| Identification | More | [Name]
Phorate | [CAS]
298-02-2 | [Synonyms]
CEKUFORATOX
DHAN
EL-3911
KURUNAI
o,o-diethyl s-ethylmercaptomethyl dithiophosphate
O,O-DIETHYL S-[(ETHYLTHIO)METHYL] PHOSPHORODITHIOATE
PHORATE
Phosphorodithioic acid O,O-diethyl S-[(ethylthio)methyl] ester
THIMET
THIMET(R)
UMET
VOLPHOR
3911
Aastar
AC 3911
ac3911
ac8911
Agrimet
American Cyanamid 3,911
americancyanamid3,911 | [EINECS(EC#)]
206-052-2 | [Molecular Formula]
C7H17O2PS3 | [MDL Number]
MFCD00036348 | [Molecular Weight]
260.38 | [MOL File]
298-02-2.mol |
| Chemical Properties | Back Directory | [Appearance]
liquid | [Melting point ]
-43°C | [Boiling point ]
125-127°C (2 mmHg) | [density ]
d425 1.156 | [vapor pressure ]
8.5×10-2 Pa (25 °C) | [refractive index ]
nD25 1.5329 | [storage temp. ]
0-6°C | [form ]
neat | [Stability:]
Stable. Incompatible with strong oxidizing agents. | [Water Solubility ]
0.005 g/100 mL | [BRN ]
1708517 | [Exposure limits]
ACGIH TLV: TWA 0.05 mg/m3 ppm, STEL 0.2 mg/m3 | [CAS DataBase Reference]
298-02-2(CAS DataBase Reference) | [NIST Chemistry Reference]
Phorate(298-02-2) | [EPA Substance Registry System]
298-02-2(EPA Substance) |
| Safety Data | Back Directory | [Hazard Codes ]
T+;N,N,T+ | [Risk Statements ]
R27/28:Very Toxic in contact with skin and if swallowed .
R50/53:Very Toxic to aquatic organisms, may cause long-term adverse effects in the aquatic environment . | [Safety Statements ]
S28:After contact with skin, wash immediately with plenty of ... (to be specified by the manufacturer) .
S36/37:Wear suitable protective clothing and gloves .
S45:In case of accident or if you feel unwell, seek medical advice immediately (show label where possible) .
S60:This material and/or its container must be disposed of as hazardous waste .
S61:Avoid release to the environment. Refer to special instructions safety data sheet . | [RIDADR ]
UN 2810 | [WGK Germany ]
3 | [RTECS ]
TD9450000 | [HazardClass ]
6.1(a) | [PackingGroup ]
I | [Safety Profile]
Poison by ingestion and sh contact routes. Experimental reproductive effects. Mutation data reported. A cholinesterase irhbitor. When heated to decomposition it emits toxic fumes of POx and SOx. See also PARATHION | [Hazardous Substances Data]
298-02-2(Hazardous Substances Data) | [Toxicity]
LD50 in female, male rats (mg/kg): 1.1, 2.3 orally; 2.5, 6.2 dermally (Gaines) |
| Hazard Information | Back Directory | [General Description]
Clear liquid with an objectionable odor. Used as an insecticide and acaricide; PHORATE(298-02-2) is applied to plants and soil. | [Reactivity Profile]
Organothiophosphates, such as PHORATE, 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. | [Air & Water Reactions]
This compound is incompatible with the following: Water, alkalis [Note: Hydrolyzed in the presence of moisture and by alkalis.] . | [Health Hazard]
This material is one of the more toxic organophosphorus insecticides. It is a cholinesterase inhibitor that acts on the nervous system, and produces toxicity similar to Parathion. The probable oral lethal dose for humans is less than 5 mg/kg, i.e. a taste (less than 7 drops) for a 70 kg (150 lb.) person. | [Potential Exposure]
Those engaged in the manufacture, formulation and application of this systemic and contact insecticide and acaricide. It is also used as a soil insecticide. | [Fire Hazard]
Shock can shatter containers, releasing the contents. When heated to decomposition, toxic fumes of sulfur oxides, phosphorus oxides, and nitrogen oxides are emitted. Hydrolyzed in water and alkalies. | [First aid]
If this chemical gets into the eyes, remove any contact lenses at once and irrigate immediately for at least 15 minutes, occasionally lifting upper and lower lids. Seek medical attention immediately. If this chemical contacts the skin, remove contaminated clothing and wash immediately with soap and water. Speed in removing material from skin is of extreme importance. Seek medical attention immediately. If this chemical has been inhaled, remove from exposure, begin rescue breathing (using universal precautions, including resuscitation mask) if breathing has stopped and CPR if heart action has stopped. Transfer promptly to a medical facility. When this chemical has been swallowed, get medical attention. Give large quantities of water and induce vomiting. Do not make an unconscious person vomit. | [Shipping]
