732-11-6 Usage
Description
Phosmet is an organophosphate insecticide and acaricide that is effective in controlling a wide range of insects and mites in various crops and as a veterinary ectoparasiticide.
Used in Agriculture:
Phosmet is used as a nonsystemic acaricide and insecticide for the protection of citrus, fruit, grape, and potato crops. It helps reduce apple damage caused by various insects, such as apple maggots, codling moths, and obliquebanded leafrollers, when applied as a border or cover spray at a concentration of 1.9 kg AI/hectare.
Used in Veterinary Medicine:
Phosmet is used as a 20% pour-on solution to control S. scabiei in pigs, serving as an effective veterinary ectoparasiticide.
Used in Crop Protection:
Phosmet is used as a pesticide to protect a wide range of crops, including fruit, potatoes, sweet potatoes, vines, cotton, and many others, by controlling insects and mites that can cause significant damage.
Used as Insecticide and Acaricide:
Phosmet is utilized as both an insecticide and acaricide, playing a crucial role in managing and preventing infestations in various agricultural settings.
Reactivity Profile
Organophosphates, such as Phosmet, 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. Storage above 113 F, may lead to decomposition. [EPA, 1998].
Health Hazard
Phosmet is an organophosphorus pesticide. Phosmet is very toxic; the probable oral lethal dose for humans is 50-500 mg/kg, or between 1 teaspoon and 1 oz. for a 150 lb. person. It is a cholinesterase inhibitor and has central nervous system effects. Oral lethal doses in humans have been reported at 50 mg/kg.
Fire Hazard
(Non-Specific -- Organophosphorus Pesticide, n.o.s.). Container may explode in heat of fire. Fire and runoff from fire control water may produce irritating or poisonous gases. Storage above 113F, may lead to decomposition.
Trade name
Trade Names: APPA?; DECEMTHION?; DELPHOS
?; FESDAN?; FIREBAN?; FTALOPHOS?;
IMIDAN?; KEMOLATE?; PERCOLATE?; PMC?;
PROLATE?[C]; R 1504?; SAFIDON?; SMIDAN?;
STARBAR CATTLE DUST?[C]; STAUFFER R 1504?;
VET-KEM?; ZEOCON?
Safety Profile
A human poison by
ingestion. Poison experimentally by
inhalation and ingestion routes. Moderately
toxic by skin contact. Human systemic
effects by inhalation: lachqmation,
somnolence, and olfaction effects.
Experimental teratogenic and reproductive
effects. Mutation data reported. When
heated to decomposition it emits very toxic
fumes of NOx, POx, and SOx. See also
ESTERS.
Potential Exposure
An organophosphorus insecticide and acaricide.
Carcinogenicity
No treatment-related increases
in tumor incidence occurred in rats given a diet with 0, 20, 40,200, or 400 ppm (400 ppm terminated at 12 months) (equivalent
to 0, 1.1, 1.8, 9.4, and 23 mg/kg/day in males and 0, 1.1,
2.1, 10.9, and 27 mg/kg/day in females) for 2 years .
When mice were given diets with 0, 5, 25, or 100 ppm
phosmet (approximately 0.75, 3.75, or 15.0 mg/kg/day) for
2 years, there was an increased incidence of hepatocellular
tumors in males and mammary gland tumors in
females .
Environmental Fate
Soil. In soils, phosmet is rapidly hydrolyzed to phthalimide (Camazano and Martin,
1980; Sánchez Camazano and Sánchez Martin, 1983). The rate of hydrolysis is greater in
the presence of various montmorillonite clays and chloride salts. The calculated hydrolysis
half-lives of phosmet in the presence of calcium, barium, copper, magnesium and nickel
montmorillonite clays were 0.084, 0.665, 10.025, 16.926 and 28.738 days, respectively.
Similarly, the half-lives of phosmet in the presence of copper, calcium, magnesium and
barium chlorides were <0.020, 5.731, 10.680 and 12.242 days, respectively. In comparison,
the hydrolysis of phosmet in a neutral water solution was 46.210 days (Sánchez Camazano
and Sánchez Martin, 1983)Plant. In plants, phosmet is degraded to nontoxic compounds (Hartley and Kidd, 1987).
Dorough et al. (1966) reported the half-life in Bermuda grass was 6.5 days. Half-life values
ranged from 1.2 to 6.5 days (Dorough et al., 1966; Leuck and BowmanChemical/Physical. Emits toxic fumes of phosphorus, nitrogen and sulfur oxides when
heated to decomposition (Sax and Lewis, 1987). Though no products were identified, thehydrolysis half-lives at 20°C were 7.0 days and 7.1 hours at pH 6.1 and pH 7.4, respectively.
