dimethachlor (Ref: CGA 17020) ** dimethachlore ** Translations

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GENERAL INFORMATION

Description: A herbicide used pre-emergence to control most annual grasses and broad-leaved weeds

Introduction: 1977

EC Directive 1107/2009 (repealing 91/414):

Status	Approved
Dossier rapporteur/co-rapporteur	Germany
Date inclusion expires	31/12/2019

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

HU

IE

IT

LT

LU

LV

MT

NL

PL

PT

RO

SE

SI

SK

UK

General status:

Pesticide type	Herbicide
Substance group	Chloroacetamide
Substance origin	Synthetic
Mode of action	Selective, absorbed by new shoots of seedlings and roots
CAS RN	50563-36-5
EC number	256-625-6
CIPAC number	688
US EPA chemical code	-
Chiral molecule	No
Chemical formula	C13H18ClNO2
SMILES	ClCC(=O)N(c1c(cccc1C)C)CCOC
International Chemical Identifier (InChI)	InChI=1/C13H18ClNO2/c1-10-5-4-6-11(2)13(10)15(7-8-17-3)12(16)9-14/h4-6H,7-9H2,1-3H3
Structure diagram/image available?	Yes
Molecular mass (g mol-1)	255.74
IUPAC name	2-chloro-N-(2-methoxyethyl)acet-2',6'-xylidide
CAS name	2-chloro-N-(2,6-dimethylphenyl)-N-(2-methoxyethyl)acetamide
Other status information	-
Herbicide Resistance Classification (HRAC)	K3
Insecticide Resistance Classification (IRAC)	Not applicable
Fungicide Resistance Classification (FRAC)	Not applicable
Physical state	Colourless crystals
Related substances & organisms	-

Formulations:

Property	Value
Example manufacturers of products using this active	-
Example products using this active	Teridox 500Ec
UK LERAP status	No UK approval for use or outside scope
Formulation and application details	Usually supplied as an emulsifiable concentrate that is mixed with water and used as a spray.

ENVIRONMENTAL FATE

Property		Value	Source/Quality Score/Other Information	Interpretation
Solubility - In water at 20oC (mg l-1)		2300	A5	High
Solubility - In organic solvents at 20oC (mg l-1)		500000	A5 - Methanol	-
		500000	A5 - Acetone	-
		42000	A5 - Hexane	-
		440000	A5 - Octanol	-
Melting point (oC)		46.3	A5	-
Boiling point (oC)		Decomposes before boiling	A4	-
Degradation point (oC)		300	A4	-
Flashpoint (oC)		Not expected to self ignite; Not highly flammable	A5	-
Octanol-water partition coefficient at pH 7, 20oC	P	1.48 X 1002	Calculated	-
	Log P	2.17	A5	Low
Bulk density (g ml-1)/Specific gravity		1.23	L3	-
Dissociation constant (pKa) at 25oC		Not applicable	A5	-
		Note: No dissociation
Vapour pressure at 25oC (mPa)		0.64	A5	Non-volatile
Henry's law constant at 25oC (Pa m3 mol-1)		1.70 X 10-04	A5	Non-volatile
Henry's law constant at 20oC (dimensionless)		2.92 X 10-08	Calculated	Non-volatile
GUS leaching potential index		1.83	Calculated	Transition state
SCI-GROW groundwater index (µg l-1) for a 1 kg ha-1 or 1 l ha-1 application rate	Value	8.68 X 10-03	Calculated	-
	Note	-
Potential for particle bound transport index		-	Calculated	Low
Maximum UV-vis absorption L mol-1 cm-1		Neutral solution: 215nm = 14461, 265nm = 486; [Acidic solution: 215nm = 14768, 265nm = 572; [Basic solution: 215nm = 9576, 265nm = 469	A5	-
Surface tension (mN m-1)		57.2-66.1	A4 at 20oC, 0.19-1.9 g l-1	-

Degradation:

