959-98-8 Usage
Description
Endosulfan I, also known as Thiometon, is a colorless to brown crystalline compound with a mild odor similar to terpene or sulfur dioxide. It is a pesticide belonging to the organochlorine class and is known for its broad-spectrum insecticidal properties.
Uses
Used in Agriculture:
Endosulfan I is used as an insecticide for controlling a wide range of pests in various crops, including fruits, vegetables, cotton, and tea. It is effective against insects such as aphids, caterpillars, and mites, helping to protect crops from damage and increase yields.
Used in Public Health:
Endosulfan I is also used in public health applications for controlling disease-transmitting insects, such as mosquitoes and flies. Its residual action and effectiveness against various insect species make it a valuable tool in vector control programs aimed at reducing the spread of diseases like malaria and dengue fever.
However, it is important to note that the use of Endosulfan I has been restricted or banned in many countries due to its potential environmental and health risks, including its persistence in the environment, bioaccumulation in the food chain, and potential endocrine-disrupting effects. Alternative safer and more environmentally friendly insecticides are being developed and promoted for use in place of Endosulfan I.
Air & Water Reactions
Insoluble in water. Slowly hydrolyzes to form sulfur dioxide and diol; hydrolyzes more rapidly under basic or acidic conditions.
Reactivity Profile
Endosulfan I is an organochlorine, cyclodiene derivative. Also a sulfite ester. Incompatible with strong oxidizing and reducing agents. Also incompatible with many amines, nitrides, azo/diazo compounds, alkali metals, and epoxides. As an ester Endosulfan I will hydrolyze to form sulfur dioxide and a diol; reaction is more rapid under basic conditions.
Fire Hazard
Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes. Containers may explode when heated. Runoff may pollute waterways.
Environmental Fate
Soil. Metabolites of endosulfan identified in soils were endosulfandiol (1,4,5,6,7,7-
hexachlorobicyclo[2.2.1]hept-5-ene-2,3-dimethanol), endosulfan ether, endosulfan lactone
(4,5,6,7,8,8-hexachloro-1,3,3a,4,7,7a-hexahydro-4,7-methane-isobenzofuran-1-one) and
endosulfan sulfate (6,7,8,9,10,10-hexachloro-1,5,5a,6,9,9a-hexahydro-6,9-methano-2,3,4-
benzodioxathiepin-3,3-dioxide) (Martens, 1977; Dreher and Podratzki, 1988). These compounds,
including endosulfan ether, were also reported as metabolites identified in aquatic
systems (Day, 1991). Endosulfan sulfate was the major biodegradation product in soils
under aerobic, anaerobic and flooded conditions (Martens, 1977). In flooded soils, endolactone
was detected only once whereas endodiol and endohydroxy ether were identified in
all soils under these conditions. Under anaerobic conditions, endodiol formed in low
amounts in two soils (Martens, 1977).
Indigenous microorganisms obtained from a sandy loam degraded a-endosulfan to
endosulfandiol. This diol was converted to endosulfan a-hydroxy ether and trace amounts
of endosulfan ether and both were degraded to endosulfan lactone (Miles and Moy, 1979).
Using settled domestic wastewater inoculum, a-endosulfan (5 and 10 mg/L) did not
degrade after 28 days of incubation at 25°C (Tabak et al., 1981).
Plant. Endosulfan sulfate was formed when endosulfan was translocated from the
leaves to roots in both bean and sugar beet plants (Beard and Ware, 1969). In tobacco
leaves, a-endosulfan is hydrolyzed to endosulfandiol (Chopra and Mahfouz, 1977). Stewart
and Cairns (1974) reported the metabolite endosulfan sulfate was identified in potato peels
and pulp at concentrations of 0.3 and 0.03 ppm, respectively. They also reported that the
half-life for the conversion of a-endosulfan to b-endosulfan was 60 days. On apple leaves,
direct photolysis of endosulfan by sunlight yielded endosulfan sulfate (Harrison et al.,
1967).
