dichlobenil (Ref: H 133) ** dichlorbenil ** DCBN ** Translations

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SUMMARY

Dichlobenil is a herbicide that was largely used for general annual and perennial weed control in non-copped. It is no longer approved for use within the EU. It has low solubility, is not highly volatle and has potential to leach into groundwater. It is moderately persistent in soils and very persistent in water. It is moderately toxic to mammals, aquatic organisms, honeybees and earthworms.

GENERAL INFORMATION
for dichlobenil

Description: A herbicide for woody crops, non-crop uses and in, for example, established orchards. Can also be a pesticide transformation product

Example pests controlled: Canada thistle; Quackgrass; Timothy; Wild rocket; Fescue; Curly Dock; Knapweed; Spurge; Bluegrass; Crabgrass; Pigweed; Knotweed

Example applications: Fruit including apples, cherry, grape, pear, filbert, blueberry, gooseberry, blackberry, raspberry, loganberry; Non-cropped areas including recreational areas, industrial sites, pathways

Efficacy & activity: -

Availability status: Current

Introduction & key dates: 1960, first reported

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

Status	Not approved
Dossier rapporteur/co-rapporteur	UK
Date inclusion expires	Expired
EU Candidate for substitution (CfS)	Not applicable
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	None
Chemical formula	C7H3Cl2N
Canonical SMILES	C1=CC(=C(C(=C1)Cl)C#N)Cl
Isomeric SMILES	N#Cc1c(Cl)cccc1Cl
International Chemical Identifier key (InChIKey)	YOYAIZYFCNQIRF-UHFFFAOYSA-N
International Chemical Identifier (InChI)	InChI=1S/C7H3Cl2N/c8-6-2-1-3-7(9)5(6)4-10/h1-3H
2D structure diagram/image available?	Yes

General status:

Pesticide type	Herbicide, Metabolite
Metabolite Type	Soil
Substance group	Benzonitrile
Minimum active substance purity	980 g/kg
Known relevant impurities	EU dossier - None declared
Substance origin	Synthetic
Mode of action	Systemic. Inhibition of cell wall synthesis.
CAS RN	1194-65-6
EC number	214-787-5
CIPAC number	73
US EPA chemical code	027401
PubChem CID	3031
Molecular mass (g mol-1)	172.01
PIN (Preferred Identification Name)	2,6-dichlorobenzonitrile
IUPAC name	2,6-dichlorobenzonitrile
CAS name	2,6-dichlorobenzonitrile
Other status information	Potential groundwater contaminant; Chemical subject to PIC regulations
Relevant Environmental Water Quality Standards	-
Herbicide Resistance Classification (HRAC)	L
Herbicide Resistance Classification (WSSA)	20
Insecticide Resistance Classification (IRAC)	Not applicable
Fungicide Resistance Classification (FRAC)	Not applicable
Examples of recorded resistance	-
Physical state	White crystalline solid
Related substances & organisms	-

Can be a metabolite of:

Parent		Formation medium	Estimated maximum occurrence fraction	1107/2009 relevancy
chlorthiamid		Soil		-

Formulations:

Property	Value
Example manufacturers & suppliers of products using this active now or historically	Certis Luxan Nufarm Scotts Shell Duphar
Example products using this active	Dichlobenil Granules Casoron G Osorno Norosac
UK LERAP status	None
Formulation and application details	Often supplied as granules applied directly to the soil by mechanical spreaders or by hand.

