bentazone ** bendioxide ** bentazon ** Translations

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SUMMARY

Bentazone is a herbicide approved for use in the EU. It is highly soluble in water, volatile and, as it is mobile, may present a risk of leaching to groundwater. It is not likely tyo be persistent in soil systems but may be persistent in water under certain conditions. It is moderately toxic to humans and a recognised skin and eye irritant. Bentazone is also moderately toxic to birds, fish, aquatic invertebrates and earthworms.

GENERAL INFORMATION
for bentazone

Description: A post-emergence contact diazinone herbicide used to control annual weeds in a variety of crops

Example pests controlled: Black bindweed; Nightshade; Fat hen; Hedge mustard; Shepherd's purse; Wild radish; Wild turnip; Bellvine; Starburr; Anoda weed

Example applications: Corn; Rice; Alfalfa; Sorghum; Linseed; Peanuts; Beans; Peas; Clover; Chives; Garlic; Ornamentals e.g. begonia; Soybeans; Turf

Efficacy & activity: -

Availability status: Current

Introduction & key dates: 1972, first introduced

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

Status	Approved
Dossier rapporteur/co-rapporteur	Netherlands/Germany
Date inclusion expires	31/05/2025
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

Also used in: Australia

Chemical structure:

Isomerism	-
Chemical formula	C10H12N2O3S
Canonical SMILES	CC(C)N1C(=O)C2=CC=CC=C2NS1(=O)=O
Isomeric SMILES	No data
International Chemical Identifier key (InChIKey)	ZOMSMJKLGFBRBS-UHFFFAOYSA-N
International Chemical Identifier (InChI)	InChI=1S/C17H21NO4S4/c1-18(2)15(13-23-25(19,20)16-9-5-3-6-10-16)14-24-26(21,22)17-11-7-4-8-12-17/h3-12,15H,13-14H2,1-2H3
2D structure diagram/image available?	Yes

General status:

Pesticide type	Herbicide
Substance group	Benzothiazinone
Minimum active substance purity	960 g/kg
Known relevant impurities	EU dossier: 1,2-dichloroethane <3.0 mg/kg
Substance origin	Synthetic
Mode of action	Selective action, absorbed by foliage with very little translocation. Inhibits photosynthesis (photosystem II).
CAS RN	25057-89-0
EC number	246-585-8
CIPAC number	366
US EPA chemical code	275200
PubChem CID	2328
Molecular mass (g mol-1)	240.3
PIN (Preferred Identification Name)	3-(propan-2-yl)-1H-2?6,1,3-benzothiadiazine-2,2,4(3H)-trione
IUPAC name	3-isopropyl-1H-2,1,3-benzothiadiazin-4(3H)-one 2,2-dioxide
CAS name	3-(1-methylethyl)-1H-2,1,3-benzothiadiazin-4(3H)-one 2,2-dioxide
Other status information	Potential groundwater contaminant
Relevant Environmental Water Quality Standards	UK Environment Agency statutory standard for the protection of surface water quality and aquatic life: annual mean classification of inland waters, coastal waters & relevant territorial waters: 500 ug l-1
Herbicide Resistance Classification (HRAC)	C3
Herbicide Resistance Classification (WSSA)	6
Insecticide Resistance Classification (IRAC)	Not applicable
Fungicide Resistance Classification (FRAC)	Not applicable
Examples of recorded resistance	-
Physical state	White to yellow coloured crystals depending upon purity
Related substances & organisms	MCPA MCPB

Formulations:

Property	Value
Example manufacturers & suppliers of products using this active now or historically	AgriGuard BASF Goldengrass
Example products using this active	Basagran Zone 48 Troy 480 Herbatox Leader Laddox
UK LERAP status	None
Formulation and application details	Usually formulated as a soluble concentrate or granules, mixed with water and applied as a spray.

