Fomesafen (Ref: PP 021)	Last updated: 23/01/2023
(Also known as: fomesafene; fomesafen acid)

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SUMMARY

Fomesafen is a selective herbicide. It is moderately soluble in aqueous solution, is relatively volatile but does have potential to leach to groundwater. It is persistent in soils and aquatic systems. It is moderately toxic to mammals and although a recognised irritant no other significant health issues have been identified. It is not toxic to birds or fish but considered moderately toxic to aquatic crustaceans, honeybees and earthworms.

Data alerts

The following alerts are based on the data in the tables below. An absence of an alert does not imply the substance has no implications for human health, biodiversity or the environment but just that we do not have the data to form a judgement.

Environmental fate	Ecotoxicity	Human health
Environmental fate High alert: GUS: High leachability; Drainflow: Mobile	Ecotoxicity Moderate alert: Bees acute oral ecotoxicity: Moderate; Earthworms acute ecotoxicity: Moderate	Human health Moderate alert: Mammals acute toxicity: Moderate; Possible Reproduction/development effects

GENERAL INFORMATION

Description	A pre-emergence herbicide for use in leguminous crops for post-emergence control of broad-leaved weeds
Example pests controlled	Pigweed, Black nightshade, Velvetleaf, Cocklebur
Example applications	Legumes; Cotton; Soybeans; Potatoes; Tomatoes
Efficacy & activity	-
Availability status	Unknown
Introduction & key dates	1983, first reported

UK regulatory status

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

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status	Not approved
Dossier rapporteur/co-rapporteur	-
Date EC 1107/2009 inclusion expires	Expired
EU Candidate for substitution (CfS)	-
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

Additional information

Also used in	-

Chemical structure

Isomerism	-
Chemical formula	C₁₅H₁₀ClF₃N₂O₆S
Canonical SMILES	CS(=O)(=O)NC(=O)C1=C(C=CC(=C1)OC2=C(C=C(C=C2)C(F)(F)F)Cl)[N+](=O)[O-]
Isomeric SMILES	-
International Chemical Identifier key (InChIKey)	BGZZWXTVIYUUEY-UHFFFAOYSA-N
International Chemical Identifier (InChI)	InChI=1S/C15H10ClF3N2O6S/c1-28(25,26)20-14(22)10-7-9(3-4-12(10)21(23)24)27-13-5-2-8(6-11(13)16)15(17,18)19/h2-7H,1H3,(H,20,22)
2D structure diagram/image available?	Yes

General status

Pesticide type	Herbicide
Substance groups	Organochloride fungicide; Organofluoride fungicide; Amide fungicide; Nitrophenol etther fungicide
Minimum active substance purity	-
Known relevant impurities	-
Substance origin	Synthetic
Mode of action	Selective, absorbed by leaves and roots. Inhibits protoporphyrinogen oxidase (PROTOX), leading to irreversible cell membrane damage.
CAS RN	72178-02-0
EC number	276-439-9
CIPAC number	None allocated
US EPA chemical code	123802
PubChem CID	51556
CLP index number	604-040-00-5
Molecular mass	438.76
PIN (Preferred Identification Name)	5-(2-chloro-α,α,α-trifluoro-p-tolyloxy)-N-mesyl-2-nitrobenzamide
IUPAC name	5-(2-chloro-α,α,α-trifluoro-p-tolyloxy)-N-mesyl-2-nitrobenzamide
CAS name	5-[2-chloro-4-(trifluoromethyl)phenoxy]-N-(methylsulfonyl)-2-nitrobenzamide
Other status information	-
Relevant Environmental Water Quality Standards	-
Herbicide Resistance Classification (HRAC)	E
Herbicide Resistance Classification (WSSA)	14
Insecticide Resistance Classification (IRAC)	Not applicable
Fungicide Resistance Classification (FRAC)	Not applicable
Examples of recorded resistance	Amaranthus rudis, Euphorbia heterophylla
Physical state	White crystals
Related substances & organisms	fomesafen-sodium

Formulations

Property	Value
Example manufacturers & suppliers of products using this active now or historically	FCC Ltd King Tech AgroCare ICI Plant Protection
Example products using this active	Eagrow Reflex Flexstar Format
Formulation and application details	Usually supplied as an soluble concentrate or liquid concentratate.

