Bensulfuron (Ref: IN-R9419)	Last updated: 12/01/2021
(Also known as: free acid bensulfuron-methyl)

---

SUMMARY

Bensulfuron is a herbicide normally used as the methyl variant. It is not expected to be persistent in soil and as it is considered moderately mobile there are some risks of leaching to groundwater. Based on bensulfurons physico-chemical properties there may also be a risk of bio-concentration. Its is moderately toxic to aquatic plants and to earthworms.

GENERAL INFORMATION

Description	A pyrimidinylsulfonylurea herbicide used to control annual and perennial weeds and sedges. Usually used as the methyl variant. Pesticide transformation product.
Example pests controlled	Pigweed; Chickweed; Wild mustard; Stinkgrass; Barnyardgrass; Rice flatsedge; Dwarf umbrella grass; Nut-grass; Creeping water primrose
Example applications	Cereals especially wheat; Rice
Efficacy & activity	-
Availability status	Current
Introduction & key dates	1985

UK regulatory status

UK COPR regulatory status	Not approved
Date COPR inclusion expires	Not applicable
UK LERAP status	No UK approval for use

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status	Approved
Dossier rapporteur/co-rapporteur	Italy/Spain
Date EC 1107/2009 inclusion expires	31/10/2022
EU Candidate for substitution (CfS)	No
Listed in EU database	Yes
Approved for use (✓) under EC 1107/2009 in the following EU Member States	ATAustria BEBelgium BGBulgaria CYCyprus CZCzech Republic DEGermany DKDenmark EEEstonia ELGreece                   ESSpain FIFinland FRFrance HRCroatia HUHungary IEIreland ITItaly LTLithuania LULuxembourg ✓   ✓ ✓ ✓   ✓     LVLatvia MTMalta NLNetherlands PLPoland PTPortugal RORomania SESweden SISlovenia SKSlovakia         ✓ ✓

Also used in

Also used in	-

Chemical structure

Isomerism	-
Chemical formula	C₁₅H₁₆N₄O₇S
Canonical SMILES	COC1=CC(=NC(=N1)NC(=O)NS(=O)(=O)CC2=CC=CC=C2C(=O)O)OC
Isomeric SMILES	No data
International Chemical Identifier key (InChIKey)	PPWBRCCBKOWDNB-UHFFFAOYSA-N
International Chemical Identifier (InChI)	InChI=1S/C15H16N4O7S/c1-25-11-7-12(26-2)17-14(16-11)18-15(22)19-27(23,24)8-9-5-3-4-6-10(9)13(20)21/h3-7H,8H2,1-2H3,(H,20,21)(H2,16,17,18,19,22)
2D structure diagram/image available?	Yes

General status

Pesticide type	Herbicide, Metabolite
Metabolite Type	Soil
Substance group	Sulfonylurea
Minimum active substance purity	-
Known relevant impurities	EU dossier - None declared
Substance origin	Synthetic
Mode of action	Selective, systemic action being absorbed through foliage and roots. Inhibits plant amino acid synthesis - acetohydroxyacid synthase AHAS
CAS RN	99283-01-9
EC number	-
CIPAC number	502
US EPA chemical code	-
PubChem CID	107828
Molecular mass	396.38
PIN (Preferred Identification Name)	2-({[(4,6-dimethoxypyrimidin-2-yl)carbamoyl]sulfamoyl}methyl)benzoic acid
IUPAC name	α-[(4,6-dimethoxypyrimidin-2-ylcarbamoyl)sulfamoyl]-o-toluic acid
CAS name	2-[[[[[(4,6-dimethoxy-2-pyrimidinyl)amino]carbonyl]amino]sulfonyl]methyl]benzoic acid
Other status information	-
Relevant Environmental Water Quality Standards	-
Herbicide Resistance Classification (HRAC)	B
Herbicide Resistance Classification (WSSA)	2
Insecticide Resistance Classification (IRAC)	Not applicable
Fungicide Resistance Classification (FRAC)	Not applicable
Examples of recorded resistance	-
Physical state	-
Related substances & organisms	bensulfuron-methyl

