Bicyclopyrone (Ref: NOA449280)	Last updated: 10/10/2025
(Not known by any other names)

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SUMMARY

Bicyclopyrone is a broad-spectrum herbicide. It is highly soluble in water and non-volatile. It can be persistent in both soil and aquatic systems. It is moderately toxic to fish, aquatic invertebrates and aquatic plants but presents a low risk to honeybees. Its oral mammalian toxicity is low but there are some concerns that it may be a reproduction/developmental toxin.

Hazard 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. These hazard alerts do not take account of usage patterns or exposure, thus do not represent risk.

Environmental fate	Ecotoxicity	Human health
	Ecotoxicity Moderate alert: Fish acute ecotoxicity: Moderate; Daphnia acute ecotoxicity: Moderate Warning: Significant data are missing	Human health High alert: Mammals chronic toxicity: High; Reproduction/development effects

GENERAL INFORMATION

Description	A broad-spectrum herbicide, sometimes used in mixtures, for the pre- and post-emergence control of grass and dicot weeds mainly in corn
Example pests controlled	Foxtail; Wild buckwheat; Common ragweed
Example applications	Field corn; Seed corn; Sweetcorn; Popcorn; Silage corn; Sugarcane; Cereals including wheat and barley
Efficacy & activity	-

GB regulatory status

GB COPR regulatory status	Not approved
Date COPR inclusion expires	Not applicable
GB LERAP status	No UK approval for use as a plant protection agent

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status	Not approved
Dossier rapporteur/co-rapporteur	Not applicable
Date EC 1107/2009 inclusion expires	Not applicable
EU Candidate for substitution (CfS)	Not applicable
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
Approved for use (✓) under EC 1107/2009 by Mutual Recognition of Authorisation and/or national regulations in the following EEA countries	ISIceland NONorway

Additional information

Also used in	-

Chemical structure

Isomerism	Bicyclopyrone exhibits isomerism that arises from a chiral centre within the molecule, where four different substituents are bonded to a single carbon atom, resulting in non-superimposable mirror images (R and S configurations). Additionally, during metabolic processes in plants and animals, bicyclopyrone can form desmethyl monohydroxy isomers, which are structural isomers differing by the loss of a methyl group and the addition of a hydroxyl group at different positions on the molecule. Bicyclopyrone is usually is marketed and used as a racemic mixture.
Chemical formula	C₁₉H₂₀F₃NO₅
Canonical SMILES	COCCOCC1=C(C=CC(=N1)C(F)(F)F)C(=C2C(=O)C3CCC(C3)C2=O)O
Isomeric SMILES	COCCOCC1=C(C=CC(=N1)C(F)(F)F)C(=C2C(=O)[C@@H]3CC[C@@H](C3)C2=O)O
International Chemical Identifier key (InChIKey)	AIAYSXFWIUNXRC-PHIMTYICSA-N
International Chemical Identifier (InChI)	InChI=1S/C19H20F3NO5/c1-27-6-7-28-9-13-12(4-5-14(23-13)19(20,21)22)18(26)15-16(24)10-2-3-11(8-10)17(15)25/h4-5,10-11,24H,2-3,6-9H2,1H3
2D structure diagram/image available?	Yes