UN3018 Organophosphorus pesticides, liquid, toxic, Hazard Class: 6.1; Labels: 6.1-Poisonous materials. UN2783 Organophosphorus pesticides, solid, toxic, Hazard Class: 6.1; Labels: 6.1-Poisonous material. UN2810 Toxic liquids, organic, n.o.s., Hazard Class: 6.1; Labels: 6.1-Poisonous materials, Technical Name Required. | [Incompatibilities]
Water, alkalis. Hydrolyzed in the presence of moisture and by alkalis; may produce toxic oxides of phosphorus and sulfur. Strong oxidizers may cause release of toxic phosphorus oxides. Organophosphates, in the presence of strong reducing agents such as hydrides, may form highly toxic and flammable phosphine gas. Keep away from alkaline materials. | [Chemical Properties]
Phorate is a clear mobile liquid with a skunk-like odor | [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. 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. | [Uses]
Insecticide. | [Uses]
Phorate is a non-biocumulative organophosphate used as an insecticide and acaricide. Phorate is an inhibitor of acetylcholinesterase and pseudocholinesterase. | [Uses]
Phorate is a systemic insecticide used to control sucking and chewing
pests in a very wide range of crops. It is also active as a nematicide and
has some vapour phase activity. | [Uses]
Systemic insecticide for control of mites, chewing and sucking insects in fruits and
vegetables, cotton and some ornamentals | [Definition]
ChEBI: Phorate is an organic thiophosphate and an organothiophosphate insecticide. It has a role as an EC 3.1.1.7 (acetylcholinesterase) inhibitor, an EC 3.1.1.8 (cholinesterase) inhibitor, an acaricide and an agrochemical. It is functionally related to an (ethylsulfanyl)methanethiol. | [Agricultural Uses]
Insecticide, Acaricide, Nematicide: Phorate is an organophosphorus insecticide and
acaricide used to control a wide variety of sucking and
chewing insects, leafhoppers, leafminers, mites, somenematodes, and rootworms. It is used on many crops, including
root and field crops such as corn, cotton, coffee,
potatoes, sugar beets, beans, peanuts, wheat, some ornamental
and herbaceous plants, and bulb. In the U.S., 80%
of the annual use of phorate is applied to corn, potatoes
and cotton. It is available in granular and emulsifiable
concentrate formulations. Phorate has been shown to be
responsible for a large number of bird kills and it is extremely
toxic to mammals. Not approved for use in EU
countries. A U.S. EPA restricted Use Pesticide (RUP).
U.S. Maximum Allowable Residue Levels for Phorate (40
CFR 180.206): bean 0.1 ppm; beet, sugar, roots 0.3 ppm;
beet, sugar, tops 3 ppm; coffee, bean 0.02 ppm; corn, forage
0.5 ppm; corn, grain 0.1 ppm; corn, sweet, kernel plus
0.1 ppm; cob with husks removed ppm; cotton, undelinted
seed 0.05 ppm; hop 0.5 ppm; peanut 0.1 ppm; potato
0.5 ppm; sorghum, grain, grain 0.1 ppm; sorghum, grain,
stover 0.1 ppm; soybean 0.1 ppm; sugarcane, cane 0.1 ppm;
wheat, grain 0.05 ppm; wheat, hay 1.5 ppm; wheat, straw
0.05 ppm. | [Trade name]
AASTAR®[C]; AC 3911®; AGRIMET®;
AMERICAN CYANAMID 3,911®; EL 3911®;
EXPERIMENTAL INSECTICIDE 3911®; GEOMET®;
GRAMTOX®; GRANUTOX®; L 11/6®; METAPHOR®;
PHORATE-10G®; PHORIL®; RAMPART®;
TERRACLOR®; TERRATHION GRANULES®;
THIMENOX®; THIMET®; THEMET®; UMET®;
VEGFRU®; VERGFRU FORATOX® | [Carcinogenicity]
When dogs were given phorate
via capsules at doses of 0.005, 0.01, 0.05, or 0.25 mg/kg/day
for 1 year, slight body tremors, marginal inhibition of body
weight gain, and RBC and brain cholinesterase inhibition
occurred in males given 0.25 mg/kg/day .
No evidence of carcinogenicity occurred in rats given
diets that contained 0, 1, 3, or 6 ppm phorate (equal to about
0, 0.05, 0.15, or 0.3 mg/kg/day) for 2 years .
