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Demeton (Ref: ENT 17295)
(Also known as: E 1059; mercaptophos)
SUMMARY
Demeton is an organophosphate insecticide. It has a high aqueous solubility and is highly volatile. There are considerable gaps in literature regarding its environmental fate. Demeton is highly toxic to mammals, is a neurotoxin and may also adversely affect reproduction and/or development. It is also an acetyl cholinesterase inhibitor. It is highly toxic to birds and aquatic invertebrates. It moderately toxic to fish and honeybees.
Data 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.

Environmental fate Ecotoxicity Human health
 
Ecotoxicity
High alert:
Birds acute ecotoxicity: High; Daphnia acute ecotoxicity: High
Human health
High alert:
Mammals acute toxicity: High; Reproduction/development effects; Acetyl cholinesterase inhibitor; Neurotoxicant
GENERAL INFORMATION
Description
An insecticide used to control sucking insects on a range of crops
Example pests controlled
Aphids; Sawflies; Spidermites; Thrips
Example applications
Fruit; Vegetables; Potatoes; Cereals; Ornamentals; Tree nuts
Efficacy & activity
-
Availability status
Considered obsolete but may be available in some countries
Introduction & key dates
-
UK regulatory status
UK COPR regulatory status
Not approved
Date COPR inclusion expires
Expired
UK LERAP status
No UK approval for use
EC Regulation 1107/2009 (repealing 91/414)
EC Regulation 1107/2009 status
Not approved
Dossier rapporteur/co-rapporteur
Not applicable
Date EC 1107/2009 inclusion expires
Expired
EU Candidate for substitution (CfS)
Not applicable
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
Demeton is a mixture of thiol and thiono isomers
Chemical formula
C₈H₁₉O₃PS₂
Canonical SMILES
CCOP(=S)(OCC)OCCSCC
Isomeric SMILES
No data
International Chemical Identifier key (InChIKey)
DGLIBALSRMUQDD-UHFFFAOYSA-N
International Chemical Identifier (InChI)
InChI=1S/2C8H19O3PS2/c1-4-10-12(9,11-5-2)14-8-7-13-6-3;1-4-9-12(13,10-5-2)11-7-8-14-6-3/h2*4-8H2,1-3H3
2D structure diagram/image available?
Yes
General status
Pesticide type
Insecticide, Acaricide
Substance groups
Organophosphate insecticide; Organothiophosphate insecticide; Organophosphate acaricide; Organothiophosphate acaricide
Minimum active substance purity
-
Known relevant impurities
-
Substance origin
Synthetic
Mode of action
Systemic with contact and stomach action. Acetylcholinesterase (AChE) inhibitor.
CAS RN
8065-48-3
EC number
620-378-6
CIPAC number
None allocated
US EPA chemical code
057601
PubChem CID
24722
CLP index number
No data found
Molecular mass
258.34
PIN (Preferred Identification Name)
reaction mixture of O,O-diethyl O-[2-(ethylsulfanyl)ethyl] phosphorothioate and O,O-diethyl S-[2-(ethylsulfanyl)ethyl] phosphorothioate
IUPAC name
reaction mixture of O,O-diethyl O-2-ethylthioethyl phosphorothioate and O,O-diethyl S-2-ethylthioethyl phosphorothioate
CAS name
O,O-diethyl O-(2-(ethylthio)ethyl) phosphorothioate mixture with O,O-diethyl S-(2-(ethylthio)ethyl) phosphorothioate
Other status information
-
Relevant Environmental Water Quality Standards
UK Statutory standard for the protection of aquatic life in inland, coastal and territorial waters: 0.5 µg l⁻¹ as annual average
Herbicide Resistance Classification (HRAC)
Not applicable
Herbicide Resistance Classification (WSSA)
Not applicable
Insecticide Resistance Classification (IRAC)
1B
Fungicide Resistance Classification (FRAC)
Not applicable
Examples of recorded resistance
Aphis fabae, Myzus persicae, Tetranychus urticae, Tetranychus viennensis, Aphis gossypii, Liriomyza trifolii, many others
Physical state
Bright yellow oil
Related substances & organisms
Formulations
Property
Value
Example manufacturers & suppliers of products using this active now or historically
  • Bayer
  • Mobay
Example products using this active
  • Demox
  • Systemox
  • Systox
Formulation and application details
Formulated as an emulsifiable concentrate.
