| metalaxyl (Ref: CGA 48988) |
 |
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GENERAL INFORMATION 
for metalaxyl
Description: A fungicide used to control diseases caused by air- and soil-borne Peronosporales in many different crops
Example pests controlled: Downy mildew; Foliar and tuber blight; Damping-off
Example applications: Many agricultural crops including tobacco, potaoes, soybean, onions, citrus, cucubits, tomatoes, cotton; Ornamentals; Turf
Efficacy & activity: -
Availability status: Current
Introduction & key dates: 1977, first reported; 1979, first marketed
EC Regulation 1107/2009 (repealing 91/414):
| Status | Approved |
| Dossier rapporteur/co-rapporteur | Spain/Portugal |
| Date inclusion expires | 30/06/2023 |
| EU Candidate for substitution (CfS) | Yes - non-active isomers |
| 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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Also used in: Australia, USA
Chemical structure:
| Isomerism | A chiral molecule that exists in the R- and S-forms |
| Chemical formula | C15H21NO4 |
| Canonical SMILES | CC1=C(C(=CC=C1)C)N(C(C)C(=O)OC)C(=O)COC |
| Isomeric SMILES | No data |
| International Chemical Identifier key (InChIKey) | ZQEIXNIJLIKNTD-UHFFFAOYSA-N |
| International Chemical Identifier (InChI) | InChI=1S/C15H21NO4/c1-10-7-6-8-11(2)14(10)16(13(17)9-19-4)12(3)15(18)20-5/h6-8,12H,9H2,1-5H3 |
| Structure diagram/image available? | Yes |
General status:
| Pesticide type | Fungicide | |||
| Substance group | Phenylamide | |||
| Minimum active substance purity | 950 g/kg | |||
| Known relevant impurities | EU dossier: 2,6-dimenthylaniline < 1 g/kg | |||
| Substance origin | Synthetic | |||
| Mode of action | Systemic with curative and protective action, acts by suppressing sporangial formation, mycelial growth and the establishment of new infectons. Disrupts fungal nucleic acid synthesis - RNA ploymerase 1. | |||
| CAS RN | 57837-19-1 | |||
| EC number | 260-979-7 | |||
| CIPAC number | 365 | |||
| US EPA chemical code | 113501 | |||
| PubChem CID | 42586 | |||
| Molecular mass (g mol-1) | 279.33 | |||
| PIN (Preferred Identification Name) | - | |||
| IUPAC name | methyl N-(methoxyacetyl)-N-(2,6-xylyl)-DL-alaninate | |||
| CAS name | methyl N-(2,6-dimethylphenyl)-N-(methoxyacetyl)-DL-alaninate | |||
| Other status information | Potential groundwater contaminant | |||
| Relevant Environmental Water Quality Standards | - | |||
| Herbicide Resistance Classification (HRAC) | Not applicable | |||
| Herbicide Resistance Classification (WSSA) | Not applicable | |||
| Insecticide Resistance Classification (IRAC) | Not applicable | |||
| Fungicide Resistance Classification (FRAC) | 4 | |||
| Examples of recorded resistance | - | |||
| Physical state | Colourless to white fine crystals | |||
| 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 | Buffer probably required in UK - see product label | |||
| Formulation and application details | Foliar application. Available in a variety of different formulations including granules, wettable powders and emulsifiable concentrates. | |||
ENVIRONMENTAL FATE
for metalaxyl
| Property |
Value | Source/Quality Score/Other Information |
Interpretation |
|
| Solubility - In water at 20oC (mg l-1) | 8400 | A4 - @ 22 DegC, pH 5.2 | High | |
| Solubility - In organic solvents at 20oC (mg l-1) | 550000 | C4 - Benzene | - | |
| 9100 | C4 - Hexane | - | ||
| 650000 | C4 - Methanol | - | ||
| Miscible | A5 - Toluene | - | ||
| Melting point (oC) | 72.0 | A5 | - | |
| Boiling point (oC) | - | - | - | |
| Degradation point (oC) | - | - | - | |
| Flashpoint (oC) | Not expected to self ignite; Not highly flammable | A5 | - | |
| Octanol-water partition coefficient at pH 7, 20oC | P | 5.62 X 1001 | Calculated | - |
| Log P | 1.75 | A4 - @ 25 DegC | Low | |
| Bulk density (g ml-1)/Specific gravity | 1.2 | A5 | - | |