Property		Value	Source/Quality Score/Other Information	Interpretation
Soil degradation (days) (aerobic)	DT50 (typical)	7	A5	Non-persistent
	DT50 (lab at 20oC)	6.5	A5	Non-persistent
	DT50 (field)	3.2	A5	Non-persistent
	DT90 (lab at 20oC)	27.8	A5	-
	DT90 (field)	10.5	A5	-
	Note	EU dossier lab studies DT50 range 2.3 (silt loam) - 15.6 (loamy sand) days, DT90 range 11-65.9 days
Aqueous photolysis DT50 (days) at pH 7	Value	Stable	A5	Stable
	Note	-
Aqueous hydrolysis DT50 (days) at 20oC and pH 7	Value	200	A5	Persistent
	Note	Stable pH 1 to pH 9, DT50 9.3 days at pH 13 up to 50 degC
Water-Sediment DT50 (days)		14.1	A5	Fast
Water phase only DT50 (days)		10	A5	Moderately fast

Soil adsorption and mobility:

Property		Value	Source/Quality Score/Other Information	Interpretation
Linear	Kd	-	-	-
	Koc	-
	Notes and range	-
Freundlich	Kf	4.20	A5	Mobile
	Kfoc	69
	1/n	0.91
	Notes and range	EU dossier kf range 0.32-18.4, Kfoc range 29.7-128 mL/g, 1/n range 0.760-0.939, Soils=10
pH sensitivity		No

Key metabolites:

Metabolite		Formation medium	Estimated maximum occurrence fraction	91/414 relevancy
N-(2,6-dimethylphenyl)-N-(2-methoxyethyl)oxalamic acid (Ref: CGA 50266)		Soil	0.355	Major fraction, Relevant
[(2,6-dimethylphenyl)-2-methoxyethyl)carbamoyl]methanesulfonic acid sodium salt (Ref: CGA 354742)		Soil	0.158	Major fraction, Relevant

Other known metabolites:

Metabolite name and reference	Aliases	Formation medium / Rate	Estimated maximum occurrence fraction	Metabolising enzymes
IMPURITY	-	-	-	-
N-carboxymethyl-N-(2,6-dimethyl-phenyl)oxalamic acid (Ref: CGA 102935) Note: Risk to groundwater	-	Soil (Aerobic)	-	-
(2,6-dimethylphenylcarbamoyl)-methanesulfonic acid sodium salt (Ref: CGA 369873) Note: Detected in lysimeter leachate; Risk to groundwater	-	Soil (Aerobic); Groundwater	-	-
[(2,6-dimethylphenyl)-(2-sulfo-acetyl)amino]acetic acid sodium salt (Ref: CGA 373464) Note: Detected in lysimeter leachate; Risk to groundwater	-	Soil (Aerobic)	-	-
N-(2,6-dimethylphenyl)-N-(2-methoxyethyl)acetamide (Ref: CGA 42443)	-	Soil (Anaerobic); Water/sediment	-	-
2,6-dimethylaniline (Ref: CGA 72649)	-	Not applicable	-	-
3-{2-[(2,6-dimethyl-phenyl)-(2-hy-droxyacetyl)amino]ethylsulfanyl}-2-hydroxypropionic acid (Ref: SYN 528702) Note: Risk to groundwater	-	Soil (Aerobic)	-	-
2-[(2-hydroxyacetyl)-(2-methoxy-ethyl)amino]-3-methylbenzoic acid (Ref: SYN 530561) Note: Detected in lysimeter leachate; Risk to groundwater	-	Soil (Aerobic)	-	-