ENVIRONMENTAL FATE
for bentazone

Property		Value	Source/Quality Score/Other Information	Interpretation
Solubility - In water at 20oC (mg l-1)		7112	A5	High
Solubility - In organic solvents at 20oC (mg l-1)		18.0	A5 - n-Heptane	-
		21000	A5 - Toluene	-
		388000	A5 - Ethyl acetate	-
		556000	A5 - Methanol	-
Melting point (oC)		139	A5	-
Boiling point (oC)		Decomposes before boiling	A5	-
Degradation point (oC)		210	A5	-
Flashpoint (oC)		Not expected to self ignite; Not highly flammable	A5	-
Octanol-water partition coefficient at pH 7, 20oC	P	3.47 X 10-01	Calculated	-
	Log P	-0.46	A5	Low
Bulk density (g ml-1)/Specific gravity		1.41	A5	-
Dissociation constant (pKa) at 25oC		3.51	A5	-
		Note: Weak acid; pKa(2)=2.50
Vapour pressure at 20oC (mPa)		0.17	A5	Low volatility
Henry's law constant at 25oC (Pa m3 mol-1)		7.20 X 10-05	A5	Non-volatile
GUS leaching potential index		2.89	Calculated	High leachability
SCI-GROW groundwater index (μg l-1) for a 1 kg ha-1 or 1 l ha-1 application rate	Value	1.91 X 10-01	Calculated	-
	Note	-
Potential for particle bound transport index		-	Calculated	Low
Maximum UV-vis absorption L mol-1 cm-1		pH 4.4: 225nm=30854; 335nm=2987.8	-	-
Surface tension (mN m-1)		-	-	-

Degradation:

Property		Value	Source/Quality Score/Other Information	Interpretation
General biodegradability		-
Soil degradation (days) (aerobic)	DT50 (typical)	20	A5	Non-persistent
	DT50 (lab at 20oC)	20	A5	Non-persistent
	DT50 (field)	7.5	A5	Non-persistent
	DT90 (lab at 20oC)	91.2	A5	-
	DT90 (field)	31.9	A5	-
	DT50 modelling endpoint	-	-	-
	Note	EU dossier Lab studies DT50 range 8-35.0 days, DT90 range 32-149.8 days, Soils=12; field study DT50 range 3.0-31.3 days, DT90 range 12.9-87.7 days, Soils=8
Dissipation rate RL50 on plant matrix	Value	-	-	-
	Note	-
Dissipation rate RL50 on and in plant matrix	Value	1.5	R3	-
	Note	Wheat, whole plant, n=1
Aqueous photolysis DT50 (days) at pH 7	Value	4	A5	Moderately fast
	Note	DT50 122 hours at pH 5, 14 hours at pH 9
Aqueous hydrolysis DT50 (days) at 20oC and pH 7	Value	Stable	A5	-
	Note	Stable pH 5 to pH 9
Water-sediment DT50 (days)		716	A5	Stable
Water phase only DT50 (days)		80	A2	Stable

Soil adsorption and mobility:

Property		Value	Source/Quality Score/Other Information	Interpretation
Linear	Kd	0.72	A5	Mobile
	Koc	55.3
	Notes and range	EU dossier Kd range 0.22-2.99 mL/g; Koc range 13-176 mL/g, Soils=7
Freundlich	Kf	0.97	A5	Mobile
	Kfoc	59.6
	1/n	0.93
	Notes and range	EU 2015 dossier Kf range 0.02-3.06 mL/g, Kfoc range 3.0-158.0 mL/g, 1/n range 0.7-1.03, Soils=25; Literature data: Kf range 1.2-1.9 mL/g, kfoc range 37-238 mL/g, 1/n range 1.00-1.01, Soils = 13
pH sensitivity		No

Key metabolites:

Metabolite		Formation medium	Estimated maximum occurrence fraction	1107/2009 relevancy
2-amino-N-isopropylbenzamide		Soil	-	Minor fraction, Not relevant
N-methyl bentazone		Soil	0.057	Minor fraction, Relevant

Other known metabolites:

Metabolite name and reference	Aliases	Formation medium / Rate	Estimated maximum occurrence fraction	Metabolising enzymes
8-hydroxy-bentazone	-	Plant; Animal	-	-
6-hydroxy bentazone	-	Plant; Animal	-	-
3-isopropyl-4,5-dioxo-1,3,4,5,6,7-hexahydrocyclopenta[c][1,2,6]thiadiazine-6-carboxylic acid 2,2-dioxide, salts (Ref: M351H023)	Peak-B	Surface water	-	-
[2-(isopropylcarbamoyl)phenyl]sulfamic acid, salts (Ref: M351H024)	Peak-C	Surface water	-	-