| Dissociation constant (pKa) at 25oC | 0 | L3 | - | |
| Note: Very strong acid | ||||
| Vapour pressure at 20oC (mPa) | 0.75 | A5 | Low volatility | |
| Henry's law constant at 25oC (Pa m3 mol-1) | 1.60 X 10-05 | A5 | Non-volatile | |
GUS leaching potential index  |
2.79 | Calculated | Transition state | |
| SCI-GROW groundwater index (μg l-1) for a 1 kg ha-1 or 1 l ha-1 application rate |
Value | 2.12 X 10-01 | Calculated | - |
| Note | - | |||
| Potential for particle bound transport index |
- | Calculated | Low | |
| Maximum UV-vis absorption L mol-1 cm-1 | Max at 206nm 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) | 36 | A5 | Moderately persistent |
| DT50 (lab at 20oC) | 36 | A5 | Moderately persistent | |
| DT50 (field) | 38.7 | A5 | Moderately persistent | |
| DT90 (lab at 20oC) | 86 | A5 | - | |
| DT90 (field) | - | - | - | |
| DT50 modelling endpoint | - | - | - | |
| Note | EU dossier Lab studies DT50 range 33-42 days, DT90 range 45-126 days; Field studties DT50 range 19.5-113 days; Other sources: DT50 70 days (DW4) | |||
| Dissipation rate RL50 on plant matrix | Value | 9.2 | R4 | - |
| Note | Published literature RL50 range 2.5-16.0 days, 3 field & undercover grown crops, various matrices, n=3 | |||
| Dissipation rate RL50 on and in plant matrix | Value | 5.7 | R4 | - |
| Note | Published literature RL50 range 0.8-22.5 days, 16 field & undercover crops, various matrices, n=31; Lab study with bentgrass, RL50=100 days | |||
| Aqueous photolysis DT50 (days) at pH 7 | Value | Stable | R3 | - |
| Note | - | |||
| Aqueous hydrolysis DT50 (days) at 20oC and pH 7 | Value | 106 | K4 | Persistent |
| Note | pH sensitive: DT50 200 days at pH 1, 115 days at pH 9, 12 days at pH 10, all at 20 degC | |||
| Water-sediment DT50 (days) | 56 | K4 | Moderately fast | |
| Water phase only DT50 (days) | 56 | K4 | Stable | |
Soil adsorption and mobility:
| Property |
Value | Source/Quality Score/Other Information |
Interpretation |
|
| Linear | Kd | - | A5 | Moderately mobile |
| Koc | 162 | |||
| Notes and range | - | |||
| Freundlich | Kf | 2.49 | A5 | Moderately mobile |
| Kfoc | 162.3 | |||
| 1/n | 0.98 | |||
| Notes and range | EU dossier Kf range 0.4-1.4 mL/g, Kfoc range 29.6-283.8 mL/g, 1/n range 0.766-1.257, Soils=4; Literature data: Kf range 0.01-8.01 mL/g, Kfoc range 28-284 mL/g, 1.n range 0.57-1.32, Soils = 27 | |||
| pH sensitivity | No | |||
Key metabolites:
| Metabolite | Formation medium | Estimated maximum occurrence fraction | 1107/2009 relevancy |
|
| N-(2,6-dimethylphenyl)-N-(methoxyacetyl)alanine (Ref: CGA 62826 (racemate)) |
Soil | 0.536 | - | |
Other known metabolites:
| Metabolite name and reference | Aliases | Formation medium / Rate | Estimated maximum occurrence fraction | Metabolising enzymes |
| 2,6-dimethylacetanilide | - | Soil (Aerobic) | - | - |
| N-(3-hydroxy-2,6-dimethylphenyl)-N-(methoxyacetyl)-L-alanine | - | Water (Anaerobic) | - | - |
| Property |
Value | Source/Quality Score/Other Information |
Interpretation |
|
| Bio-concentration factor | BCF (l kg-1) | 7 | F4 Whole fish | Low potential |
| CT50 (days) | Not available | - | ||
| Mammals - Acute oral LD50 (mg kg-1) | > 669 | A5 Rat | Moderate | |
| Mammals - Short term dietary NOEL | (mg kg-1) | 2.5 | Z2 Rat | High |
| (ppm diet) | - | - | ||
| Birds - Acute LD50 (mg kg-1) | 1466 | A5 Anas platyrhynchos | Moderate | |
| Birds - Short term dietary (LC50/LD50) | > 10000 mg kg feed-1 | A5 Anas platyrhynchos | - | |
| Fish - Acute 96 hour LC50 (mg l-1) | 0.96 | A5 Oncorhynchus mykiss | Moderate | |
| Fish - Chronic 21 day NOEC (mg l-1) | - | - | - | |
| Aquatic invertebrates - Acute 48 hour EC50 (mg l-1) | 3.47 | A5 Daphnia magna | Moderate | |
| Aquatic invertebrates - Chronic 21 day NOEC (mg l-1) | - | - | - | |
| Aquatic crustaceans - Acute 96 hour LC50 (mg l-1) | 0.64 | F3 Americamysis bahia | Moderate | |