Erythrocyte and brain cholinesterase inhibition occurred at
exposures of 3 and 6 ppm. No evidence of carcinogenicity
or other adverse effects occurred in mice given diets that
contained 0, 1, 3, or 6 ppm phorate (equal to about 0, 0.15,
0.45, and 0.9 mg/kg/day) for 78 weeks, other than a slight
decrease in body weight gain in females that were fed
6 ppm . | [Environmental Fate]
Biological. [14C]Phorate degraded in a model ecosystem consisting of soil, plants and
water (Lichtenstein et al., 1974). Under both non-percolating and percolating water conditions, 12% of the applied amount migrated downward as the corresponding sulfone and
sulfoxide. Phorate was absorbed in the roots of corn and was transformed primarily to the
sulfone with trace amounts of the sulfoxide. Translocation of radioactive insecticide to
the leaves was also observed but the major products were identified as phoratoxon sulfone
and phoratoxon sulfoxide (Lichtenstein et al., 1974)
From the first-order biotic and abiotic rate constants of phorate in estuarine water and
sediment/water systems, the estimated biodegradation half-lives were 1.1–1.6 and 0.7–1.6
days, respectively (Walker et al., 1988)
Soil. The corresponding sulfoxide and sulfone and their phosphorothioate analogs are
major soil metabolites (Lichtenstein et al., 1974). The phosphorothioate analogs may
hydrolyze forming dithio-, thio- and orthophosphoric acids (Hartley and Kidd
Phorate was moderately persistent in soil. Way and Scopes (1968) reported residues
comprised 10% of applied dosage 540 days after application. The reported half-life in soil
is 82 days (Jury et al., 1987) and 68 days in a sandy soil (Way and Scopes, 1968). The
half-lives for phorate in soil incubated in the laboratory under aerobic conditions ranged
from 7 to 82.5 days with an average half-life of 75 days (Getzin and Chapman, 1960;
Getzin and Shark, 1970). Approximately three days after applying phorate to a sandy soil,
41% was lost to volatilization (Burns, 1971)
Plant. Oat plants were grown in two soils treated with [14C]phorate. Most of the
residues remained bound to the soil. Less than 2% of the applied [14C]phorate was
recovered from the oat leaves. The major residues in soil were phorate and the corr | [Metabolic pathway]
Phorate is metabolised by an analogous route to that of disulfoton. The
principal route of phorate metabolism in all media is activation via
oxidation of the thioether group to the sulfoxide (rapid) and sulfone
(slower). Thioether oxidation occurs preferentially to oxidative desulfuration
of the P=S group to the oxon, which is usually only present in
trace amounts, and there is good evidence that the sulfoxide and sulfone
oxons arise via phorate sulfoxide and sulfone rather than phorate oxon.
The more polar thiooxidised metabolites are translocated in plants and
are responsible for the compound’s systemic action. Of all phorate’s
metabolites, phorate oxon sulfone is the most active inhibitor of acetylcholinesterase
(Bowman and Casida, 1957). Degradative metabolism
occurs via oxidative dealkylation of the phosphorodithioate group or
hydrolysis of the oxon. | [Metabolism]
The metabolic routes of phorate are essentially the
same in plants, animals, and soils, involving the oxidation
of the sulfide group into the sulfoxide then sulfone,
and oxidative desulfuration to the corresponding
oxons, followed by hydrolysis to diethyl hydrogen phosphorodithioate,
phosphorothioate, and phosphate. Phorate
protects plants for a relatively long time because of the
persistency of the sulfoxide metabolite in plants and in
soils. DT50 in soil is 2–14 d. | [Degradation]
Phorate in aqueous solution is hydrolysed and degraded by light.
The half-lives at pH 7 and 9 were 3.2 and 3.9 days, respectively (PM).
When exposed to sunlight or UV light phorate was apparently oxidised
to products which were more active inhibitors of acetylcholinesterase
than phorate or its sulfoxide (Bowman and Casida, 1957). Although not
specifically identified these photolysis products were likely to be the
thiooxidised phorate oxon. |
| Questions And Answer | Back Directory | [Description]
Phorate is a kind of widely used organophosphate pesticide and acaricide1-2. It is a powerful pesticide effective against insects, mites, and nematodes3. It is a systemic insecticide that acts by inhibiting cholinesterases, enzymes involved in transmitting nerve impulses. However, it is very toxic both for target organisms and for mammals including human1-2. Because of its persistence in soil it is most useful in controlling soil-dwelling nematodes (microscopic roundworms that suck plant roots and transmit disease thereby). It is not recommended for use by the homeowner because it is extremely toxic and persistent3.
| [Sources]
- Mahajan, R, et al. "Phorate exposure and incidence of cancer in the agricultural health study. "Environmental Health Perspectives 114.8(2006):1205.
- https://en.wikipedia.org/wiki/Phorate
- https://www.britannica.com/science/phorate
|
|