ENVIRONMENTAL FATE

Property		Value	Source; quality score; and other information	Interpretation
Solubility - In water at 20 °C (mg l⁻¹)		50	B5 B = UK CRD and ACP evaluation documents / and other Defra (UK) documents (click here ) 5 = Verified data used for regulatory purposes	Moderate
Solubility - In organic solvents at 20 °C (mg l⁻¹)		300000	C4 C = AGRITOX (click here ) 4 = Verified data Acetone	-
		25000	C4 C = AGRITOX (click here ) 4 = Verified data Methanol	-
		1900	C4 C = AGRITOX (click here ) 4 = Verified data Xylene	-
		10000	C4 C = AGRITOX (click here ) 4 = Verified data Dichloromethane	-
Melting point (°C)		219	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source	-
Boiling point (°C)		-	-	-
Degradation point (°C)		-	-	-
Flashpoint (°C)		-	-	-
Octanol-water partition coefficient at pH 7, 20 °C	P	6.31 X 10-02	Calculated	-
	Log P	-1.2	B5 B = UK CRD and ACP evaluation documents / and other Defra (UK) documents (click here ) 5 = Verified data used for regulatory purposes	Low
Fat solubility of residues	Solubility	Likely to be soluble	Q3 Q = Miscellaneous internet resources 3 = Unverified data of known source	-
	Data type	Based on chemical group	Q3 Q = Miscellaneous internet resources 3 = Unverified data of known source	-
Density (g ml⁻¹)		1.61	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source	-
Dissociation constant pKa) at 25 °C		2.83	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source	-
		Forms water soluble salts, strong acid
Vapour pressure at 20 °C (mPa)		4.00 X 10-03	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source	Low volatility
Henry's law constant at 25 °C (Pa m³ mol⁻¹)		2.00 X 10-07	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source	Non-volatile
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)	86	B5 B = UK CRD and ACP evaluation documents / and other Defra (UK) documents (click here ) 5 = Verified data used for regulatory purposes	Moderately persistent
	DT₅₀ (lab at 20 °C)	-	-	-
	DT₅₀ (field)	86	B5 B = UK CRD and ACP evaluation documents / and other Defra (UK) documents (click here ) 5 = Verified data used for regulatory purposes	Moderately persistent
	DT₉₀ (lab at 20 °C)	-	-	-
	DT₉₀ (field)	-	-	-
	DT₅₀ modelling endpoint	-	-	-
	Note	Field studies DT₅₀ range 59-112 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	Stable	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source	Stable
	Note	-
Aqueous hydrolysis DT₅₀ (days) at 20 °C and pH 7	Value	-	-	-
	Note	-
Water-sediment DT₅₀ (days)		7	B5 B = UK CRD and ACP evaluation documents / and other Defra (UK) documents (click here ) 5 = Verified data used for regulatory purposes	Fast
Water phase only DT₅₀ (days)		-	-	-

Soil adsorption and mobility

Property		Value	Source; quality score; and other information	Interpretation
Linear	Kd	-	B4 B = UK CRD and ACP evaluation documents / and other Defra (UK) documents (click here ) 4 = Verified data	Mobile
	Koc	50
	Notes and range	Literature studies state Koc range 150-1200 (R3)
Freundlich	Kf	1.89	R4 R = Peer reviewed scientific publications 4 = Verified data	Moderately mobile
	Kfoc	228
	1/n	0.77
	Notes and range	Literature data: Kf range 1.38-3.02 mL g⁻¹, Kfoc range 115-348 mL g⁻¹, 1/n range 0.65-0.83, soils=6
pH sensitivity		R4