In carnation plants, the half-lives of a-endosulfan stored under four different conditions,
non-washed and exposed to open air, washed and exposed to open air, non-washed
and placed in an enclosed container and under greenhouse conditions were 6.79, 6.38,
10.45 and 4.22 days, respectively (Céron et al., 1995).
Surface Water. Endosulfan sulfate was also identified as a metabolite in a survey of
11 agricultural watersheds located in southern Ontario, Canada (Frank et al., 1982). When
endosulfan (a- and b- isomers, 10 mg/L) was added to Little Miami River water, sealed
and exposed to sunlight and UV light for 1 week, a degradation yield of 70% was observed.
After 2 and 4 weeks, 95% and 100% of the applied amount degraded. The major degradation
product was identified as endosulfan alcohol by IR spectrometry (Eichelberger and
Lichtenberg, 1971).
Photolytic. Thin films of endosulfan on glass and irradiated by UV light (l >300 nm)
produced endosulfandiol with minor amounts of endosulfan ether, a lactone, an a-hydroxyether
and other unidentified compounds (Archer et al., 1972). When an aqueous solution
containing endosulfan was photooxidized by UV light at 90–95°C, 25, 50 and 75%
degraded to carbon dioxide after 5.0, 9.5 and 31.0 hours, respectively (Knoevenagel and
Himmelreich, 1976).
Chemical/Physical. Endosulfan slowly hydrolyzes forming endosulfandiol and
endosulfan sulfate (Kollig, 1993; Martens, 1976; Worthing and Hance, 1991). The hydrolysis
rate constant for a-endosulfan at pH 7 and 25°C was determined to be 3.2 ′ 10–3/hour,
resulting in a half-life of 9.0 days (Ellington et al., 1988). The hydrolysis half-lives are
reduced significantly at varying pHs and temperature. At temperatures (pH) of 87.0 (3.12),
68.0 (6.89) and 38.0°C (8.69), the half-lives were 4.3, 0.10 and 0.08 days, respectively
(Ellington et al., 1986). Greve and Wit (1971) reported the hydrolysis half-lives of a-
endosulfan at 20°C and pH values of 7 and 5.5 were 36 and 151 days, respectively.
Emits toxic fumes of chlorides and sulfur oxides when heated to decomposition (Lewis,
1990).
Check Digit Verification of cas no
The CAS Registry Mumber 959-98-8 includes 6 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 3 digits, 9,5 and 9 respectively; the second part has 2 digits, 9 and 8 respectively.
Calculate Digit Verification of CAS Registry Number 959-98:
(5*9)+(4*5)+(3*9)+(2*9)+(1*8)=118
118 % 10 = 8
So 959-98-8 is a valid CAS Registry Number.
InChI:InChI=1/C9H6Cl6O3S/c10-5-6(11)8(13)4-2-18-19(16)17-1-3(4)7(5,12)9(8,14)15/h3-4H,1-2H2/t3-,4+,7+,8-,19+
959-98-8Relevant articles and documents
Photoinduced Reactions: Part IV - Studies on Photochemical Fate of 6,7,8,9,10,10-Hexachloro-1,5,5a,6,9,9a-hexahydro-6,9-methano-2,4,3-benzodioxathiepin-3-oxide (Endosulphan), an Important Insecticide
Dureja, P.,Mukerjee, S. K.
, p. 411 - 413 (2007/10/02)
The photolysis of the cyclodiene insecticide endosulphan (6,7,8,9,10,10-hexachloro-1,5,5a,6,9,9a-hexahydro-6,9-methano-2,4,3-benzodioxathiepin-3-oxide) has been examined under different conditions, including environmental.Two new photometabolites, photo-α-endosulphan and photo-β-endosulphan have been isolated from α- and β-isomers of endosulphan respectively and characterised on the basis of their 13C NMR spectra and other data.Irradiation in polar solvents gives metabolites similar to those formed under biotic conditions.When exposed to sunlight on plant leaves, α-endosulphane not only forms the photometabolite but also undergoes isomerisation to β-isomer.On the other hand β-isomer is relatively more stable.This explains the relatively longer persistence of β-endosulphan in the environment and may have some significance on their toxicity.
