| demeton-S-methyl |
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SUMMARY
Demeton-S-methyl is an insecticide not approved for use in the EU. It is highly soluble in water, volatile and, based on its physico-chemical data, it is not expected to leach to groundwater. It is not persistent in soil systems. Demeton-S-methyl is highly toxic to mammals, a cholinesterase inhibitor, a neurotoxin and a recognised irritant. It is highly toxic to birds, aquatic invertebrates and honey bees and moderately toxic to most other species including fish and earthworms. GENERAL INFORMATION 
for demeton-S-methyl
Description: An insecticide used to control aphids and other sucking insects on a range of crops
Example pests controlled: Aphids including woolly aphids, citrus aphids, Russian aphids; Sawflies; Bryobia mites; Lacebugs
Example applications: Vegetables including beans, peas, brassicas, peppers, aubergines, onions; Fruit including olives, peaches, plums, apricots; Tomatoes; Cotton; Peanuts; Wheat; Maize; Sorghum
Efficacy & activity: -
Availability status: Unknown
Introduction & key dates: 1957
EC Regulation 1107/2009 (repealing 91/414):
| Status | Not approved |
| Dossier rapporteur/co-rapporteur | Not applicable |
| Date inclusion expires | Expired |
| EU Candidate for substitution (CfS) | Not applicable |
| Listed in EU database | Yes |
Approved for use (
) or known to be used (
) in the following European countries: 
AT |
BE |
BG |
CY |
CZ |
DE |
DK |
EE |
EL |
ES |
FI |
FR |
HR |
HU |
IE |
IT |
LT |
LU |
LV |
MT |
NL |
PL |
PT |
RO |
SE |
SI |
SK |
UK |
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Chemical structure:
| Isomerism | The methyl ester of the S-form of isomeric demeton |
| Chemical formula | C6H15O3PS2 |
| Canonical SMILES | CCSCCSP(=O)(OC)OC |
| Isomeric SMILES | No data |
| International Chemical Identifier key (InChIKey) | WEBQKRLKWNIYKK-UHFFFAOYSA-N |
| International Chemical Identifier (InChI) | InChI=1S/C6H15O3PS2/c1-4-11-5-6-12-10(7,8-2)9-3/h4-6H2,1-3H3 |
| 2D structure diagram/image available? | Yes |
General status:
| Pesticide type | Insecticide, Acaricide | |||
| Substance group | Organophosphate | |||
| Minimum active substance purity | - | |||
| Known relevant impurities | - | |||
| Substance origin | Synthetic | |||
| Mode of action | Systemic with contact and stomach action. Acetylcholinesterase (AChE) inhibitor. | |||
| CAS RN | 919-86-8 | |||
| EC number | 213-052-6 | |||
| CIPAC number | 47 | |||
| US EPA chemical code | - | |||
| PubChem CID | 13526 | |||
| Molecular mass (g mol-1) | 230.29 | |||
| PIN (Preferred Identification Name) | S-[2-(ethylsulfanyl)ethyl] O,O-dimethyl phosphorothioate | |||
| IUPAC name | S-2-ethylthioethyl O,O-dimethyl phosphorothioate | |||
| CAS name | S-(2-(ethylthio)ethyl) O,O-dimethyl phosphorothioate | |||
| Other status information | Pan Bad Actor | |||
| Relevant Environmental Water Quality Standards | - | |||
| 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 gossypii Panonychus ulmi Tetranychus urticae Tetranychus viennensis Aculus cornutus Aphis craccivora many others |
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| Physical state | Yellow oil | |||
| Related substances & organisms | - | |||
Formulations:
| Property |
Value | |||
| Example manufacturers & suppliers of products using this active now or historically |
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| Example products using this active |
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| UK LERAP status | No UK approval for use as a pesticide under EC Regulation 1107/2009 | |||
| Formulation and application details | Usually supplied as an emulsifiable concentrate. | |||
ENVIRONMENTAL FATE
for demeton-S-methyl
| Property |
Value | Source/Quality Score/Other Information |
Interpretation |
|
| Solubility - In water at 20oC (mg l-1) | 22000 | L3 | High | |
| Solubility - In organic solvents at 20oC (mg l-1) | - | - | - | |
| Melting point (oC) | - | - | - | |
