metalaxyl (Ref: CGA 48988) ** Translations

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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

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
2D structure diagram/image available?	Yes

Cambridge Crystallographic Data Centre diagrams:

Common Name	Relationship	Link
Metalaxyl	Unstated isomer

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	Clayton ISK Biosciences Europe SA Syngenta Ciba-Giegy
Example products using this active	Apron Ridomil Subdue
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)	-	-

ECOTOXICOLOGY
for metalaxyl

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
Respiratory tract irritant	Skin irritant	Skin sensitiser	Eye irritant	Phototoxicant
				-
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

: 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
EC Risk Classification		Xn - Harmful: R22, R43 N - Dangerous for the environment: R52, R53
EC Safety Classification		S2, S13, S24, S37, S46, S61
WHO Classification		II	-	Moderately hazardous
US EPA Classification (formulation)		-	-
UN Number		-
Waste disposal & packaging		-

TRANSLATIONS
for metalaxyl

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

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Record last updated: Wednesday 31 October 2018
Contact: aeru@herts.ac.uk