ENVIRONMENTAL FATE
for dichlobenil

Property		Value	Source/Quality Score/Other Information	Interpretation
Solubility - In water at 20oC (mg l-1)		21.2	A5 - @ 25 DegC	Low
Solubility - In organic solvents at 20oC (mg l-1)		86000	A5 - Acetone	-
		53000	A5 - Xylene	-
		3700	A5 - Cyclohexane	-
		151000	A5 - Dichloromethane	-
Melting point (oC)		144.5	A5	-
Boiling point (oC)		Decomposes before boiling	A5	-
Degradation point (oC)		120	A5	-
Flashpoint (oC)		Not expected to self ignite; Not highly flammable	A5	-
Octanol-water partition coefficient at pH 7, 20oC	P	5.01 X 1002	Calculated	-
	Log P	2.7	A5	Moderate
Bulk density (g ml-1)/Specific gravity		1.40	Q2	-
Dissociation constant (pKa) at 25oC		Not applicable	A5	-
		Note: No dissociation
Vapour pressure at 20oC (mPa)		0.00014	A5	Low volatility
Henry's law constant at 25oC (Pa m3 mol-1)		1.317	A5	Moderately volatile
GUS leaching potential index		2.25	Calculated	Transition state
SCI-GROW groundwater index (μg l-1) for a 1 kg ha-1 or 1 l ha-1 application rate	Value	9.41 X 10-02	Calculated	-
	Note	-
Potential for particle bound transport index		-	Calculated	Medium
Maximum UV-vis absorption L mol-1 cm-1		298.9nm = 1985.3; [290nm = 1878.8; [243nm = 5766.9; [236.9nm = 6805.9; [211nm = 38528.8	A5	-
Surface tension (mN m-1)		68.5	A5 at 20oC	-

Degradation:

Property		Value	Source/Quality Score/Other Information	Interpretation
General biodegradability		-
Soil degradation (days) (aerobic)	DT50 (typical)	70	K4	Moderately persistent
	DT50 (lab at 20oC)	24.15	A5	Non-persistent
	DT50 (field)	5.4	A5	Non-persistent
	DT90 (lab at 20oC)	114.5	A5	-
	DT90 (field)	39	A5	-
	DT50 modelling endpoint	-	-	-
	Note	EU dossier Lab studies DT50 range 21.98-26.26 days, DT90 range 129-145 days; Field studies DT50 range 3.4-72 days, DT90 range 104.6-122.56 days; Other sources: DT50 1-6 months (general literature); 60 days (DW4)
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	15.1	A5	Slow
	Note	Natural light
Aqueous hydrolysis DT50 (days) at 20oC and pH 7	Value	Stable	A5	-
	Note	Stable pH 6.8 to 8.3, Rapidly hydrolysed in strong acidic media.
Water-sediment DT50 (days)		142	A5	Slow
Water phase only DT50 (days)		10.5	A5	Moderately fast

Soil adsorption and mobility:

Property		Value	Source/Quality Score/Other Information	Interpretation
Linear	Kd	-	Q3	Moderately mobile
	Koc	257
	Notes and range	Other sources: 45-400 mL/g
Freundlich	Kf	6.4	A5	Moderately mobile
	Kfoc	237
	1/n	0.844
	Notes and range	EU dossier Kf range 0.3-10.5 mL/g, Kfoc range 133-322 mL/g, 1/n 0.75-1.02, Soils=5
pH sensitivity		No

Key metabolites:

Metabolite		Formation medium	Estimated maximum occurrence fraction	1107/2009 relevancy
2,6-dichlorobenzamide (Ref: AE C653711)		Soil	0.694	Major fraction
2,6-dichlorobenzoic acid		Soil	0.660	Major fraction
O-chlorobenzamide (Ref: OBAM)		Soil	-	-

Other known metabolites:

Metabolite name and reference	Aliases	Formation medium / Rate	Estimated maximum occurrence fraction	Metabolising enzymes
4-chloro-2(3H)benzoxazolone	-	Surface water	0.0913	-
2-chlorobenozoic acid	-	Surface water	0.17	-