General status

Pesticide type		Herbicide
Substance groups		Triketone herbicide
Minimum active substance purity		-
Known relevant impurities		-
Substance origin		Synthetic
Mode of action		Hydroxyphenylpyruvate dioxygenase (HPPD) inhibitor - causes plant bleaching
CAS RN		352010-68-5
Alternative/old CAS RN		365400-11-9
EC number		688-487-1
CIPAC number		None allocated
US EPA chemical code		018986
PubChem CID		11188745
CLP index number		No data found
Molecular mass		399.36
PIN (Preferred Identification Name)		rac-(1R,5R)-4-hydroxy-3-{2-[(2-methoxyethoxy)methyl]-6-(trifluoromethyl)pyridine-3-carbonyl}bicyclo[3.2.1]oct-3-en-2-one
IUPAC name		4-hydroxy-3-{2-[(2-methoxyethoxy)methyl]-6-(trifluoromethyl)-3-pyridylcarbonyl}bicyclo[3.2.1]oct-3-en-2-one
CAS name		4-hydroxy-3-[[2-[(2-methoxyethoxy)methyl]-6-(trifluoromethyl)-3-pyridinyl]carbonyl]bicyclo[3.2.1]oct-3-en-2-one
Listed (✓) under		UK Poisons List Order 1972 Rotterdam Convention Montreal Protocol XNo The Poisons List Order 1972 XNo Rotterdam Convention XNo Montreal Protocol Stockholm Convention OSPAR EU Water Framework Directive XNo Stockholm Convention XNo OSPAR XNo EU Water Framework Directive
Relevant Environmental Water Quality Standards		-
Forever chemical		PFAS
Highly Hazardous Pesticide (HHP)	Type I	Yes [ C4 Criterion 4: Pesticide active ingredients that meet the criteria of reproductive toxicity Categories 1A and 1B of the Globally Harmonized System on Classification and Labelling of Chemicals (GHS) (those with a CLP classification of H360) ]
	Type II	Yes [ R04 Rule 4: Pesticide active ingredients that meet the criteria of reproductive toxicity Categories 1A and 1B of the Globally Harmonized System on Classification and Labelling of Chemicals (GHS) (those with a CLP classification of H360) ]
Other status information		Possible groundwater contaminant
Herbicide Resistance Class (HRAC MoA class)		F2
Herbicide Resistance Class (WSSA MoA class)		27
Insecticide Resistance Class (IRAC MoA class)		Not applicable
Fungicide Resistance Class (FRAC MOA class)		Not applicable
Examples of recorded resistance		None identified
Physical state		White powdery solid

Commercial

Property	Value
Availability status	Current
Introduction & key dates	2014, first registered USA
Example manufacturers & suppliers of products using this active now or historically	Syngenta
Example products using this active	Acuron Talinor
Formulation and application details	-
Commercial production	-
Impact on climate of production and use	-

