| MCPA-thioethyl |
 |
Environmental Fate - Ecotoxicology - Human Health - A to Z Index - Home
GENERAL INFORMATION 
for MCPA-thioethyl
Description: A herbicide for control of annual and perennial broad-leaved weeds.
Example pests controlled: Annual and perennial broad-leaved weeds including Charlock, Wild radish, Dandylion, Capeweed, Fat hen and Hedge mustards
Example applications: Wheat; Oats; Tritical; Rye; Establish gras
Efficacy & activity: -
Availability status: Current
Introduction & key dates: 1973
EC Regulation 1107/2009 (repealing 91/414):
| Status | Approved |
| Dossier rapporteur/co-rapporteur | Poland/Netherlands |
| Date inclusion expires | 31/10/2020 |
| EU Candidate for substitution (CfS) | No |
| 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 | - |
| Chemical formula | C11H13ClO2S |
| Canonical SMILES | CCSC(=O)COC1=C(C=C(C=C1)Cl)C |
| Isomeric SMILES | No data |
| International Chemical Identifier key (InChIKey) | AZFKQCNGMSSWDS-UHFFFAOYSA-N |
| International Chemical Identifier (InChI) | InChI=1S/C11H13ClO2S/c1-3-15-11(13)7-14-10-5-4-9(12)6-8(10)2/h4-6H,3,7H2,1-2H3 |
| 2D structure diagram/image available? | Yes |
Cambridge Crystallographic Data Centre diagrams:
| Common Name | Relationship | Link |
| MCPA | Derivative |  |
General status:
| Pesticide type | Herbicide | |||
| Substance group | Aryloxyalkanoic acid | |||
| Minimum active substance purity | 920 g/kg | |||
| Known relevant impurities | EU dossier - None declared | |||
| Substance origin | Synthetic | |||
| Mode of action | Selective, systemic with translocation. Synthetic auxin. | |||
| CAS RN | 25319-90-8 | |||
| EC number | 246-831-4 | |||
| CIPAC number | 8205 | |||
| US EPA chemical code | 431500 | |||
| PubChem CID | 32876 | |||
| Molecular mass (g mol-1) | 244.74 | |||
| PIN (Preferred Identification Name) | S-ethyl (4-chloro-2-methylphenoxy)ethanethioate | |||
| IUPAC name | S-ethyl 4-chloro-o-tolyloxythioacetate | |||
| CAS name | S-ethyl (4-chloro-2-methylphenoxy)ethanethioate | |||
| Other status information | - | |||
| Relevant Environmental Water Quality Standards | - | |||
| Herbicide Resistance Classification (HRAC) | O | |||
| Herbicide Resistance Classification (WSSA) | 4 | |||
| Insecticide Resistance Classification (IRAC) | Not applicable | |||
| Fungicide Resistance Classification (FRAC) | Not applicable | |||
| Examples of recorded resistance | - | |||
| Physical state | Solid | |||
| Related substances & organisms | - | |||
Formulations:
| Property |
Value | |||
| Example manufacturers & suppliers of products using this active now or historically | - | |||
| Example products using this active | - | |||
| UK LERAP status | None | |||
| Formulation and application details | Often supplied as soluble concentrate that is mixed with water and used as a spray. | |||
ENVIRONMENTAL FATE
for MCPA-thioethyl
| Property |
Value | Source/Quality Score/Other Information |
Interpretation |
|
| Solubility - In water at 20oC (mg l-1) | 2.28 | A5 | Low | |
| Solubility - In organic solvents at 20oC (mg l-1) | 1000000 | A5 - Acetone | - | |
| 144000 | A5 - Methanol | - | ||
| 1000000 | A5 - Ethyl acetate | - | ||
| 1000000 | A5 - Xylene | - | ||
| Melting point (oC) | 41 | A5 | - | |
| Boiling point (oC) | - | - | - | |
| Degradation point (oC) | - | - | - | |
| Flashpoint (oC) | - | - | - | |
| Octanol-water partition coefficient at pH 7, 20oC | P | 2.82 X 1004 | Calculated | - |
| Log P | 4.45 | A5 | High | |
| Bulk density (g ml-1)/Specific gravity | 1.291 | A5 | - | |
| Dissociation constant (pKa) at 25oC | Not applicable | A5 | - | |
| Note: No dissociation | ||||
| Vapour pressure at 20oC (mPa) | 0.13 | A5 | Low volatility | |
| Henry's law constant at 25oC (Pa m3 mol-1) | 0.2102 | A5 | Moderately volatile | |
GUS leaching potential index  |
1.37 | Calculated | Low leachability | |
| SCI-GROW groundwater index (μg l-1) for a 1 kg ha-1 or 1 l ha-1 application rate |
Value | 3.58 X 10-03 | Calculated | - |
| Note | - | |||
| Potential for particle bound transport index |
- | Calculated | Low | |
| Maximum UV-vis absorption L mol-1 cm-1 | No absorption >290nm | A5 | - | |
| Surface tension (mN m-1) | - | - | - | |
Degradation:
| Property |
Value | Source/Quality Score/Other Information |
Interpretation |
General biodegradability | - |
| Soil degradation (days) (aerobic) | DT50 (typical) | 4.4 | A5 | Non-persistent |
| DT50 (lab at 20oC) | 4.4 | A5 | 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 | - | - | - |
| Note | - | |||
| Aqueous photolysis DT50 (days) at pH 7 | Value | 1 | A3 | Moderately fast |