ECOTOXICOLOGY
for dichlobenil

Property		Value	Source/Quality Score/Other Information	Interpretation
Bio-concentration factor	BCF (l kg-1)	100	A5	Threshold for concern
	CT50 (days)	1.0		-
Mammals - Acute oral LD50 (mg kg-1)		> 2000	A5 Rat	Low
Mammals - Short term dietary NOEL	(mg kg-1)	-	L2 Rat, 2 year	-
	(ppm diet)	50		-
Birds - Acute LD50 (mg kg-1)		698	A5 Colinus virginianus	Moderate
Birds - Short term dietary (LC50/LD50)		> 5200 mg kg feed-1	A5 Colinus virginianus	-
Fish - Acute 96 hour LC50 (mg l-1)		7.2	A5 Oncorhynchus mykiss	Moderate
Fish - Chronic 21 day NOEC (mg l-1)		0.66	A5 Oncorhynchus mykiss	Moderate
Aquatic invertebrates - Acute 48 hour EC50 (mg l-1)		6.2	A5 Daphnia magna	Moderate
Aquatic invertebrates - Chronic 21 day NOEC (mg l-1)		1.2	A5 Daphnia magna	Moderate
Aquatic crustaceans - Acute 96 hour LC50 (mg l-1)		1.74	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)		0.0279	A5 Lemna gibba	Moderate
Non-target plants		-	-	-
		-	-	-
Algae - Acute 72 hour EC50, growth (mg l-1)		111	A5 Pseudokirchneriella subcapitata	Low
Algae - Chronic 96 hour NOEC, growth (mg l-1)		-	-	-
Honeybees	Contact acute 48 hour LD50 (μg bee-1)	11	L3	Moderate
	Oral acute 48 hour LD50 (μg bee-1)	-	-	-
	Unknown mode acute 48 hour LD50 (μg bee-1)	-	-	-
Earthworms - Acute 14 day LC50 (mg kg-1)		135	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	33.8	A5 Folsomia candida, NOEC, 28 day	-
Other arthropod (1)	LR50 g ha-1	-	-	-
	% Effect	-	-	-
Other arthropod (2)	LR50 g ha-1	-	-	-
	% Effect	-	-	-
Soil micro-organisms		-	-	-
Mesocosm study data	NOEAEC mg l-1	-	-	-
	NOEAEC mg l-1	-	-	-

HUMAN HEALTH AND PROTECTION
for dichlobenil

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)		> 2000	A5 Rat	Low
Mammals - Dermal LD50 (mg kg-1 body weight)		> 2000	A5 Rat	-
Mammals - Inhalation LC50 (mg l-1)		0.25	L3 Rat	-
Other Mammal toxicity endpoints		-		-
ADI - Acceptable Daily Intake (mg kg-1bw day-1)		0.01	A4 proposed Dog, SF=100	-
ARfD - Acute Reference Dose (mg kg-1bw day-1)		0.45	A4 proposed 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)		0.01	A4 proposed Dog, SF=100	-
Dermal penetration studies (%)		1.4	A3	-
Dangerous Substances Directive 76/464		-	-	-
Exposure Limits		-	-	-
Exposure Routes	Public	Negligible risks for the prescribed applications
	Occupational	Acceptable risks for the prescribed applications
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		Possible liver, kidney, stomach and parathyroid toxicant May cause dermatitis Chronic exposure may cause sedation, lose of appetite and severe respiratory problems USEPA - possible human carcinogen

: 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 or oxidising IMDG Transport Code is usually 9
CLP classification 2013		Health: H302 Environment: H411
EC Risk Classification		Xn - Harmful: R21 N - Dangerous for the environment: R51, R53
EC Safety Classification		S2, S36/37, S61
WHO Classification		III	-	Slightly hazardous
US EPA Classification (formulation)		III	-	Caution - Slightly toxic
UN Number		Usually 3077
Waste disposal & packaging		Packaging Group III (minor danger)

TRANSLATIONS
for dichlobenil

Language	Name
English	dichlobenil
French	dichlobenil
German	Dichlobenil
Danish	diclobenil
Italian	diclobenil
Spanish	diclobenil
Greek	dichlobenil
Slovenian	diklobenil
Polish	dichlobenyl
Swedish	-
Hungarian	dichlobenil
Dutch	dichlobenil

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Record last updated: Tuesday 22 May 2018
Contact: aeru@herts.ac.uk