| Boiling point (oC) | - | - | - | |
| Degradation point (oC) | - | - | - | |
| Flashpoint (oC) | - | - | - | |
| Octanol-water partition coefficient at pH 7, 20oC | P | 2.09 X 1001 | Calculated | - |
| Log P | 1.32 | G4 | Low | |
| Bulk density (g ml-1)/Specific gravity | 1.21 | L3 | - | |
| Dissociation constant (pKa) at 25oC | - | - | - | |
| Note: | ||||
| Vapour pressure at 20oC (mPa) | 40 | L3 | Highly volatile | |
| Henry's law constant at 25oC (Pa m3 mol-1) | 4.19 X 10-04 | L3 | Non-volatile | |
GUS leaching potential index  |
0.88 | Calculated | Low leachability | |
| SCI-GROW groundwater index (μg l-1) for a 1 kg ha-1 or 1 l ha-1 application rate |
Value | 1.95 X 10-03 | Calculated | - |
| Note | - | |||
| Potential for particle bound transport index |
- | Calculated | Low | |
| Maximum UV-vis absorption L mol-1 cm-1 | - | - | - | |
| Surface tension (mN m-1) | - | - | - | |
Degradation:
| Property |
Value | Source/Quality Score/Other Information |
Interpretation |
General biodegradability | - |
| Soil degradation (days) (aerobic) | DT50 (typical) | 2.7 | K4 | Non-persistent |
| DT50 (lab at 20oC) | 2.7 | K4 | Non-persistent | |
| DT50 (field) | - | - | - | |
| DT90 (lab at 20oC) | - | - | - | |
| DT90 (field) | - | - | - | |
| DT50 modelling endpoint | - | - | - | |
| Note: | - | |||
| Dissipation rate RL50 on plant matrix | Value | - | - | - |
| Note | - | |||
| Dissipation rate RL50 on and in plant matrix | Value | 3.0 | R3 | - |
| Note | Mango fruit, n=1 | |||
| Aqueous photolysis DT50 (days) at pH 7 | Value | - | - | - |
| Note | - | |||
| Aqueous hydrolysis DT50 (days) at 20oC and pH 7 | Value | 56 | L3 | Moderately persistent |
| Note | pH sensitive: DT50 63 days at pH 4, 8 days at pH 9 all at 22 degC | |||
| Water-sediment DT50 (days) | - | - | - | |
| Water phase only DT50 (days) | - | - | - | |
Soil adsorption and mobility:
| Property |
Value | Source/Quality Score/Other Information |
Interpretation |
|
| Linear | Kd | - | W3 | Moderately mobile |
| Koc | 90 | |||
| Notes and range | - | |||
| Freundlich | Kf | - | - | - |
| Kfoc | - | |||
| 1/n | - | |||
| Notes and range | - | |||
| pH sensitivity | - | |||
Key metabolites:
| Metabolite | Formation medium | Estimated maximum occurrence fraction | 1107/2009 relevancy |
|
| demeton-S-methyl sulfone | Animal | - | - | |
ECOTOXICOLOGY
for demeton-S-methyl
| Property |
Value | Source/Quality Score/Other Information |
Interpretation |
|
| Bio-concentration factor | BCF (l kg-1) | 0.5 | R3 (LogP < 3) | Low potential |
| CT50 (days) | Not available | - | ||
| Mammals - Acute oral LD50 (mg kg-1) | 40 | F4 Rat | High | |
| Mammals - Short term dietary NOEL | (mg kg-1) | - | L2 Rat, 2 year | - |
| (ppm diet) | 1 | - | ||
| Birds - Acute LD50 (mg kg-1) | 44 | L3 Coturnix japonica | High | |
| Birds - Short term dietary (LC50/LD50) | - | - | - | |
| Fish - Acute 96 hour LC50 (mg l-1) | > 6.4 | L3 Oncorhynchus mykiss | Moderate | |
| Fish - Chronic 21 day NOEC (mg l-1) | - | - | - | |
| Aquatic invertebrates - Acute 48 hour EC50 (mg l-1) | > 0.023 | L3 Daphnia magna | 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) | - | - | - | |
| Non-target plants | - | - | - | |
| - | - | - | ||
| Algae - Acute 72 hour EC50, growth (mg l-1) | 22.1 | L3 Scenedemus subspicatus | Low | |
| Algae - Chronic 96 hour NOEC, growth (mg l-1) | 10 | Q2 Unknown species | Low | |
| Honeybees (Apis spp.) | Contact acute LD50 (worst case from 24 , 48 and 72 hour values - μg bee-1) | 2.6 | F3 Apis mellifera, 24hr | Moderate |
| Oral acute LD50 (worst case from 24 , 48 and 72 hour values - μg bee-1) | > 0.19 | K4 Apis mellifera | High | |
| Unknown mode acute LD50 (worst case from 24 , 48 and 72 hour values - μg bee-1) | - | - | - | |
| Bumblebees (Bombus spp.) | Contact acute LD50 (worst case from 24 , 48 and 72 hour values - μg bee-1) | > 2.68 | R4 Bombus terrestris, 48 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 pollinators (1) | Acute LD50 (worst case from 24 , 48 and 72 hour values - μg insect-1) | 0.076 | R4 Megachile rotundata | High |