| Note | - | |||
| Aqueous hydrolysis DT50 (days) at 20oC and pH 7 | Value | - | - | - |
| Note | - | |||
| Water-sediment DT50 (days) | - | - | - | |
| Water phase only DT50 (days) | - | - | - | |
Soil adsorption and mobility:
| Property |
Value | Source/Quality Score/Other Information |
Interpretation |
|
| Linear | Kd | - | A3 | Mobile |
| Koc | 74 | |||
| Notes and range | EU dossier value for MCPA | |||
| Freundlich | Kf | - | - | - |
| Kfoc | - | |||
| 1/n | - | |||
| Notes and range | - | |||
| pH sensitivity | - | |||
Key metabolites:
| Metabolite | Formation medium | Estimated maximum occurrence fraction | 1107/2009 relevancy |
|
| MCPA (Ref: BAS 009H) |
Soil | 0.66 | Major fraction, Relevant | |
| 2-methyl-4-chlorophenol |
Soil | 0.198 | Major fraction, Relevant | |
ECOTOXICOLOGY
for MCPA-thioethyl
| Property |
Value | Source/Quality Score/Other Information |
Interpretation |
|
| Bio-concentration factor | BCF (l kg-1) | - | - | - |
| CT50 (days) | - | - | ||
| Mammals - Acute oral LD50 (mg kg-1) | 450 | A5 Rat | Moderate | |
| Mammals - Short term dietary NOEL | (mg kg-1) | - | - | - |
| (ppm diet) | - | - | ||
| Birds - Acute LD50 (mg kg-1) | > 400 | A4 Colinus virginianus | Moderate | |
| Birds - Short term dietary (LC50/LD50) | > 1040 mg kg feed-1 | A3 Colinus virginianus | - | |
| Fish - Acute 96 hour LC50 (mg l-1) | 0.3 | A5 Oncorhynchus mykiss | Moderate | |
| Fish - Chronic 21 day NOEC (mg l-1) | 0.2 | A5 Salmo gairneri | Moderate | |
| Aquatic invertebrates - Acute 48 hour EC50 (mg l-1) | 0.58 | A5 Daphnia magna | Moderate | |
| Aquatic invertebrates - Chronic 21 day NOEC (mg l-1) | 0.009 | A5 Daphnia magna | High | |
| 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) | > 2.3 | A5 Scenedemus subspicatus | Moderate | |
| Algae - Chronic 96 hour NOEC, growth (mg l-1) | - | - | - | |
| 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) | > 100 | A4, as formulation | Low | |
| 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) | - | - | - |
| - | ||||
| 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) | - | - | - |
| Mode of exposure | - | |||
| 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) | 140.5 | A5 | 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 | - | - | - | |
| Other arthropod (2) | LR50 g ha-1 | - | - | - |
| % Effect | - | - | - | |
| Soil micro-organisms | Nitrogen mineralisation: No significant adverse effect Carbon mineralisation: No significant adverse effect |
A5 Dose: 1.224 kg ha-1, 28 days |
- | |
| Mesocosm study data | NOEAEC mg l-1 | - | - | - |
| NOEAEC mg l-1 | - | - | - | |
HUMAN HEALTH AND PROTECTION
for MCPA-thioethyl
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) | 450 | A5 Rat | Moderate | |
| Mammals - Dermal LD50 (mg kg-1 body weight) | > 5000 | A5 Rat | - | |
| Mammals - Inhalation LC50 (mg l-1) | 0.044 | L3 Rat, 4 hr | - | |
| Other Mammal toxicity endpoints | - | - | ||
| ADI - Acceptable Daily Intake (mg kg-1bw day-1) | 0.013 | A5 Rat, SF=100 | - | |
| ARfD - Acute Reference Dose (mg kg-1bw day-1) | 0.15 | A5 Rabbit, SF=100 | - | |
| AAOEL - Acute Acceptable Operator Exposure Level (mg kg-1 bw day-1) | - | - | - | |
| AOEL - Acceptable Operator Exposure Level - Systemic (mg kg-1bw day-1) | 0.04 | A5 Rat, SF=100 | - | |
| Dermal penetration studies (%) | - | - | - | |
| Dangerous Substances Directive 76/464 | List II as MCPA | - | - | |
| 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 | |||
|
A3; B0; C0; D0; E0 | - |
- |
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| Respiratory tract irritant | Skin irritant | Skin sensitiser | Eye irritant | Phototoxicant | ||||
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| General human health issues | Highly toxic | |||||||
| 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 |
|
| General |
Not explosive | |||
| CLP classification 2013 | Health: H302 Environment: H400, H410 |
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| EC Risk Classification |
Xn - Harmful: R22, R41 Xi - Irritant: R38 |
|||
| EC Safety Classification |
S2, S26, S37, S39 | |||
| WHO Classification | II | - | Moderately hazardous | |
| UN Number | - | |||
| Waste disposal & packaging |
- | |||
TRANSLATIONS
for MCPA-thioethyl
| Language | Name |
| English | MCPA-thioethyl |
| French | - |
| German | - |
| Danish | - |
| Italian | - |
| Spanish | - |
| Greek | - |
| Slovenian | - |
| Polish | MCPA tioetyl |
| Swedish | - |
| Hungarian | - |
| Dutch | - |
Record last updated: Monday 28 October 2019
Contact: aeru@herts.ac.uk