ENVIRONMENTAL FATE

Property		Value	Source; quality score; and other information	Interpretation
Solubility - In water at 20 °C at pH 7 (mg l⁻¹)		1200	P5 P = Other non-EU, UK or US Governments and Regulators 5 = Verified data used for regulatory purposes	High
Solubility - In organic solvents at 20 °C (mg l⁻¹)		500000	P5 P = Other non-EU, UK or US Governments and Regulators 5 = Verified data used for regulatory purposes Acetone	-
		500000	P5 P = Other non-EU, UK or US Governments and Regulators 5 = Verified data used for regulatory purposes Ethyl acetate	-
		91000	P5 P = Other non-EU, UK or US Governments and Regulators 5 = Verified data used for regulatory purposes Toluene	-
		8999	P5 P = Other non-EU, UK or US Governments and Regulators 5 = Verified data used for regulatory purposes Hexane	-
Melting point (°C)		65.3	P5 P = Other non-EU, UK or US Governments and Regulators 5 = Verified data used for regulatory purposes	-
Boiling point (°C)		489.5	V3 V = ChemID Online Databases; Chemspider; PubChem. (ChemID ) 3 = Unverified data of known source	-
Degradation point (°C)		-	-	-
Flashpoint (°C)		249.9	V3 V = ChemID Online Databases; Chemspider; PubChem. (ChemID ) 3 = Unverified data of known source	-
Octanol-water partition coefficient at pH 7, 20 °C	P	6.31 X 10-02	Calculated	-
	Log P	-1.2	P5 P = Other non-EU, UK or US Governments and Regulators 5 = Verified data used for regulatory purposes	Low
Fat solubility of residues	Solubility	-	-	-
	Data type	-	-	-
Density (g ml⁻¹)		1.503	P5 P = Other non-EU, UK or US Governments and Regulators 5 = Verified data used for regulatory purposes	-
Dissociation constant pKa) at 25 °C		3.06	P5 P = Other non-EU, UK or US Governments and Regulators 5 = Verified data used for regulatory purposes	-
		-
Vapour pressure at 20 °C (mPa)		5.0 X 10-03	P5 P = Other non-EU, UK or US Governments and Regulators 5 = Verified data used for regulatory purposes	Low volatility
Henry's law constant at 25 °C (Pa m³ mol⁻¹)		1.7 X 10-08	P5 P = Other non-EU, UK or US Governments and Regulators 5 = Verified data used for regulatory purposes	Non-volatile
Volatilisation as max % of applied dose lost	From plant surface	-	-	-
	From soil surface	-	-	-
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)	213.2	F4 F = U.S. EPA ECOTOX database / U.S. EPA pesticide fate database / Miscellaneous WHO documents / FAO data, IPCS INCHEM data (US EPA Databases Related to Pesticide Risk Assessment ) 4 = Verified data	Persistent
	DT₅₀ (lab at 20 °C)	-	-	-
	DT₅₀ (field)	-	-	-
	DT₉₀ (lab at 20 °C)	-	-	-
	DT₉₀ (field)	-	-	-
	DT₅₀ modelling endpoint	-	-	-
	Note	-
Dissipation rate RL₅₀ (days) on plant matrix	Value	-	-	-
	Note	-
Dissipation rate RL₅₀ (days) on and in plant matrix	Value	-	-	-
	Note	-
Aqueous photolysis DT₅₀ (days) at pH 7	Value	43	F4 F = U.S. EPA ECOTOX database / U.S. EPA pesticide fate database / Miscellaneous WHO documents / FAO data, IPCS INCHEM data (US EPA Databases Related to Pesticide Risk Assessment ) 4 = Verified data	Stable
	Note	DT₅₀ given as between 11 and 75 days
Aqueous hydrolysis DT₅₀ (days) at 20 °C and pH 7	Value	Stable	F4 F = U.S. EPA ECOTOX database / U.S. EPA pesticide fate database / Miscellaneous WHO documents / FAO data, IPCS INCHEM data (US EPA Databases Related to Pesticide Risk Assessment ) 4 = Verified data	Stable
	Note	Stable at all relevant pH values
Water-sediment DT₅₀ (days)		-	-	-
Water phase only DT₅₀ (days)		-	-	-
Sediment phase only DT₅₀ (days)		-	-	-
Air degradation		As this parameter is not normally measured directly, a surrogate measure is used: ‘Photochemical oxidative DT₅₀’. Where data is available, this can be found in the Fate Indices section below.
Decay in stored produce DT₅₀		-

Soil adsorption and mobility

Property		Value	Source; quality score; and other information	Interpretation
Linear	Kd (mL g⁻¹)	-	-	-
	Koc (mL g⁻¹)	-
	Notes and range	-
Freundlich	Kf (mL g⁻¹)	0.59	F4 F = U.S. EPA ECOTOX database / U.S. EPA pesticide fate database / Miscellaneous WHO documents / FAO data, IPCS INCHEM data (US EPA Databases Related to Pesticide Risk Assessment ) 4 = Verified data	-
	Kfoc (mL g⁻¹)	-
	1/n	-
	Notes and range	-
pH sensitivity		-

Fate indices

Property		Value	Source; quality score; and other information	Interpretation
GUS leaching potential index		-	-	-
SCI-GROW groundwater index (μg l⁻¹) for a 1 kg ha⁻¹ or 1 l ha⁻¹ application rate	Value	Cannot be calculated	-	-
	Note	-
Potential for particle bound transport index		-	-	-
Potential for loss via drain flow		-	-	-
Photochemical oxidative DT₅₀ (hrs) as indicator of long-range air transport risk		-	-	-
Bio-concentration factor	BCF (l kg⁻¹)	-	-	-
	CT₅₀ (days)	-		-

