MCPB (Ref: MB 3046) ** 2,4-MCPB ** L-338 ** MCPB acid ** Translations

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GENERAL INFORMATION
for MCPB

Description: A herbicide for post-emergence control of annual and perennial broad-leaved weeds

Example pests controlled: Thistles; Docks; Buttercups; Fat hen; Shepherds purse; Nightshade; Nettles; Plantains; Ragwort; Hedge mustard; Bindweed

Example applications: Newly sown pastures; Clover seed crops; Peas; cereals undersown with ryegrass or clover

Efficacy & activity: -

Availability status: Current

Introduction & key dates: circa 1960

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

Status	Approved
Dossier rapporteur/co-rapporteur	Poland/Netherlands
Date inclusion expires	31/10/2019
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

Chemical structure:

Isomerism	-
Chemical formula	C11H13ClO3
Canonical SMILES	CC1=C(C=CC(=C1)Cl)OCCCC(=O)O
Isomeric SMILES	No data
International Chemical Identifier key (InChIKey)	LLWADFLAOKUBDR-UHFFFAOYSA-N
International Chemical Identifier (InChI)	InChI=1S/C11H13ClO3/c1-8-7-9(12)4-5-10(8)15-6-2-3-11(13)14/h4-5,7H,2-3,6H2,1H3,(H,13,14)
Structure diagram/image available?	Yes

General status:

Pesticide type	Herbicide
Substance group	Aryloxyalkanoic acid
Minimum active substance purity	840 g/kg
Known relevant impurities	EU dossier - free phenols <30g/Kg as 4-chloro-2-methylphenol, triethanolamine insolubles <1g/kg
Substance origin	Synthetic
Mode of action	Selective, systemic, absorbed by leaves and roots with translocation. Synthetic auxin.
CAS RN	94-81-5
EC number	202-365-3
CIPAC number	50
US EPA chemical code	019201
PubChem CID	7207
Molecular mass (g mol-1)	228.67
PIN (Preferred Identification Name)	-
IUPAC name	4-(4-chloro-o-tolyloxy)butyric acid
CAS name	4-(4-chloro-2-methylphenoxy)butanoic acid
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	White powder
Related substances & organisms	bentazone

Formulations:

Property	Value
Example manufacturers & suppliers of products using this active now or historically	BASF Headland Nufarm United Phosphorus
Example products using this active	Butoxone Tropotox Tropotox Plus Thistrol
UK LERAP status	None
Formulation and application details	Often supplied as soluble concentrate or in liquid formulations.

ENVIRONMENTAL FATE
for MCPB

Property		Value	Source/Quality Score/Other Information	Interpretation
Solubility - In water at 20oC (mg l-1)		4400	A5	High
Solubility - In organic solvents at 20oC (mg l-1)		313000	A5 - Acetone	-
		169000	A5 - Dichloromethane	-
		266	C4 - Hexane	-
		150000	L3 - Ethanol	-
Melting point (oC)		98	A5	-
Boiling point (oC)		623	A4 - (some decomposition)	-
Degradation point (oC)		623	A5	-
Flashpoint (oC)		Not expected to self ignite; Not highly flammable	A5	-
Octanol-water partition coefficient at pH 7, 20oC	P	2.09 X 1001	Calculated	-
	Log P	1.32	A5	Low
Bulk density (g ml-1)/Specific gravity		1.233	A5	-
Dissociation constant (pKa) at 25oC		4.5	A5	-
		Note: Weak acid
Vapour pressure at 20oC (mPa)		0.004	A5	Low volatility
Henry's law constant at 25oC (Pa m3 mol-1)		3.0 X 10-05	A5	Non-volatile
GUS leaching potential index		1.64	Calculated	Low leachability
SCI-GROW groundwater index (μg l-1) for a 1 kg ha-1 or 1 l ha-1 application rate	Value	1.03 X 10-02	Calculated	-
	Note	-
Potential for particle bound transport index		-	Calculated	Low
Maximum UV-vis absorption L mol-1 cm-1		228nm = 9827, 278nm = 1714	A5	-
Surface tension (mN m-1)		-	-	-

Degradation:

Property		Value	Source/Quality Score/Other Information	Interpretation
General biodegradability		-
Soil degradation (days) (aerobic)	DT50 (typical)	7	A5	Non-persistent
	DT50 (lab at 20oC)	6.8	A5	Non-persistent
	DT50 (field)	-	-	-
	DT90 (lab at 20oC)	22.6	A5	-
	DT90 (field)	-	-	-
	DT50 modelling endpoint	-	-	-
	Note	EU dossier Lab studies DT50 range 2-11 days
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	2.6	A5	Moderately fast
	Note	Rapid photolysis at pH 5 to pH 9 under irradiated conditions
Aqueous hydrolysis DT50 (days) at 20oC and pH 7	Value	Stable	A5	-
	Note	Stable pH 5 to pH 9, 30 days
Water-sediment DT50 (days)		17	A5	Fast
Water phase only DT50 (days)		9.7	A5	Moderately fast