ENVIRONMENTAL FATE
Property
Value
Source; quality score; and other information
Interpretation
Solubility - In water at 20 °C (mg l⁻¹)
666
V2 V = ChemID Online Databases; Chemspider; PubChem. (ChemID )
2 = Unverified data of unknown source
(varies significantly with isomer)		 High
Solubility - In organic solvents at 20 °C (mg l⁻¹)
- - -
Melting point (°C)
-25
E3 E = Manufacturers safety data sheets
3 = Unverified data of known source
 -
Boiling point (°C)
125
F4 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 )
4 = Verified data
 -
Degradation point (°C)
- - -
Flashpoint (°C)
- - -
Octanol-water partition coefficient at pH 7, 20 °C
P
1.62 X 1003 Calculated -
Log P
3.21
V3 V = ChemID Online Databases; Chemspider; PubChem. (ChemID )
3 = Unverified data of known source
 High
Fat solubility of residues
Solubility
- - -
Data type
- - -
Density (g ml⁻¹)
1.126
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
 -
Dissociation constant pKa) at 25 °C
- - -
-
Vapour pressure at 20 °C (mPa)
36.26
F4 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 )
4 = Verified data
 Highly volatile
Henry's law constant at 25 °C (Pa m³ mol⁻¹)
0.387 - Moderately volatile
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 on plant matrix
Value
7.8
R4 R = Peer reviewed scientific publications
4 = Verified data
 -
Note
Published literature RL₅₀ range 3.9-11.5 days, leaves of 6 field crops, n=5
Dissipation rate RL₅₀ on and in plant matrix
Value
11.7
R4 R = Peer reviewed scientific publications
4 = Verified data
 -
Note
Published literature RL₅₀ range 4.8-30.0 days, various matrices from of 6 field crops, n=6
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)
- - -
Soil adsorption and mobility
Property
Value
Source; quality score; and other information
Interpretation
Linear
Kd
- - -
Koc
-
Notes and range
-
Freundlich
Kf
- - -
Kfoc
-
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
- - -
Bio-concentration factor
BCF (l kg⁻¹)
- - -
CT₅₀ (days)
- -
Known metabolites

None
ECOTOXICOLOGY
Terrestrial ecotoxicology
Property
Value
Source; quality score; and other information
Interpretation
Mammals - Acute oral LD₅₀ (mg kg⁻¹)
2.5
F4 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 )
4 = Verified data
Rat		 High
Mammals - Short term dietary NOEL
(mg kg⁻¹)
- - -
(ppm diet)
- -
Mammals - Chronic 21d NOAEL (mg kg⁻¹ bw d⁻¹)
- - -
Birds - Acute LD₅₀ (mg kg⁻¹)
7.18
F4 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 )
4 = Verified data
Anas platyrhynchos		 High
Birds - Short term dietary (LC₅₀/LD₅₀)
- - -
Birds - Chronic 21d NOEL (mg kg⁻¹ bw d⁻¹)
- - -
Earthworms - Acute 14 day LC₅₀ (mg kg⁻¹)
- - -
Earthworms - Chronic NOEC, reproduction (mg kg⁻¹)
- - -
Soil micro-organisms
- - -
Collembola
Acute LC₅₀ (mg kg⁻¹)
- - -
Chronic NOEC (mg kg⁻¹)
- - -
Non-target plants
- - -
- - -
Honeybees (Apis spp.)
Contact acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)
- - -
Oral acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)
- - -
Unknown mode acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)
> 2.6
F4 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 )
4 = Verified data
 Moderate
Chronic
- - -
Bumblebees (Bombus spp.)
Contact acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)
> 1.0
R4 R = Peer reviewed scientific publications
4 = Verified data
Bombus lucorum 24 hr		 Moderate
-
Oral acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)
- - -
-
Mason bees (Osmia spp.)