Known soil metabolites

Metabolite	Major/Minor fraction	Estimated maximum occurrence fraction	Notes
6-(trifluoromethyl)pyridine-2,3-dicarboxylic acid (Ref: SYN 504810)	Major fraction	-	-
(1S,3R)-cyclopentane-1,3-dicarboxylic acid (Ref: NOA 412101)	Major fraction	-	-
[3-(2-hydroxy-4-oxo-bicyclo[3.2.1]oct-2-ene-3-carbonyl)-6-trifluoromethyl- pyridine-2-yl-methyloxy]-acetic acid (Ref: SYN 545859)	Major fraction	-	-
6-(trifluoromethyl)pyridin-3-ol-2-carboxylic acid (Ref: SYN 545680)	Major fraction	-	-
2-(2-methoxy-ethoxymethyl)-6-trifluoromethyl-nicotinic acid (Ref: SYN 503780)	Major fraction	-	-
2-(hydroxymethyl)-6-trifuoromethyl-nicotinic acid (Ref: CSAA 806573)	Major fraction	-	-
4-hydroxy-3-(2-(2-methoxy-ethoxymethyl)-6-(trifluoromethyl)-pyridine-3-carbonyl]-bicyclo [3.2.1]oct-3-en-2-one (Ref: NOA 449280)	Major fraction	-	-

Known groundwater metabolites

None

Other known metabolites

Metabolite name and reference	Aliases	Formation medium / Rate	Estimated maximum occurrence fraction
6-(trifluoromethyl)pyridine-2,3-dicarboxylic acid (Ref: SYN 504810)	CSCC 163768	Water	-
Ref: SYN 545859	CSCD 642512	Water	-
6-(trifluoromethyl)pyridin-3-ol-2-carboxylic acid (Ref: SYN 545680)	CSCD 656832	Water	-
2-(2-methoxy-ethoxymethyl)-6-trifluoromethyl-nicotinic acid	SYN 503780	Water	-
-	CSAA 806573	Water	-
Ref: SYN 503780	CSAA 794148	Water	-
4-hydroxy-3-(2-(2-methoxy-ethoxymethyl)-6-(trifluoromethyl)-pyridine-3-carbonyl]-bicyclo [3.2.1]oct-3-en-2-one	NOA 449280	Water	-