| Mode of exposure | Contact | |||
| Other pollinators (2) | Acute LD50 (worst case from 24 , 48 and 72 hour values - μg insect-1) | - | - | - |
| Mode of exposure | - | |||
| Earthworms - Acute 14 day LC50 (mg kg-1) | > 250 | L3 Eisenia foetida | Moderate | |
| Earthworms - Chronic NOEC, reproduction (mg kg-1) | - | - | - | |
| Other soil macro-organisms | Acute LC50 (mg kg-1) | - | - | - | Chronic NOEC (mg kg-1) | - | - | - |
| Other arthropod (1) | LR50 g ha-1 | - | - | - |
| % Effect | Harmless | AB1 Typhlodromus pyri | - | |
| Other arthropod (2) | LR50 g ha-1 | - | - | - |
| % Effect | - | - | - | |
| Soil micro-organisms | - | - | - | |
| Mesocosm study data | NOEAEC mg l-1 | - | - | - |
| NOEAEC mg l-1 | - | - | - | |
HUMAN HEALTH AND PROTECTION
for demeton-S-methyl
General:
| Property |
Value | Source/Quality Score/Other Information |
Interpretation |
|
| Threshold of Toxicological Concern (Cramer Class) |
High (class III) | - | - | |
| Mammals - Acute oral LD50 (mg kg-1) | 40 | F4 Rat | High | |
| Mammals - Dermal LD50 (mg kg-1 body weight) | 30 | L3 Rat | - | |
| Mammals - Inhalation LC50 (mg l-1) | 0.13 | L3 Rat, (aerosol) | - | |
| Other Mammal toxicity endpoints | - | - | ||
| ADI - Acceptable Daily Intake (mg kg-1bw day-1) | 0.0003 | L3 | - | |
| ARfD - Acute Reference Dose (mg kg-1bw day-1) | - | - | - | |
| AAOEL - Acute Acceptable Operator Exposure Level (mg kg-1 bw day-1) | - | - | - | |
| AOEL - Acceptable Operator Exposure Level - Systemic (mg kg-1bw day-1) | - | - | - | |
| Dermal penetration studies (%) | - | - | - | |
| Dangerous Substances Directive 76/464 | List I; List II | - | - | |
| Exposure Routes | Public | - | ||
| Occupational | - | |||
| European MRLs | Click here for the EU MRL pesticide database | |||
| Drinking Water Standards | - | - | - | |
| Drinking Water MAC (μg l-1) | - | - | - | |
Health issues:
| Carcinogen | Genotoxic | Endocrine disrupter | Reproduction / development effects | Cholinesterase inhibitor | Neurotoxicant | |||
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A3; B0; C0; D0; E1 |
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| Respiratory tract irritant | Skin irritant | Skin sensitiser | Eye irritant | Phototoxicant | ||||
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| General human health issues | No further information available | |||||||
| Key: Genotoxicity A: Chromosome aberration (EFSA database) B: DNA damage/repair (EFSA database) C: Gene mutation (EFSA database) D: Genome mutation (EFSA database) E: Unspecified genotoxicity type (miscellaneous data source) 0: No data 1: Positive 2: Mixed/ambiguous results 3: Negative |
Key: Other : Yes, known to cause a problem  : No, known not to cause a problem  : Possibly, status not identified - : No data found |
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Handling issues:
| Property |
Value | Source/Quality Score/Other Information |
Interpretation |
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| General |
Combustible | |||
| CLP classification 2013 | Health: H301, H311 Environment: H411 |
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| EC Risk Classification |
T - Toxic: R24/25 N - Dangerous for the environment: R51, R53 |
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| EC Safety Classification |
S1/2, S28, S36/37, S45, S61 | |||
| WHO Classification | Ib | - | Highly hazardous | |
| UN Number | Usually 3018 | |||
| Waste disposal & packaging |
- | |||
TRANSLATIONS
for demeton-S-methyl
| Language | Name |
| English | demeton-S-methyl |
| French | demeton-S-methyle |
| German | Demeton-S-methyl |
| Danish | demeton-S-methyl |
| Italian | demeton-s-metil |
| Spanish | demeton-S-metil |
| Greek | demeton-S-methyl |
| Slovenian | demeton-S-metil |
| Polish | demeton-S-metylowy |
| Swedish | - |
| Hungarian | - |
| Dutch | demeton-S-methyl |
Record last updated: Tuesday 26 November 2019
Contact: aeru@herts.ac.uk