Fate indices

Property		Value	Source; quality score; and other information	Interpretation
GUS leaching potential index		3.18	Calculated	High leachability
SCI-GROW groundwater index (μg l⁻¹) for a 1 kg ha⁻¹ or 1 l ha⁻¹ application rate	Value	4.08 X 10-01	Calculated	-
	Note	-
Potential for particle bound transport index		Medium	Calculated	-
Potential for loss via drain flow		Mobile	Calculated	-
Bio-concentration factor	BCF (l kg⁻¹)	6	F4 F = U.S. EPA ECOTOX database / U.S. EPA pesticide fate database / Miscellaneous WHO documents (US EPA Databases Related to Pesticide Risk Assessment ) 4 = Verified data Whole fish	Low potential
	CT₅₀ (days)	Not available		-

Known metabolites

None

ECOTOXICOLOGY

Terrestrial ecotoxicology

Property		Value	Source; quality score; and other information	Interpretation
Mammals - Acute oral LD₅₀ (mg kg⁻¹)		1250	B5 B = UK CRD and ACP evaluation documents / and other Defra (UK) documents (click here ) 5 = Verified data used for regulatory purposes Rat	Moderate
Mammals - Short term dietary NOEL	(mg kg⁻¹)	0.25	B5 B = UK CRD and ACP evaluation documents / and other Defra (UK) documents (click here ) 5 = Verified data used for regulatory purposes Rat	High
	(ppm diet)	5		-
Mammals - Chronic 21d NOAEL (mg kg⁻¹ bw d⁻¹)		-	-	-
Birds - Acute LD₅₀ (mg kg⁻¹)		> 5000	B5 B = UK CRD and ACP evaluation documents / and other Defra (UK) documents (click here ) 5 = Verified data used for regulatory purposes Anas platyrhynchos	Low
Birds - Short term dietary (LC₅₀/LD₅₀)		-	-	-
Birds - Chronic 21d NOEL (mg kg⁻¹ bw d⁻¹)		-	-	-
Earthworms - Acute 14 day LC₅₀ (mg kg⁻¹)		1000	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source	Moderate
Earthworms - Chronic NOEC, reproduction (mg kg⁻¹)		-	-	-
Soil micro-organisms		-	-	-
Collembola	Acute LC₅₀ (mg kg⁻¹)	-	-	-
	Chronic NOEC (mg kg⁻¹)	-	-	-
Non-target plants		-	-	-
		-	-	-
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)	50	B5 B = UK CRD and ACP evaluation documents / and other Defra (UK) documents (click here ) 5 = Verified data used for regulatory purposes	Moderate
	Unknown mode acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)	-	-	-
	Chronic	-	-	-
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	-
Beneficial insects (Ladybirds)		-	-	-
Beneficial insects (Lacewings)		-	-	-
Beneficial insects (Parasitic wasps)		-	-	-
Beneficial insects (Predatory mites)		-	-	-
Beneficial insects (Ground beetles)		-	-	-