Soil adsorption and mobility:

Property		Value	Source/Quality Score/Other Information	Interpretation
Linear	Kd	-	-	-
	Koc	-
	Notes and range	-
Freundlich	Kf	-	A5	Moderately mobile
	Kfoc	108
	1/n	0.819
	Notes and range	EU dossier Kfoc range 86-130 mL/g
pH sensitivity		Adsorption increases as pH decreases

Key metabolites:

Metabolite		Formation medium	Estimated maximum occurrence fraction	1107/2009 relevancy
MCPA (Ref: BAS 009H)		Soil	0.062	Minor fraction, Relevant
cloxyfonac		Soil	0.095	Minor fraction, Not relevant

ECOTOXICOLOGY
for MCPB

Property		Value	Source/Quality Score/Other Information	Interpretation
Bio-concentration factor	BCF (l kg-1)	Low risk	A5 Based on LogP < 3	Low potential
	CT50 (days)	-		-
Mammals - Acute oral LD50 (mg kg-1)		4300	A5 Rat	Low
Mammals - Short term dietary NOEL	(mg kg-1)	-	L2 Rat, 2 year	-
	(ppm diet)	> 100		-
Birds - Acute LD50 (mg kg-1)		282	A5 Colinus virginianus	Moderate
Birds - Short term dietary (LC50/LD50)		> 5000 mg kg feed-1	A5 Colinus virginianus	-
Fish - Acute 96 hour LC50 (mg l-1)		4.3	A5 Oncorhynchus mykiss	Moderate
Fish - Chronic 21 day NOEC (mg l-1)		40	A5 Oncorhynchus mykiss	Low
Aquatic invertebrates - Acute 48 hour EC50 (mg l-1)		55	A5 Daphnia magna	Moderate
Aquatic invertebrates - Chronic 21 day NOEC (mg l-1)		50	A5 Daphnia magna	Low
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)		37	A5 Lemna gibba	Low
Non-target plants		-	-	-
		-	-	-
Algae - Acute 72 hour EC50, growth (mg l-1)		41.0	A5 Pseudokirchneriella subcapitata	Low
Algae - Chronic 96 hour NOEC, growth (mg l-1)		-	-	-
Honeybees	Contact acute 48 hour LD50 (μg bee-1)	> 100	A5	Low
	Oral acute 48 hour LD50 (μg bee-1)	> 81.8	A5	Moderate
	Unknown mode acute 48 hour LD50 (μg bee-1)	-	-	-
Earthworms - Acute 14 day LC50 (mg kg-1)		> 252	Q3	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	4000	> A5 Aphidius rhopalosiphi	-
	% Effect	-	-	-
Other arthropod (2)	LR50 g ha-1	2000	> A5 Typhlodromus pyri	-
	% Effect	-	-	-
Soil micro-organisms		Nitrogen mineralisation: Effect noted but recovery by day 42 Carbon mineralisation: No significant adverse effect	A5 Dose: 10 kg ha-1	-
Mesocosm study data	NOEAEC mg l-1	-	-	-
	NOEAEC mg l-1	-	-	-

HUMAN HEALTH AND PROTECTION
for MCPB

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)		4300	A5 Rat	Low
Mammals - Dermal LD50 (mg kg-1 body weight)		> 2000	A5 Rat	-
Mammals - Inhalation LC50 (mg l-1)		> 1.14	A5 Rat, 4 hr	-
Other Mammal toxicity endpoints		-		-
ADI - Acceptable Daily Intake (mg kg-1bw day-1)		0.01	A5 Rat, SF=100	-
ARfD - Acute Reference Dose (mg kg-1bw day-1)		0.05	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)		0.06	A5 Rat, SF=100	-
Dermal penetration studies (%)		-	-	-
Dangerous Substances Directive 76/464		-	-	-
Exposure Limits		-	-	-
Exposure Routes	Public	-
	Occupational	Occupational exposure may occur through dermal contact and inhalation of dust and sprays
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		Harmful or fatal if swallowed Causes irreversible eye damage

: 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 IMDG Transport Code is usually 9
CLP classification 2013		Environment: H400, H410
EC Risk Classification		N - Dangerous for the environment: R50, R53
EC Safety Classification		S60, S61
WHO Classification		II	-	Moderately hazardous
US EPA Classification (formulation)		III	-	Caution - Slightly toxic
UN Number		Usually 3082
Waste disposal & packaging		Packaging Group III (minor danger)

TRANSLATIONS
for MCPB

Language	Name
English	MCPB
French	MCPB
German	MCPB
Danish	MCPB
Italian	MCPB
Spanish	MCPB
Greek	MCPB
Slovenian	MCPB
Polish	MCPB
Swedish	MCPB
Hungarian	MCPB
Dutch	MCPB

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Record last updated: Monday 05 November 2018
Contact: aeru@herts.ac.uk