Contact acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)
- - -
Oral acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)
- - -
Other bee species (1)
Acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg insect⁻¹)
0.076
R4 R = Peer reviewed scientific publications
4 = Verified data
Megachile rotundata		 High
Mode of exposure
Contact
Other bee species (2)
Acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg insect⁻¹)
0.026
R4 R = Peer reviewed scientific publications
4 = Verified data
Nomia melanderi		 High
Mode of exposure
Contact
Beneficial insects (Ladybirds)
- - -
Beneficial insects (Lacewings)
- - -
Beneficial insects (Parasitic wasps)
- - -
Beneficial insects (Predatory mites)
- - -
Beneficial insects (Ground beetles)
- - -
Aquatic ecotoxicology
Property
Value
Source; quality score; and other information
Interpretation
Fish - Acute 96 hour LC₅₀ (mg l⁻¹)
1.6
F4 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 )
4 = Verified data
Oncorhynchus mykiss		 Moderate
Fish - Chronic 21 day NOEC (mg l⁻¹)
- - -
Aquatic invertebrates - Acute 48 hour EC₅₀ (mg l⁻¹)
0.0104
F4 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 )
4 = Verified data
Daphnia pulex		 High
Aquatic invertebrates - Chronic 21 day NOEC (mg l⁻¹)
- - -
Aquatic crustaceans - Acute 96 hour LC₅₀ (mg l⁻¹)
- - -
Sediment dwelling organisms - Acute 96 hour LC₅₀ (mg l⁻¹)
- - -
Sediment dwelling organisms - Chronic 28 day NOEC, static, water (mg l⁻¹)
- - -
Sediment dwelling organisms - Chronic 28 day NOEC, sediment (mg kg⁻¹)
- - -
Aquatic plants - Acute 7 day EC₅₀, biomass (mg l⁻¹)
- - -
Algae - Acute 72 hour EC₅₀, growth (mg l⁻¹)
- - -
Algae - Chronic 96 hour NOEC, growth (mg l⁻¹)
- - -
Mesocosm study data
NOEAEC mg l⁻¹
- - -
NOEAEC mg l⁻¹
- - -
HUMAN HEALTH AND PROTECTION
General
Property
Value
Source; quality score; and other information
Interpretation
Threshold of Toxicological Concern (Cramer Class)
High (class III) - -
Mammals - Acute oral LD₅₀ (mg kg⁻¹)
2.5
F4 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 )
4 = Verified data
Rat		 High
Mammals - Dermal LD₅₀ (mg kg⁻¹ body weight)
8.2
F4 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 )
4 = Verified data
Rat		 -
Mammals - Inhalation LC₅₀ (mg l⁻¹)
- - -
Other Mammal toxicity endpoints
- - -
ADI - Acceptable Daily Intake (mg kg⁻¹ bw day⁻¹)
- - -
ARfD - Acute Reference Dose (mg kg⁻¹ bw day⁻¹)
- - -
AAOEL - Acute Acceptable Operator Exposure Level (mg kg⁻¹ bw day⁻¹)
- - -
AOEL - Acceptable Operator Exposure Level - Systemic (mg kg⁻¹ bw day⁻¹)
- - -
Dermal penetration studies (%)
- - -
Dangerous Substances Directive 76/464
- - -
Exposure Routes
Public
-
Occupational
May be absorbed from the gastrointestinal tract, skin, and by inhalation
MRLs
European
EU MRL pesticide database 
Great Britain
GB MRL Register 
Notes
-
Drinking Water Standards
- - -
Drinking Water MAC (μg l⁻¹)
- - -
Mammalian dose elimination route and rate
- - -
Health issues
Specific human health issues
Carcinogen
Genotoxic
Endocrine disruptor
No data found
A0 A = Chromosome aberration (EFSA database)
0 = No data
;
B0 B = DNA damage/repair (EFSA database)
0 = No data
;
C0 C = Gene mutation (EFSA database)
0 = No data
;
D0 D = Genome mutation (EFSA database)
0 = No data
;
E0 E = Unspecified genotoxicity type (miscellaneous data source)
0 = No data
XNo, known not to cause a problem
Reproduction / development effects Acetyl cholinesterase inhibitor Neurotoxicant
✓Yes, known to cause a problem
✓Yes, known to cause a problem
✓Yes, known to cause a problem
Respiratory tract irritant Skin irritant Skin sensitiser
No data found No data found No data found
Eye irritant Phototoxicant  
No data found No data found  
General human health issues
No further information available
Handling issues
Property
Value and interpretation
General
No information available
CLP classification 2013
-
WHO Classification
Not classified: Obsolete
UN Number
-
Waste disposal & packaging
-
Shelf-life, storage, stability and reactivity
-
TRANSLATIONS
Language
Name
English
demeton
French
demeton
German
Demeton
Danish
demeton
Italian
demeton
Spanish
demeton
Greek
demeton
Polish
demeton
Swedish
demeton
Hungarian
demeton
Dutch
demeton
Norwegian
-
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