Formulations

Property	Value
Example manufacturers & suppliers of products using this active now or historically	-
Example products using this active	DuPont
Formulation and application details	Usually formulated as the methyl variant

ENVIRONMENTAL FATE

Property		Value	Source; quality score; and other information	Interpretation
Solubility - In water at 20 °C (mg l⁻¹)		-	-	-
Solubility - In organic solvents at 20 °C (mg l⁻¹)		-	-	-
Melting point (°C)		-	-	-
Boiling point (°C)		-	-	-
Degradation point (°C)		-	-	-
Flashpoint (°C)		-	-	-
Octanol-water partition coefficient at pH 7, 20 °C	P	1.20 X 1002	Calculated	-
	Log P	2.08	Q2 Q = Miscellaneous internet resources 2 = Unverified data of unknown source	Low
Bulk density (g ml⁻¹)		1.52	Q2 Q = Miscellaneous internet resources 2 = Unverified data of unknown source	-
Dissociation constant pKa) at 25 °C		-	-	-
		-
Vapour pressure at 20 °C (mPa)		-	-	-
Henry's law constant at 25 °C (Pa m³ mol⁻¹)		-	-	-
Maximum UV-vis absorption L mol⁻¹ cm⁻¹		-	-	-
Surface tension (mN m⁻¹)		-	-	-

Degradation

Property		Value	Source; quality score; and other information	Interpretation
General biodegradability		-
Soil degradation (days) (aerobic)	DT₅₀ (typical)	11	A5 A = EU regulatory and evaluation data as published by EC, EFSA (RAR, DAR & Conclusion dossiers), EMA (e.g. EU Annex III PIC DGD) (EU - Pesticides database; EFSA Scientific Publications ) 5 = Verified data used for regulatory purposes	Non-persistent
	DT₅₀ (lab at 20 °C)	26.2	A5 A = EU regulatory and evaluation data as published by EC, EFSA (RAR, DAR & Conclusion dossiers), EMA (e.g. EU Annex III PIC DGD) (EU - Pesticides database; EFSA Scientific Publications ) 5 = Verified data used for regulatory purposes	Non-persistent
	DT₅₀ (field)	-	-	-
	DT₉₀ (lab at 20 °C)	86.6	A5 A = EU regulatory and evaluation data as published by EC, EFSA (RAR, DAR & Conclusion dossiers), EMA (e.g. EU Annex III PIC DGD) (EU - Pesticides database; EFSA Scientific Publications ) 5 = Verified data used for regulatory purposes	Moderately persistent
	DT₉₀ (field)	-	-	-
	DT₅₀ modelling endpoint	-	-	-
	Note	EU dossier lab studies DT₅₀ range 8-54 days, DT₉₀ range 27-15 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	-	-	-
	Note	-
Aqueous hydrolysis DT₅₀ (days) at 20 °C and pH 7	Value	-	-	-
	Note	-
Water-sediment DT₅₀ (days)		5.2	A5 A = EU regulatory and evaluation data as published by EC, EFSA (RAR, DAR & Conclusion dossiers), EMA (e.g. EU Annex III PIC DGD) (EU - Pesticides database; EFSA Scientific Publications ) 5 = Verified data used for regulatory purposes	Fast
Water phase only DT₅₀ (days)		8.0	A5 A = EU regulatory and evaluation data as published by EC, EFSA (RAR, DAR & Conclusion dossiers), EMA (e.g. EU Annex III PIC DGD) (EU - Pesticides database; EFSA Scientific Publications ) 5 = Verified data used for regulatory purposes	Moderately fast

Soil adsorption and mobility

Property		Value	Source; quality score; and other information	Interpretation
Linear	Kd	-	-	-
	Koc	-
	Notes and range	-
Freundlich	Kf	8.8	A5 A = EU regulatory and evaluation data as published by EC, EFSA (RAR, DAR & Conclusion dossiers), EMA (e.g. EU Annex III PIC DGD) (EU - Pesticides database; EFSA Scientific Publications ) 5 = Verified data used for regulatory purposes	Moderately mobile
	Kfoc	226
	1/n	0.9
	Notes and range	EU dossier Kf range 0.3-17.4 mL g⁻¹, Kfoc range 28-580 mL g⁻¹, 1/n range 0.89-0.93, Soils=5
pH sensitivity		No