Aquatic ecotoxicology

Property		Value	Source; quality score; and other information	Interpretation
Fish - Acute 96 hour LC₅₀ (mg l⁻¹)		> 170	B5 B = UK CRD and ACP evaluation documents / and other Defra (UK) documents (click here ) 5 = Verified data used for regulatory purposes Oncorhynchus mykiss	Low
Fish - Chronic 21 day NOEC (mg l⁻¹)		-	-	-
Aquatic invertebrates - Acute 48 hour EC₅₀ (mg l⁻¹)		> 330	B5 B = UK CRD and ACP evaluation documents / and other Defra (UK) documents (click here ) 5 = Verified data used for regulatory purposes Daphnia magna	Low
Aquatic invertebrates - Chronic 21 day NOEC (mg l⁻¹)		> 100	F3 F = U.S. EPA ECOTOX database / U.S. EPA pesticide fate database / Miscellaneous WHO documents (US EPA Databases Related to Pesticide Risk Assessment ) 3 = Unverified data of known source Daphnia magna LOEC	Low
Aquatic crustaceans - Acute 96 hour LC₅₀ (mg l⁻¹)		22.1	F3 F = U.S. EPA ECOTOX database / U.S. EPA pesticide fate database / Miscellaneous WHO documents (US EPA Databases Related to Pesticide Risk Assessment ) 3 = Unverified data of known source 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)		-	-	-
Algae - Acute 72 hour EC₅₀, growth (mg l⁻¹)		0.17	L2 L = Pesticide manuals and hard copy reference books / other sources 2 = Unverified data of unknown source Unknown species	Moderate
Algae - Chronic 96 hour NOEC, growth (mg l⁻¹)		-	-	-
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)		1250	B5 B = UK CRD and ACP evaluation documents / and other Defra (UK) documents (click here ) 5 = Verified data used for regulatory purposes Rat	Moderate
Mammals - Dermal LD₅₀ (mg kg⁻¹ body weight)		1000	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source Rabbit	-
Mammals - Inhalation LC₅₀ (mg l⁻¹)		> 4.97	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source Rat	-
Other Mammal toxicity endpoints		-	-	-
ADI - Acceptable Daily Intake (mg kg⁻¹ bw day⁻¹)		0.003	B4 B = UK CRD and ACP evaluation documents / and other Defra (UK) documents (click here ) 4 = Verified data UK ACP 1999	-
ARfD - Acute Reference Dose (mg kg⁻¹ bw day⁻¹)		-	-	-
AAOEL - Acute Acceptable Operator Exposure Level (mg kg⁻¹ bw day⁻¹)		-	-	-
AOEL - Acceptable Operator Exposure Level - Systemic (mg kg⁻¹ bw day⁻¹)		-	-	-
Dermal penetration studies (%)		-	-	-
Dangerous Substances Directive 76/464		List I	-	-
Exposure Routes	Public	-
	Occupational	Occupational exposure may occur through inhalation of spray mists and aerosols and dermal contact
MRLs	European	EU MRL pesticide database
	Great Britain	GB MRL Register
	Notes	-
Drinking Water Standards		-	-	-
Drinking Water MAC (μg l⁻¹)		-	-	-
Mammalian dose elimination route and rate		-	-	-

Health issues

Specific human health issues		Carcinogen Genotoxic Endocrine disruptor XNo, known not to cause a problem A3 A = Chromosome aberration (EFSA database) 3 = Negative ; B3 B = DNA damage/repair (EFSA database) 3 = Negative ; C3 C = Gene mutation (EFSA database) 3 = Negative ; D0 D = Genome mutation (EFSA database) 0 = No data ; E0 E = Unspecified genotoxicity type (miscellaneous data source) 0 = No data No data found Reproduction / development effects Acetyl cholinesterase inhibitor Neurotoxicant ?Possibly, status not identified XNo, known not to cause a problem XNo, known not to cause a problem Respiratory tract irritant Skin irritant Skin sensitiser ✓Yes, known to cause a problem ✓Yes, known to cause a problem ?Possibly, status not identified Eye irritant Phototoxicant   ✓Yes, known to cause a problem No data found
General human health issues		Probably liver toxicant

Handling issues

Property	Value and interpretation
General	No information available
CLP classification 2013	Health: H302
WHO Classification	II (Moderately hazardous)
UN Number	-
Waste disposal & packaging	-

TRANSLATIONS

Language	Name
English	fomesafen
French	fomesafen
German	Fomesafen
Danish	fomesafen
Italian	fomosafen
Spanish	fomesafen
Greek	-
Polish	fomesafen
Swedish	-
Hungarian	fomezafen
Dutch	-

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Record last updated:	23/01/2023
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