(Also known as: ethylthiometon sulfoxide ; oxydisulfoton)
SUMMARY
Hazard alerts
The following alerts are based on the data in the tables below. An absence of an alert does not imply the substance has no implications for human health, biodiversity or the environment but just that we do not have the data to form a judgement. These hazard alerts do not take account of usage patterns or exposure, thus do not represent risk.
Environmental fate
Ecotoxicity
Human health
Environmental fate Moderate alert: Drainflow: Moderately mobile
Warning: Significant data are missing
Ecotoxicity High alert: Daphnia acute ecotoxicity: High
Warning: Significant data are missing
Human health High alert: Mammals acute toxicity: High; Acetyl cholinesterase inhibitor; Neurotoxicant
GENERAL INFORMATION
Description
A largely obsolete insecticide that was used to control sucking and chewing pests. It may also be a chemical transformation product
No UK approval for use as a plant protection agent
EC Regulation 1107/2009 (repealing 91/414)
EC Regulation 1107/2009 status
Not applicable
Dossier rapporteur/co-rapporteur
Not applicable
Date EC 1107/2009 inclusion expires
Not applicable
EU Candidate for substitution (CfS)
Not approved
Listed in EU database
No
Approved for use (✓) under EC 1107/2009 in the following EU Member States
ATAustria
BEBelgium
BGBulgaria
CYCyprus
CZCzech Republic
DEGermany
DKDenmark
EEEstonia
ELGreece
ESSpain
FIFinland
FRFrance
HRCroatia
HUHungary
IEIreland
ITItaly
LTLithuania
LULuxembourg
LVLatvia
MTMalta
NLNetherlands
PLPoland
PTPortugal
RORomania
SESweden
SISlovenia
SKSlovakia
Approved for use (✓) under EC 1107/2009 by Mutual Recognition of Authorisation and/or national regulations in the following EEA countries
ISIceland
NONorway
Additional information
Also used in
-
Chemical structure
Isomerism
Disulfoton sulfoxide exhibits stereoisomerism due to the presence of a sulfoxide functional group (S=O), which introduces a chiral sulphur centre. Unlike carbon-based chirality, sulphur in sulphoxides can become stereogenic when bonded to two different substituents and an oxygen atom. In disulfoton sulfoxide, the sulphur atom is bonded to an ethyl group, a thioether-linked alkyl chain, and a double-bonded oxygen, creating a non-superimposable mirror image, i.e., R- and S-enantiomers. Commercial formulations typically contain a racemic mixture.
Considered obsolete but may be available in some countries
Introduction & key dates
1998, first registered USA; 2009, cancelled USA
Example manufacturers & suppliers of products using this active now or historically
Bayer CropScience
Example products using this active
Disyston S
Formulation and application details
-
Commercial production
The production of disulfoton sulfoxide typically begins with disulfoton, its parent compound. The sulfoxide derivative is synthesised through a controlled oxidation process, where disulfoton is treated with dihydrogen peroxide in the presence of a vanadium-based catalyst, often vanadia, in a solvent like tert-butyl alcohol. This reaction selectively oxidises one of the sulphur atoms to a sulfoxide without over-oxidising to the sulfone. The product is then isolated and purified, usually by solvent extraction and crystallisation, yielding disulfoton sulfoxide with high efficiency.
Impact on climate of production and use
Data for the amount of life cycle GHGs produced by disulfoton sulfoxide are not available in the public domain. However, whilst estimates vary, more general data suggests that between 14 and 19 kilograms of CO₂e is emitted per kilogram of insecticide produced.