ECOTOXICOLOGY

Terrestrial ecotoxicology

Property		Value	Source; quality score; and other information	Interpretation
Mammals - Acute oral LD₅₀ (mg kg⁻¹)		> 5000	P5 P = Other non-EU, UK or US Governments and Regulators 5 = Verified data used for regulatory purposes Rat	Low
Mammals - Short term dietary NOEL	(mg kg⁻¹)	-	-	-
	(ppm diet)	-		-
Mammals - Chronic 21d NOAEL (mg kg⁻¹ bw d⁻¹)		0.72	P5 P = Other non-EU, UK or US Governments and Regulators 5 = Verified data used for regulatory purposes Rat	High
Birds - Acute LD₅₀ (mg kg⁻¹)		-	-	-
Birds - Short term dietary (LC₅₀/LD₅₀)		-	-	-
Birds - Chronic 21d NOEL (mg kg⁻¹ bw d⁻¹)		-	-	-
Earthworms - Acute 14 day LC₅₀ (mg kg⁻¹ dw soil)		-	-	-
Earthworms - Chronic NOEC, reproduction (mg kg⁻¹ dw soil)		-	-	-
Soil micro-organisms		-	-	-
Collembola	Acute LC₅₀ (mg kg⁻¹)	-	-	-
	Chronic NOEC (mg kg⁻¹)	-	-	-
Non-target plants	Vegetative vigour ER₅₀ (g ha⁻¹)	-	-	-
	Seedling emergence ER₅₀ (g ha⁻¹)	-	-	-
Honeybees (Apis spp.)	Contact acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)	780.0	E4 E = Manufacturers safety data sheets 4 = Verified data	Low
	Oral acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)	784.4	E4 E = Manufacturers safety data sheets 4 = Verified data	Low
	Unknown mode acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)	-	-	-
	Chronic	-	-	-
	Notes	-
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 bee species (1)	Acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg insect⁻¹)	-	-	-
	Mode of exposure	-
Other bee species (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
Temperate Freshwater Fish - Acute 96 hour LC₅₀ (mg l⁻¹)		46.9	E3 E = Manufacturers safety data sheets 3 = Unverified data of known source Unknown species	Moderate
Temperate Freshwater Fish - Chronic 21 day NOEC (mg l⁻¹)		-	-	-
Tropical Freshwater Fish - Acute 96 hour LC₅₀ (mg l⁻¹)		-	-	-
Temperate Freshwater Aquatic invertebrates - Acute 48 hour EC₅₀ (mg l⁻¹)		46.7	E4 E = Manufacturers safety data sheets 4 = Verified data Daphnia magna	Moderate
Temperate Freshwater Aquatic invertebrates - Chronic 21 day NOEC (mg l⁻¹)		-	-	-
Tropical Freshwater Aquatic invertebrates - Acute 48 hour EC₅₀ (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 (free-floating, fonds growth, fresh) - 7 day (mg l⁻¹) (EC₅₀)		0.013	E4 E = Manufacturers safety data sheets 4 = Verified data Lemna gibba	Moderate
Aquatic plants (rooted, growth rate, fresh) - 14 day (mg l⁻¹)		-	-	-
Algae - Acute (growth rate, fresh; mg l⁻¹)		-	-	-
Algae - Chronic (growth rate, fresh; mg l⁻¹)		-	-	-
Mesocosm study data	NOEAEC mg l⁻¹	-	-	-
	NOEAEC mg l⁻¹	-	-	-
Marine bivalves		-	-	-

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)		> 5000	P5 P = Other non-EU, UK or US Governments and Regulators 5 = Verified data used for regulatory purposes Rat	Low
Mammals - Dermal LD₅₀ (mg kg⁻¹ body weight)		5000	P5 P = Other non-EU, UK or US Governments and Regulators 5 = Verified data used for regulatory purposes Rat	-
Mammals - Inhalation LC₅₀ (mg l⁻¹)		> 5.2	P5 P = Other non-EU, UK or US Governments and Regulators 5 = Verified data used for regulatory purposes Rat	-
Other Mammal toxicity endpoints		-	-	-
ADI - Acceptable Daily Intake (mg kg⁻¹ bw day⁻¹)		-	-	-
ARfD - Acute Reference Dose (mg kg⁻¹ bw day⁻¹)		0.01	P4 P = Other non-EU, UK or US Governments and Regulators 4 = Verified data Rabbit US data	-
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		-	-	-
Exposure Routes	Public	-
	Occupational	-
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 (hazard-based)		Carcinogen Genotoxic Endocrine disruptor ?Possibly, status not identified 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 ; E3 E = Unspecified genotoxicity type (miscellaneous data source) 3 = Negative No data found Reproduction / development effects Acetyl cholinesterase inhibitor Neurotoxicant ✓Yes, known to cause a problem XNo, known not to cause a problem XNo, known not to cause a problem Respiratory tract irritant Skin irritant Skin sensitiser No data found XNo, known not to cause a problem XNo, known not to cause a problem Eye irritant Phototoxicant   ?Possibly, status not identified No data found
General human health issues		Published studies concluded that bicyclopyrone is carcinogenic in rats, but not in mice

Handling issues

Property	Value and interpretation
General	No information available
CLP classification 2013	Health: H360D Environment: H400, H410
WHO Classification	U (Unlikely to present an acute hazard)
UN Number	-
Waste disposal & packaging	-
Shelf-life, storage, stability and reactivity	-

TRANSLATIONS

Language	Name
English	bicyclopyrone
French	-
German	-
Danish	-
Italian	-
Spanish	-
Greek	-
Polish	-
Swedish	-
Hungarian	-
Dutch	-
Norwegian	-

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Record last updated:	10/10/2025
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