ECOTOXICOLOGY

Property		Value	Source/Quality Score/Other Information	Interpretation
Bio-concentration factor	BCF	75	Q2 Estimated	Low potential
	CT50 (days)	Not available		-
Bioaccumulation potential		-	Calculated	Low
Mammals - Acute oral LD50 (mg kg-1)		1600	A5 Rat	Moderate
Mammals - Short term dietary NOEL	(mg kg-1)	> 12	L2 Rat, 2 year	High
	(ppm diet)	> 300		-
Birds - Acute LD50 (mg kg-1)		524	A5 Coturnix japonica	Moderate
Birds - Short term dietary (LC50/LD50)		> 1470 mg kg bw-1 day-1	A5 Coturnix japonica	-
Fish - Acute 96 hour LC50 (mg l-1)		3.9	A5 Oncorhynchus mykiss	Moderate
Fish - Chronic 21 day NOEC (mg l-1)		0.85	A5 Oncorhynchus mykiss	-
Aquatic invertebrates - Acute 48 hour EC50 (mg l-1)		24	A5 Daphnia magna	Moderate
Aquatic invertebrates - Chronic 21 day NOEC (mg l-1)		2.3	A5 Daphnia magna	-
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)		4.0	A5 Chironomus riparius	Moderate
Sediment dwelling organisms - Chronic 28 day NOEC, sediment (mg kg-1)		25.0	A5 Chironomus riparius	Moderate
Aquatic plants - Acute 7 day EC50, biomass (mg l-1)		0.035	A5 Lemna gibba	Moderate
Algae - Acute 72 hour EC50, growth (mg l-1)		0.0065	A5 Pseudokirchneriella subcapitata	High
Algae - Chronic 96 hour NOEC, growth (mg l-1)		-	-	-
Honeybees - Acute 48 hour LD50 (µg bee-1)		> 200	A5 Contact	Low
Earthworms - Acute 14 day LC50 (mg kg-1)		70	A5 Eisenia foetida corr	Moderate
Earthworms - Chronic 14 day NOEC, reproduction (mg kg-1)		-	-	-
Other soil macro-organisms - e.g. Collembola	LR50 / EC50 / NOEC / % Effect	-	-	-
Other arthropod (1)	LR50 g ha-1	91	48 hour A5 Aphidius rhopalosiphi, adult	Moderately harmful at 1 kg ha-1 Harmless at 0.1 kg ha-1 Harmless at 0.01 kg ha-1
	% Effect	-	-	-
Other arthropod (2)	LR50 g ha-1	655	7 day A5 Typhlodromus pyri	Harmless at 1 kg ha-1 Harmless at 0.1 kg ha-1 Harmless at 0.01 kg ha-1
	% Effect	-	-	-
Soil micro-organisms		Nitrogen mineralisation: No significant adverse effect Carbon mineralisation: No significant adverse effect	A5 Dose: 7.5 kg ha-1, 28 days	-
Mesocosm study data	NOEAEC mg l-1	-	-	-
	NOEAEC mg l-1	-	-	-

HUMAN HEALTH AND PROTECTION

General:

Property		Value	Source/Quality Score/Other Information	Interpretation
Mammals - Acute oral LD50 (mg kg-1)		1600	A5 Rat	Moderate
Mammals - Dermal LD50 (mg kg-1 body weight)		> 2000	A5 Rat	-
Mammals - Inhalation LC50 (mg l-1)		> 4.45	A5 Rat, 4 hr (nose only)	-
Other Mammal toxicity endpoints		-		-
ADI - Acceptable Daily Intake (mg kg-1bw day-1)		0.1	A5 Rat, SF=100	-
ARfD - Acute Reference Dose (mg kg-1bw day-1)		0.5	A5 Rat, SF=100	-
AOEL - Acceptable Operator Exposure Level - Systemic (mg kg-1bw day-1)		0.1	A5 Dog, SF=100	-
Dermal penetration studies (%)		3.0-10.0	A5 concentration dependant	-
Dangerous Substances Directive 76/464		-	-	-
Exposure Limits		-	-	-
Exposure Routes	Public	No unacceptable risks to bystanders identified
	Occupational	No unacceptable risks to operators or other workers identified
Examples of European MRLs (mg kg-1)	Value	Rapeseed: 0.05
	Note	A5 EU dossier proposals For the EU pesticides database click here
Drinking Water MAC (µg l-1)		0.1	EU Dir 89/778/EC limit; A5	-

Health issues:

Carcinogen	Mutagen	Endocrine disrupter	Reproduction / development effects	Acetyl cholinesterase inhibitor	Neurotoxicant	Respiratory tract irritant	Skin irritant	Eye irritant
	-	-
General human health issues		Skin sensitiser

: Yes, known to cause a problem
: No, known not to cause a problem
: Possibly, status not identified
- : No data

Handling issues:

Property		Value	Source/Quality Score/Other Information	Interpretation
General		Not explosive or oxidising IMDG Transport Code is usually 9
CLP classification 2013		-
EC Risk Classification		Xn - Harmful: R22, R43 N - Dangerous for the environment: R50, R53
EC Safety Classification		S2, S24, S37, S60, S61
WHO Classification		II	-	Moderately hazardous
US EPA Classification (formulation)		No consensus across products or no products available	-	-
UN Number		Usualy 3077
Waste disposal & packaging		Packaging Group III (minor danger)

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