| 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) | 85 | F3 Lemna gibba | Low | |
| Non-target plants | - | - | - | |
| - | - | - | ||
| Algae - Acute 72 hour EC50, growth (mg l-1) | 0.42 | A5 Scenedemus subspicatus | Moderate | |
| Algae - Chronic 96 hour NOEC, growth (mg l-1) | 10 | Q2 Unknown species | Low | |
| Honeybees | Contact acute 48 hour LD50 (μg bee-1) | 200 | A5 | Low |
| Oral acute 48 hour LD50 (μg bee-1) | 269 | A5 | Low | |
| Unknown mode acute 48 hour LD50 (μg bee-1) | - | - | - | |
| Earthworms - Acute 14 day LC50 (mg kg-1) | > 1000 | A5 Eisenia foetida | Low | |
| Earthworms - Chronic 14 day NOEC, reproduction (mg kg-1) | 40 | A3 Eisenia foetida, as metalaxyl-M | Moderate | |
| Other soil macro-organisms - e.g. Collembola | LR50 / EC50 / NOEC / % Effect | - | - | - |
| Other arthropod (1) | LR50 g ha-1 | 630 | as g product ha-1 (Armetil Cobre: Conc 8% metalaxyl) A5 Typhlodromus pyri |
- |
| % Effect | - | - | - | |
| Other arthropod (2) | LR50 g ha-1 | 380 | as g product ha-1 (Armetil Cobre: Conc 8% metalaxyl) A5 Aphidius rhopalosiphi |
- |
| % Effect | - | - | - | |
| Soil micro-organisms | Nitrogen mineralisation: No significant adverse effect Carbon mineralisation: No significant adverse effe |
A5 Dose: 5.0 kg ha-1 |
- | |
| Mesocosm study data | NOEAEC mg l-1 | - | - | - |
| NOEAEC mg l-1 | - | - | - | |
HUMAN HEALTH AND PROTECTION
for metalaxyl
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) | > 669 | A5 Rat | Moderate | |
| Mammals - Dermal LD50 (mg kg-1 body weight) | > 5000 | A5 Rat | - | |
| Mammals - Inhalation LC50 (mg l-1) | > 3.6 | A5 Rat | - | |
| Other Mammal toxicity endpoints | - | - | ||
| ADI - Acceptable Daily Intake (mg kg-1bw day-1) | 0.08 | A5, Dog SF=100 | - | |
| ARfD - Acute Reference Dose (mg kg-1bw day-1) | 0.5 | A5 Rat, 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) | 0.08 | A5 Rat, SF=100 | - | |
| Dermal penetration studies (%) | 30 | A5 | - | |
| Dangerous Substances Directive 76/464 | - | - | - | |
| Exposure Limits | - | - | - | |
| 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 | Mutagen | Endocrine disrupter | Reproduction / development effects | Cholinesterase inhibitor | Neurotoxicant | |||
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| Respiratory tract irritant | Skin irritant | Skin sensitiser | Eye irritant | Phototoxicant | ||||
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| General human health issues | Moderately toxic Liver toxicant Not listed as a skin sensitiser in the EU but some evidence available suggesting it may be exists elsewhere A weak inducer of cytochrome P450 |
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: Yes, known to cause a problem
: No, known not to cause a problem
: Possibly, status not identified
- : No data found
Handling issues:
| Property |
Value | Source/Quality Score/Other Information |
Interpretation |
|
| General |
Not explosive | |||
| CLP classification 2013 | Health: H302; H317 Environment: H412 |
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| EC Risk Classification |
Xn - Harmful: R22, R43 N - Dangerous for the environment: R52, R53 |
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| EC Safety Classification |
S2, S13, S24, S37, S46, S61 | |||
| WHO Classification | II | - | Moderately hazardous | |
| US EPA Classification (formulation) | - | - | ||
| UN Number | - | |||
| Waste disposal & packaging |
- | |||
| Language | Name |
| English | metalaxyl |
| French | metalaxyl |
| German | Metalaxyl |
| Danish | metalaxyl |
| Italian | metalaxil |
| Spanish | metalaxil |
| Greek | metalaxyl |
| Slovenian | metalaksil |
| Polish | metalaksyl |
| Swedish | metalaxyl |
| Hungarian | metalaxyl |
| Dutch | metalaxyl |
Record last updated: Wednesday 31 October 2018
Contact: aeru@herts.ac.uk