Fate indices

Property		Value	Source; quality score; and other information	Interpretation
GUS leaching potential index		2.33	Calculated	Transition state
SCI-GROW groundwater index (μg l⁻¹) for a 1 kg ha⁻¹ or 1 l ha⁻¹ application rate	Value	1.08 X 10-01	Calculated	-
	Note	-
Potential for particle bound transport index		-	-	-
Potential for loss via drain flow		-	-	-

Key metabolites

Metabolite	Formation medium	Estimated maximum occurrence fraction	1107/2009 relevancy
2-((aminosulfonyl)methyl)benzoic acid (Ref: IN-D1R84)	Soil	0.182	Major fraction, Relevant
2-amino-4,6-dimethoxypyrimidine (Ref: AE-F092944)	Soil	0.460	Major fraction, Relevant

ECOTOXICOLOGY

Property		Value	Source; quality score; and other information	Interpretation
Bio-concentration factor	BCF (l kg⁻¹)	Low risk	Q3 Q = Miscellaneous internet resources 3 = Unverified data of known source Based on LogP < 3	Low risk
	CT₅₀ (days)	-		-
Mammals - Acute oral LD₅₀ (mg kg⁻¹)		-	-	-
Mammals - Short term dietary NOEL	(mg kg⁻¹)	-	-	-
	(ppm diet)	-		-
Mammals - Chronic 21d NOAEL (mg kg⁻¹ bw d⁻¹)		-	-	-
Birds - Acute LD₅₀ (mg kg⁻¹)		-	-	-
Birds - Short term dietary (LC₅₀/LD₅₀)		-	-	-
Birds - Chronic 21d NOEL (mg kg⁻¹ bw d⁻¹)		-	-	-
Fish - Acute 96 hour LC₅₀ (mg l⁻¹)		-	-	-
Fish - Chronic 21 day NOEC (mg l⁻¹)		-	-	-
Aquatic invertebrates - Acute 48 hour EC₅₀ (mg l⁻¹)		-	-	-
Aquatic invertebrates - Chronic 21 day NOEC (mg l⁻¹)		-	-	-
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)		6.2	A5 A = EU regulatory and evaluation data as published by EC, EFSA (RAR, DAR & Conclusion dossiers), EMA (e.g. EU Annex III PIC DGD) (EU - Pesticides database; EFSA Scientific Publications ) 5 = Verified data used for regulatory purposes Lemna gibba	Moderate
Non-target plants		-	-	-
		-	-	-
Algae - Acute 72 hour EC₅₀, growth (mg l⁻¹)		26.4	A5 A = EU regulatory and evaluation data as published by EC, EFSA (RAR, DAR & Conclusion dossiers), EMA (e.g. EU Annex III PIC DGD) (EU - Pesticides database; EFSA Scientific Publications ) 5 = Verified data used for regulatory purposes Pseudokirchneriella subcapitata	Low
Algae - Chronic 96 hour NOEC, growth (mg l⁻¹)		-	-	-
Honeybees (Apis spp.)	Contact acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)	-	-	-
	Oral acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)	-	-	-
	Unknown mode acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)	-	-	-
Bumblebees (Bombus spp.)	Contact acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)	-	-	-
		-
	Oral acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)	-	-	-
		-
Mason bees (Osmia spp.)	Contact acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)	-	-	-
	Oral acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)	-	-	-
Other pollinators (1)	Acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg insect⁻¹)	-	-	-
	Mode of exposure	-
Other pollinators (2)	Acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg insect⁻¹)	-	-	-
	Mode of exposure	-
Earthworms - Acute 14 day LC₅₀ (mg kg⁻¹)		> 1000	A5 A = EU regulatory and evaluation data as published by EC, EFSA (RAR, DAR & Conclusion dossiers), EMA (e.g. EU Annex III PIC DGD) (EU - Pesticides database; EFSA Scientific Publications ) 5 = Verified data used for regulatory purposes Eisenia foetida	Low
Earthworms - Chronic NOEC, reproduction (mg kg⁻¹)		-	-	-
Other soil macro-organisms	Acute LC₅₀ (mg kg⁻¹)	-	-	-
	Chronic NOEC (mg kg⁻¹)	-	-	-
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