ECOTOXICOLOGY
for bentazone

Property		Value	Source/Quality Score/Other Information	Interpretation
Bio-concentration factor	BCF (l kg-1)	21	A5	Low potential
	CT50 (days)	Not available		-
Mammals - Acute oral LD50 (mg kg-1)		1400	A5 Rat	Moderate
Mammals - Short term dietary NOEL	(mg kg-1)	25	L3 Rat	High
	(ppm diet)	-		-
Birds - Acute LD50 (mg kg-1)		1140	A5 Colinus virginianus	Moderate
Birds - Short term dietary (LC50/LD50)		-	-	-
Fish - Acute 96 hour LC50 (mg l-1)		> 100	A5 Oncorhynchus mykiss	Low
Fish - Chronic 21 day NOEC (mg l-1)		48	A5 Oncorhynchus mykiss	Low
Aquatic invertebrates - Acute 48 hour EC50 (mg l-1)		> 100	A5 Daphnia magna	Low
Aquatic invertebrates - Chronic 21 day NOEC (mg l-1)		> 101	A5 Daphnia magna	Low
Aquatic crustaceans - Acute 96 hour LC50 (mg l-1)		132.5	F3 Americamysis bahia	Low
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)		5.4	A5 Lemna gibba	Moderate
Non-target plants		-	-	-
		-	-	-
Algae - Acute 72 hour EC50, growth (mg l-1)		10.1	A4 Anabaena flos-aquae, 120 hour	Low
Algae - Chronic 96 hour NOEC, growth (mg l-1)		25.7	A3 Unknown species	Low
Honeybees	Contact acute 48 hour LD50 (μg bee-1)	> 200	A5	Low
	Oral acute 48 hour LD50 (μg bee-1)	> 200	A5	Low
	Unknown mode acute 48 hour LD50 (μg bee-1)	-	-	-
Earthworms - Acute 14 day LC50 (mg kg-1)		870	A5 Eisenia foetida	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	-	-	-
	% Effect	51	Parasitism Dose: 2.63 kg ha-1 A5 Trichogramma cacoeciae, adult	-
Other arthropod (2)	LR50 g ha-1	-	-	-
	% Effect	7	Mortality Dose: 1.92 Kg ha-1 A5 Typhlodromus pyri, protonymph	-
Soil micro-organisms		Nitrogen mineralisation: No significant adverse effect Carbon mineralisation: No significant adverse effect	A5 Dose: 9.6 kg ha-1	-
Mesocosm study data	NOEAEC mg l-1	-	-	-
	NOEAEC mg l-1	-	-	-

HUMAN HEALTH AND PROTECTION
for bentazone

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)		1400	A5 Rat	Moderate
Mammals - Dermal LD50 (mg kg-1 body weight)		> 5000	A5 Rat	-
Mammals - Inhalation LC50 (mg l-1)		> 5.1	A5 Rat, 4 hr (head-nose only)	-
Other Mammal toxicity endpoints		-		-
ADI - Acceptable Daily Intake (mg kg-1bw day-1)		0.1	A5	-
ARfD - Acute Reference Dose (mg kg-1bw day-1)		0.25	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)		0.13	A4 Dog, 1 year, SF=100	-
Dermal penetration studies (%)		0.2-0.9	A5 concentration dependent	-
Dangerous Substances Directive 76/464		List II	-	-
Exposure Limits		-	-	-
Exposure Routes	Public	Minimal risk of dietary exposure No unacceptable risks to bystanders identified
	Occupational	Risk of exposure acceptable under label recommendations for use for personal protection clothing and equipment
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 blood, liver, kidney toxicant

: 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 oxidising or explosive
CLP classification 2013		Health: H302, H317, H319 Environment: H412
EC Risk Classification		Xn - Harmful: R22, R43 Xi - Irritant: R36 N - Dangerous for the environment: R52, R53
EC Safety Classification		S2, S24, S37, S61
WHO Classification		II	-	Moderately hazardous
US EPA Classification (formulation)		III	-	Caution - Slightly toxic
UN Number		Usually 2588
Waste disposal & packaging		Packaging Group III (minor danger)

TRANSLATIONS
for bentazone

Language	Name
English	bentazone
French	bentazone
German	Bentazon
Danish	bentazon
Italian	bentazone
Spanish	bentazona
Greek	bentazone
Slovenian	bentazon
Polish	bentazon
Swedish	bentazon
Hungarian	bentazone
Dutch	bentazon

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Record last updated: Thursday 23 August 2018
Contact: aeru@herts.ac.uk