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

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GENERAL INFORMATION
for dimethachlor

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

Introduction: 1977

EC Regulation 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

for dimethachlor

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

for dimethachlor

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

for dimethachlor

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)


TRANSLATIONS

for dimethachlor

Language Name
English dimethachlor
French dimethachlore
German Dimethachlor
Danish dimethachlor
Italian dimetaclor
Spanish dimetacloro
Greek dimethachlor
Slovenian dimetaklor
Polish dimetachlor
Swedish -
Hungarian dimetaklor
Dutch -

Record last updated: Monday 09 September 2013
Contact: aeru@herts.ac.uk
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