General

Property		Value	Source; quality score; and other information	Interpretation
Threshold of Toxicological Concern (Cramer Class)		High (class III)	-	-
Mammals - Acute oral LD₅₀ (mg kg⁻¹)		-	-	-
Mammals - Dermal LD₅₀ (mg kg⁻¹ body weight)		-	-	-
Mammals - Inhalation LC₅₀ (mg l⁻¹)		-	-	-
Other Mammal toxicity endpoints		-	-	-
ADI - Acceptable Daily Intake (mg kg⁻¹ bw day⁻¹)		0.2	A5 A = EU regulatory and evaluation data as published by EC, EFSA (RAR, DAR & Conclusion dossiers), EMA (e.g. EU Annex III PIC DGD) (EU - Pesticides database; EFSA Scientific Publications ) 5 = Verified data used for regulatory purposes	-
ARfD - Acute Reference Dose (mg kg⁻¹ bw day⁻¹)		None allocated	A5 A = EU regulatory and evaluation data as published by EC, EFSA (RAR, DAR & Conclusion dossiers), EMA (e.g. EU Annex III PIC DGD) (EU - Pesticides database; EFSA Scientific Publications ) 5 = Verified data used for regulatory purposes	-
AAOEL - Acute Acceptable Operator Exposure Level (mg kg⁻¹ bw day⁻¹)		-	-	-
AOEL - Acceptable Operator Exposure Level - Systemic (mg kg⁻¹ bw day⁻¹)		0.12	A5 A = EU regulatory and evaluation data as published by EC, EFSA (RAR, DAR & Conclusion dossiers), EMA (e.g. EU Annex III PIC DGD) (EU - Pesticides database; EFSA Scientific Publications ) 5 = Verified data used for regulatory purposes	-
Dermal penetration studies (%)		-	-	-
Dangerous Substances Directive 76/464		-	-	-
Exposure Routes	Public	-
	Occupational	-
MRLs	European	EU MRL pesticide database
	Notes	-
Drinking Water Standards		-	-	-
Drinking Water MAC (μg l⁻¹)		-	-	-

Health issues

Specific human health issues		Carcinogen Genotoxic Endocrine disruptor XNo, known not to cause a problem A0 A = Chromosome aberration (EFSA database) 0 = No data ; B0 B = DNA damage/repair (EFSA database) 0 = No data ; C0 C = Gene mutation (EFSA database) 0 = No data ; D0 D = Genome mutation (EFSA database) 0 = No data ; E0 E = Unspecified genotoxicity type (miscellaneous data source) 0 = No data XNo, known not to cause a problem Reproduction / development effects Acetyl cholinesterase inhibitor Neurotoxicant ?Possibly, status not identified No data found No data found Respiratory tract irritant Skin irritant Skin sensitiser No data found XNo, known not to cause a problem ?Possibly, status not identified Eye irritant Phototoxicant   XNo, known not to cause a problem No data found
General human health issues		Possible liver toxicant

Handling issues

Property	Value and interpretation
General	Not explosive or oxidising
CLP classification 2013	-
EC Risk Classification	Reproduction risk category 3: R63 Xn - Harmful: R43 N - Dangerous for the environment: R50, R53
EC Safety Classification	S35, S57, S60, S61
WHO Classification	U (Unlikely to present an acute hazard)
UN Number	-
Waste disposal & packaging	-

TRANSLATIONS

Language	Name
English	bensulfuron
French	bensulfuron
German	Bensulfuron
Danish	bensulfuron
Italian	bensulfuron
Spanish	bensulfuron
Greek	-
Polish	bensulfuron
Swedish	-
Hungarian	benszulforon
Dutch	-

---

Record last updated:	12/01/2021
Contact:	aeru@herts.ac.uk
Please cite as:	Lewis, K.A., Tzilivakis, J., Warner, D. and Green, A. (2016) An international database for pesticide risk assessments and management. Human and Ecological Risk Assessment: An International Journal, 22(4), 1050-1064. DOI: 10.1080/10807039.2015.1133242