSCIOUS PERSONS!). Refer for medical attention .

Biological Exposure Indices (BEI) [ACGIH] - Acetylcholinesterase activity in red blood cells = 70% of individual's baseline; Butylcholinesterase activity in serum or plasma = 60% of individual's baseline; Sample at end of shift; [TLVs and BEIs]

If material on fire or involved in fire: Do not extinguish fire unless flow can be stopped or safely confined. Use water in flooding quantities as fog. Solid streams of water may be ineffective. Cool all affected containers with flooding quantities of water. Apply water from as far a distance as possible. Use "alcohol" foam, carbon dioxide or dry chemical. /Organophosphorus pesticides, liquid, NOS/

If material on fire or involved in fire: Use water in flooding quantities as fog. Extinguish fire using agent suitable for type of surrounding fire. (Material itself does not burn or burns with difficulty.) Use foam, dry chemical. or carbon dioxide. /Organophosphorus pesticides, solid, NOS/

Environmental considerations: Land spill: Dig a pit, pong, lagoon, holding area to contain liquid or solid material. /SRP: If time permits, pits, ponds, lagoons, soak holes, or holding areas should be sealed with an impermeable flexible membrane liner./ Dike surface flow using soil, sand bags, foamed polyurethane, or foamed concrete. Absorb bulk liquid with fly ash, cement powder, or commercial sorbents. /Organophosphorus pesticides, solid, NOS/

Environmental considerations: Water spill: use natural barriers or oil spill control booms to limit spill travel. Remove trapped material with suction hoses. /Organophosphorus pesticides, solid, NOS/

Environmental considerations: Air spill: Apply water spray or mist to knock down vapors. /Organophosphorus pesticides, solid, NOS/

Environmental considerations: Land spill: Dig a pit, pong, lagoon, holding area to contain liquid or solid material. /SRP: If time permits, pits, ponds, lagoons, soak holes, or holding areas should be sealed with an impermeable flexible membrane liner./ Dike surface flow using soil, sand bags, foamed polyurethane, or foamed concrete. /Organophosphorus pesticides, liquid, NOS/

For more Cleanup Methods (Complete) data for VAMIDOTHION (6 total), please visit the HSDB record page.

SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational exposure or environmental contamination. Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in soil or water; effects on animal, aquatic, and plant life; and conformance with environmental and public health regulations.

Personal protection: particulate filter respirator adapted to the airborne concentration of the substance. Sweep spilled substance into covered containers. If appropriate, moisten first to prevent dusting. Carefully collect remainder. Do NOT wash away into sewer. Then store and dispose of according to local regulations.

If material not on fire and not involved in fire: Keep sparks, flames, and other sources of ignition away. Keep material out of water sources and sewers. Build dikes to contain flow as necessary. Attempt to stop leak if without undue personnel hazard. Use water spray to knock-down vapors. /Organophosphorus pesticides, liquid, NOS/

Personnel protection: Avoid breathing vapors. Keep upwind. ... Avoid bodily contact with the material. ... Do not handle broken packages unless wearing appropriate personal protective equipment. Wash away any material which may have contacted the body with copious amounts of water or soap and water. /Organophosphorus pesticides, liquid, NOS/

If material not on fire and not involved in fire: Keep sparks, flames, and other sources of ignition away. Keep material out of water sources and sewers. /Organophosphorus pesticides, solid, NOS/

Personnel protection: Avoid breathing dusts, and fumes from burning material. Keep upwind. ... Avoid bodily contact with the material. ... Do not handle broken packages unless wearing appropriate personal protective equipment. Wash away any material which may have contacted the body with copious amounts of water or soap and water. /Organophosphorus pesticides, solid, NOS/