ENVIRONMENTAL FATE
Property
Value
Source; quality score; and other information
Interpretation
Solubility - In water at 20 °C (mg l⁻¹)
4000
V3 V = ChemID Online Databases; Chemspider; PubChem. (ChemID ) 3 = Unverified data of known source
High
Solubility - In organic solvents at 20 °C (mg l⁻¹)
-
-
-
Melting point (°C)
-
-
-
Boiling point (°C)
-
-
-
Degradation point (°C)
-
-
-
Flashpoint (°C)
-
-
-
Octanol-water partition coefficient at pH 7, 20 °C
P
5.37 X 1001
Calculated
-
Log P
1.73
V3 V = ChemID Online Databases; Chemspider; PubChem. (ChemID ) 3 = Unverified data of known source
Low
Fat solubility of residues
Solubility
-
-
-
Data type
-
-
-
Density (g ml⁻¹)
1.27
Q2 Q = Miscellaneous data from online sources 2 = Unverified data of unknown source
-
Dissociation constant pKa) at 25 °C
-
-
-
-
Vapour pressure at 20 °C (mPa)
-
-
-
Henry's law constant at 25 °C (Pa m³ mol⁻¹)
-
-
-
Volatilisation as max % of applied dose lost
From plant surface
-
-
-
From soil surface
-
-
-
Maximum UV-vis absorption L mol⁻¹ cm⁻¹
-
-
-
Surface tension (mN m⁻¹)
-
-
-
Degradation
Property
Value
Source; quality score; and other information
Interpretation
General biodegradability
-
Soil degradation (days) (aerobic)
DT₅₀ (typical)
-
-
-
DT₅₀ (lab at 20 °C)
-
-
-
DT₅₀ (field)
-
-
-
DT₉₀ (lab at 20 °C)
-
-
-
DT₉₀ (field)
-
-
-
DT₅₀ modelling endpoint
-
-
-
Note
-
Dissipation rate RL₅₀ (days) on plant matrix
Value
-
-
-
Note
-
Dissipation rate RL₅₀ (days) on and in plant matrix
Value
-
-
-
Note
-
Aqueous photolysis DT₅₀ (days) at pH 7
Value
-
-
-
Note
-
Aqueous hydrolysis DT₅₀ (days) at 20 °C and pH 7
Value
-
-
-
Note
-
Water-sediment DT₅₀ (days)
-
-
-
Water phase only DT₅₀ (days)
-
-
-
Sediment phase only DT₅₀ (days)
-
-
-
Air degradation
As this parameter is not normally measured directly, a surrogate measure is used: ‘Photochemical oxidative DT₅₀’. Where data is available, this can be found in the Fate Indices section below.
Decay in stored produce DT₅₀
-
Soil adsorption and mobility
Property
Value
Source; quality score; and other information
Interpretation
Linear
Kd (mL g⁻¹)
-
Q2 Q = Miscellaneous data from online sources 2 = Unverified data of unknown source
Moderately mobile
Koc (mL g⁻¹)
208
Notes and range
Estimated
Freundlich
Kf (mL g⁻¹)
-
-
-
Kfoc (mL g⁻¹)
-
1/n
-
Notes and range
-
pH sensitivity
-
Fate indices
Property
Value
Source; quality score; and other information
Interpretation
GUS leaching potential index
-
-
-
SCI-GROW groundwater index (μg l⁻¹) for a 1 kg ha⁻¹ or 1 l ha⁻¹ application rate
Value
Cannot be calculated
-
-
Note
-
Potential for particle bound transport index
-
-
-
Potential for loss via drain flow
Moderately mobile
Calculated
-
Photochemical oxidative DT₅₀ (hrs) as indicator of long-range air transport risk
-
-
-
Bio-concentration factor
BCF (l kg⁻¹)
1
R3 R = Peer reviewed scientific publications 3 = Unverified data of known source
F3 F = U.S. EPA ECOTOX database / U.S. EPA pesticide fate database / Miscellaneous WHO documents / FAO data, IPCS INCHEM data (US EPA Databases Related to Pesticide Risk Assessment ) 3 = Unverified data of known source
Lewis, K.A., Tzilivakis, J., Warner, D. and Green, A. (2016) An international database for pesticide risk assessments and management. Human and Ecological Risk Assessment: An International Journal, 22(4), 1050-1064. DOI: 10.1080/10807039.2015.1133242
Environmental fate
Warning:
Ecotoxicity