At 37.5°C and pH 7.4, the hydrolysis is 1.1 hours (Freed et al., 1979)
Metabolic pathway
The main degradative route of phosmet metabolism in plants and animals
is similar with the compound being hydrolysed via attack on the carbonyl
group of the phthaloyl moiety, yielding phthalamic acid which is further
hydrolysed and decarboxylated to benzoic acid. It should be noted,
however, that the studies on which the evidence for these metabolites
is based are old and used paper chromatography for the main
analytical evidence. A rather later study in rats identified N-hydroxymethylphthalimide
and phthalimide as metabolites, implying a degradative
hydrolytic route via attack on the N-methylene carbon atom.
Oxidative desulfuration to the active acetylcholinesterase inhibitor
phosmet oxon predominates over hydrolysis in insects and is responsible
for the selectivity of the compound.
Metabolism
Orally administered
phosmet in mammals is rapidly degraded to
phthalamic acid, phthalic acid, and phthalic acid derivatives,
and the metabolites are excreted in the urine.
Oxidative desulfuration to the oxon predominates over
hydrolysis in insects. It is rapidly degraded in plants
and soils.
Shipping
UN2783 Organophosphorus pesticides, solid, toxic, Hazard Class: 6.1; Labels: 6.1-Poisonous materials. UN3018 Organophosphorus pesticides, liquid, toxic, Hazard Class: 6.1; Labels: 6.1-Poisonous materials. UN2811 Toxic solids, organic, n.o.s., Hazard Class: 6.1; Labels: 6.1Poisonous materials, Technical Name Required.
Degradation
Phosmet is relatively stable in acid media but it is hydrolysed under basic
conditions. The half-lives at pH values 4.5, 7 and 8.3 were 13 days, <12
hours and <4 hours, respectively (PM). Phosmet was hydrolysed under
basic conditions to phthalamic acid (2), phthalic acid (3) and O,Odimethyl
phosphorodithioate (4) indicating that nucleophic attack by
OH-occurs preferentially on the phthalimido carbonyl group rather than
on phosphorus (Menn et al., 1965) (Scheme 1). The photolysis of an ether
solution of phosmet irradiated in a quartz tube by unfiltered UV light
from a mercury vapour lamp was investigated by Tanabe ef al. (1974).
Photoproducts were separated by silica gel column chromatography and
characterised by GLC, TLC, MS and 1H NMR spectroscopy in comparison
with authenticated reference standards. Two major photoproducts were
identified as N-methylphthalimide (5) and N-methoxymethylphthalimide
(6) (Scheme 1) in addition to a large number of minor products which
were not characterised. The use of a Pyrex filter to remove light below
286 nm reduced the rate of photolysis but not the nature of the products.
N-Methoxymethylphthalimide (6) was the main product when phosmet
was irradiated by sunlight in thin films on silica gel TLC plates or in dilute
aqueous solution [personal communication by McBain and Menn (1973),
in Tanabe et al., 1974].
Toxicity evaluation
The acute oral LD50 for rats is 113–160 mg/kg. Inhalation LC50
(1 h) for rats is 2.76 mg/L air. NOEL (2 yr) for rats
is 40 mg/kg/d. ADI is 0.01 mg/kg bw.
Incompatibilities
Organothiophosphates are susceptible to formation of highly toxic and flammable phosphine gas in the presence of strong reducing agents such as hydrideds and active metals. Partial oxidation by oxidizing agents may result in the release of toxic phosphorus oxides. Compounds of the carboxyl group react with all bases, both inorganic and organic (i.e., amines) releasing substantial heat, water and a salt that may be harmful. Incompatible with arsenic compounds (releases hydrogen cyanide gas), diazo compounds, dithiocarbamates, isocyanates, mercaptans, nitrides, and sulfides (releasing heat, toxic and possibly flammable gases), thiosulfates and dithionites (releasing hydrogen sulfate and oxides of sulfur). Not compatible with other pesticides under alkaline conditions. Contact with water, steam or moisture forms phthalic acids. Slightly corrosive to metals in the presence of moisture.
Waste Disposal
Consult with environmental regulatory agencies for guidance on acceptable disposal practices. Generators of waste containing this contaminant (≥100 kg/mo) must conform with EPA regulations governing storage, transportation, treatment, and waste disposal. 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. Small amounts may be decomposed with hypochlorite. For large amounts, incineration with effective gas scrubbing is recommended.
Check Digit Verification of cas no
The CAS Registry Mumber 732-11-6 includes 6 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 3 digits, 7,3 and 2 respectively; the second part has 2 digits, 1 and 1 respectively.
Calculate Digit Verification of CAS Registry Number 732-11:
(5*7)+(4*3)+(3*2)+(2*1)+(1*1)=56
56 % 10 = 6
So 732-11-6 is a valid CAS Registry Number.
InChI:InChI=1/C11H12NO4PS2/c1-15-17(18,16-2)19-7-12-10(13)8-5-3-4-6-9(8)11(12)14/h3-6H,7H2,1-2H3
732-11-6Relevant articles and documents
Macrocyclic plant acaricides
-
, (2008/06/13)
Compounds of the formula I STR1 in which either R is methyl and there is a double bond in the 9,10-position, or in which R is hydrogen and there is a single bond in the 9,10-position, are highly active against Acarina which damage plants.