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 810(SRC), determined from a structure estimation method(2), indicates that vamidothion is expected to have low mobility in soil(SRC). Volatilization of vamidothion from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 8.6X10-16 atm-cu m/mole(SRC), using a fragment constant estimation method(3). Vamidothion is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 1.4X10-6 mm Hg(SRC), determined from a fragment constant method(4). Vamidothion is expected to biodegrade in the environment based on an observed half-life of 1-1.5 days in soil at 22 °C(5).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 810(SRC), determined from a structure estimation method(2), indicates that vamidothon is expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is not expected(3) based upon an estimated Henry's Law constant of 8.6X10-16 atm-cu m/mole(SRC), developed using a fragment constant estimation method(4). According to a classification scheme(5), an estimated BCF of 3.2(SRC), from an estimated log Kow of 0.16(6) and a regression-derived equation(7), suggests the potential for bioconcentration in aquatic organisms is low(SRC). Vamidothion is expected to biodegrade in the environment based on an observed half-life of 1-1.5 days in soil at 22 °C(8).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), vamidothion, which has an estimated vapor pressure of 1.4X10-6 mm Hg at 25 °C(SRC), determined from a fragment constant method(2), is expected to exist solely in the particulate phase in the ambient atmosphere. Vapor-phase vamidothion is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals(SRC); the half-life for this reaction in air is estimated to be 2.8 days(SRC), calculated from its rate constant of 5.8X10-11 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). Particulate-phase vamidothion may be removed from the air by wet or dry deposition(SRC). Vamidothion, present at a concn of 100 mg/L in distilled water with 2-4% methanol, degraded only 2% after 6 hours during an aqueous photolysis test which used a suntest apparatus consisting of a xenon arc lamp emitting 300-800 nm of light(4), suggesting that vamidothion is not susceptible to direct photolysis(SRC).

Pupillary constriction, muscle cramp, excessive salivation. Sweating. Nausea. Dizziness. Laboured breathing. Convulsions. Unconsciousness.

MAY BE ABSORBED! See Inhalation.

Abdominal cramps. Vomiting. Diarrhoea. Further see Inhalation.

Workers handling & applying pesticides must undergo an annual medical examination at the beginning of each agricultural season. Contraindications for work with /organophosphorus pesticides/ are organic diseases of the central nervous system, mental disorders & epilepsy, pronounced endocrine & vegetative disorders, pulmonary tuberculosis, bronchial asthma, chronic respiratory diseases, cardiovascular diseases & circulatory disorders, gastrointestinal diseases (peptic ulcer), gastroenterocolitis, diseases of liver & kidneys, eye diseases (chronic conjunctivitis & keratitis). The blood cholinesterase activity must be determined before work starts. In the event of prolonged work periods, this activity should be determined at intervals of 3-4 days. Persons exhibiting a fall in cholinesterase activity of 25% or more must be transferred to other work where they are not exposed to organophosphorus pesticides until this activity is completely restored. Persons with initial signs of indisposition should cease work with pesticides. /Organophosphorus pesticides/

A final diagnosis of mild to moderate acute organophosphate pesticide poisoning is rarely justified unless all of the following five conditions are present: 1. A definite history of exposure to an organophosphate pesticide. 2. A latent interval of not more than a few hours between that last exposure and the onset of illness. 3. A clinical picture in which most or all of the following signs or symptoms are present: headache, blurred vision, weakness, tightness in chest, and constricted pupils. 4. Reduction of plasma and RBC cholinesterase activity to a level substantially below 50% of baseline values. Because of the wide normal range of RBC cholinesterase in the population, symptoms may be present with reported "normal" levels. 5. An acute illness that is not substantially longer than 48 hours. The classic presentation for acute organophosphate toxicity includes history, evidence of exposure to organophosphate (garlic odor), signs/symptoms of cholinergic excess, improvement with atropine or pralidoxime, and inhibition of cholinesterase in blood. /Organophosphate pesticide poisoning/

Using a structure estimation method based on molecular connectivity indices(1), the Koc of vamidothion can be estimated to be 810(SRC). According to a classification scheme(2), this estimated Koc value suggests that vamidothion is expected to have low mobility in soil.

/HUMAN EXPOSURE STUDIES/ Eighteen people using vamidothion on crops were examined. The concentration of the product in air was 0.024 mg/cu m 50 meters away from the point of application. Symptoms recorded were a very slight drop in pulse rate and arterial blood pressure in 8 subjects. For 10 minutes, a reduction of 4-11% in blood cholinesterase was observed.

/SIGNS AND SYMPTOMS/ Organophosphate insecticides ... are potent cholinesterase enzyme inhibitors that act by interfering with the metabolism of acetylcholine, which results in accumulation of acetylcholine at neuroreceptor transmission sites. Exposure produces a broad spectrum of clinical effects indicative of massive overstimulation of the chlorinergic system, including muscarinic effects (parasympathetic), nicotinic effects (sympathetic and motor), and CNS effects. These effects present clinically as feeling of headache, weakness, dizziness, blurred vision, psychosis, respiratory difficulty, paralysis, convulsions, and coma. Typical findings are given by the mnemonic "SLUD." which stands for salivation, lacrimation, urination, and defecation. A small percentage of patients may fail to demonstrate miosis, a classic diagnostic hallmark. Onset of clinical manifestation of organophosphate poisoning usually occurs within 12 hours of exposure. /Organophosphate insecticides/

/SIGNS AND SYMPTOMS/ A follow up study of 232 people three years after a history of organophosphorus pesticide poisoning disclosed only one person with slight residual blurring of vision that might have been related to the earlier poisoning, though at the time of poisoning over one third of the people had blurring, which lasted only a day or two after exposure was discontinued. The possible exceptional case had findings suggestive of basilar artery insufficiency, rather than effects of poisoning. /Organophosphorus pesticide poisoning/

/SIGNS AND SYMPTOMS/ The duration of illness depends on the severity of poisoning, since several months may be required for cholinesterase activity to return to normal levels. Symptoms of mild to moderate organophosphate poisoning usually resolve by 1 month. A follow up study of pesticide workers who developed acute organophosphate poisoning revealed that episodes of headache, visual disturbances, nausea, and vomiting persisted 10 weeks after the acute episode, but the effect of reexposure to organophosphates could not be evaluated. /Organophosphate pesticide/

For more Human Toxicity Excerpts (Complete) data for VAMIDOTHION (11 total), please visit the HSDB record page.

Used as systemic acaricide and insecticide for fruit trees, vines, ornamentals, beets, potatoes, cotton, rice, and other crops; Registered for use in many other countries; [HSDB]

No longer registered as a pesticide for use in the US; [HSDB] Banned in the EU for use as a biocide and agricultural insecticide; [eChemPortal: ESIS]

Farming (Pesticides) [Category: Industry]

Aphicide; miticide

It is a systemic acaricide and insecticide.

Used on fruit trees, vines, ornamentals, beet, potatoes, cotton, rice, etc for persistent control of all species of aphids (especially woolly aphids), thrips, sawfly larvae, psyllids, spider mites, etc.

Vamidothion is produced by reaction of O,O-dimethylphosphoric acid chloride with the sodium salt of N-methylcarbamylethylmercaptoethanethiol.

... 2-Chloroethanol (ethylene chlorohydrin) is reacted with ethyl 2-mercapto propionate giving ethyl-2-(2-hydroxyethylthio)propionate. That intermediate is, in turn treated successively with methylamine and thionyl chloride to give 2-(2-chloroethylthio)-N-methylpropionamide. Condensation with O,O-dimethylphosphorothioate gives vamidothion.

Emulsifiable solution.

Emulsifiable concentrate

Soluble concentrate (400 g ai/l)

The WHO Recommended Classification of Pesticides by Hazard identifies Vamidothion (technical grade) as Class IB: highly hazardous; Main Use: insecticide.

Not registered for use /in the United States/; Registered in many countries for cotton, hop, orchards, rice, sugarcane, vegetables, ornamentals; leafhoppers on rice.