Isocycloseram (Ref: SYN547407)	Last updated: 24/10/2025
(Also known as: Isocycloceram)

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SUMMARY

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	Highly Hazardous Pesticide
Environmental fate High alert: Very persistent Warning: Significant data are missing	Ecotoxicity High alert: Daphnia acute ecotoxicity: High; Bees acute contact ecotoxicity: High; Bees acute oral ecotoxicity: High; Bees acute unknown ecotoxicity: High	Human health Low alert Warning: Significant data are missing	Highly Hazardous Pesticide (HHP) Type II alert

GENERAL INFORMATION

Description	A broad‐spectrum arylisoxazoline insecticide that is active against a wide range of insect pests.
Example pests controlled	Stinkbugs; Thrips; Aphids; Caterpillars; Beetles; Flies; Mites; Diamondback moth; Cabbage white butterfly
Example applications	Corn; Coffee; Cotton; Rice; Fruit including apples and pears; Brassicas; Ornamentals
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	No
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	Canada; Argentina; Australia

Chemical structure

Isomerism	Isocycloseram exhibits stereoisomerism primarily through optical isomerism due to the presence of two chiral centres in its structure. The first is located at the C4 position of the isoxazoline ring, where the carbon is attached to four distinct substituents. The second chiral centre is at the C4 position of the 1,2-oxazolidin-3-one ring, also bonded to three substituents and the carbonyl-bearing carbon. These asymmetric carbons enable the formation of up to four stereoisomers: two pairs of enantiomers or a combination of enantiomers and diastereomers, depending on the relative configurations. However, commercial formulations of isocycloseram are typically a specific diastereomeric mixture.
Chemical formula	C₂₃H₁₉Cl₂F₄N₃O₄
Canonical SMILES	CCN1C(=O)C(CO1)NC(=O)C2=C(C=C(C=C2)C3=NOC(C3)(C4=CC(=C(C(=C4)Cl)F)Cl)C(F)(F)F)C
Isomeric SMILES	CCN1C(=O)[C@@H](CO1)NC(=O)C2=C(C=C(C=C2)C3=NO[C@](C3)(C4=CC(=C(C(=C4)Cl)F)Cl)C(F)(F)F)C
International Chemical Identifier key (InChIKey)	WLSQDEYDCAGPIR-UHFFFAOYSA-N
International Chemical Identifier (InChI)	InChI=1S/C23H19Cl2F4N3O4/c1-3-32-21(34)18(10-35-32)30-20(33)14-5-4-12(6-11(14)2)17-9-22(36-31-17,23(27,28)29)13-7-15(24)19(26)16(25)8-13/h4-8,18H,3,9-10H2,1-2H3,(H,30,33)
2D structure diagram/image available?	Yes

Cambridge Crystallographic Data Centre diagrams

Common Name	Relationship	Link
Isocycloseram	-
Isocycloseram	-

General status

Pesticide type		Insecticide; Miticide
Substance groups		Isoxazoline insecticide
Minimum active substance purity		-
Known relevant impurities		-
Substance origin		Synthetic
Mode of action		A non‐competitive GABA‐gated chloride channel antagonist which causes rapid pest feeding cessation.
CAS RN		2061933-85-3
EC number		No data found
CIPAC number		None allocated
US EPA chemical code		-
PubChem CID		130358867
CLP index number		No data found
Molecular mass		548.3
PIN (Preferred Identification Name)		4-[(5E)-5-(3,5-dichloro-4-fluorophenyl)-5-(trifluoromethyl)-4,5-dihydro-1,2-oxazol-3-yl]-N-[(4E)-2-ethyl-3-oxo-1,2-oxazolidin-4-yl]-2-methylbenzamide, containing 80–100% of the (5S,4R)-isomer
IUPAC name		4-[(5RS)-5-(3,5-dichloro-4-fluorophenyl)-4,5-dihydro-5-(trifluoromethyl)isoxazol-3-yl]-N-[(4RS)-2-ethyl-3-oxoisoxazolidin-4-yl]-o-toluamide, containing 80–100% of the (5S,4R)-isomer
CAS name		4-[5-(3,5-dichloro-4-fluorophenyl)-4,5-dihydro-5-(trifluoromethyl)-3-isoxazolyl]-N-(2-ethyl-3-oxo-4-isoxazolidinyl)-2-methylbenzamide
Global Governance status: 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	-
	Type II	Yes [ R09 Rule 9: Pesticide active ingredients that have demonstrated a high aquatic toxicity (where acute ecotoxicity for fish, invertebrates or algae =< 0.1 mg l⁻¹) ; R10 Rule 10: Pesticide active ingredients that have demonstrated a high toxicity to bees (where contact or oral bee toxicity =< 2 μg bee⁻¹) ; R11 Rule 11: Pesticide active ingredients that are environmentally persistent (where sediment phase only DT₅₀ => 90 days or water phase only DT₅₀ => 90 days or DT₅₀ (field) => 60 days (note lab values are used when field values are not available)) ; R12 Rule 12: Pesticide active ingredients that are bioaccumulative (where bio-concentration factor (BCF) > 2000 l kg⁻¹ (if BCF is not available, where Log P >=5)) ]
Other status information		-
Herbicide Resistance Class (HRAC MoA class)		Not applicable
Herbicide Resistance Class (WSSA MoA class)		Not applicable
Insecticide Resistance Class (IRAC MoA class)		30
Fungicide Resistance Class (FRAC MOA class)		Not applicable
Examples of recorded resistance		None identified
Physical state		Off-white coloured powder with characteristic sweet odour

Commercial

Property	Value
Availability status	Novel
Introduction & key dates	2018, first announced; 2021, first approvals; 2025, commercial launch USA
Example manufacturers & suppliers of products using this active now or historically	Syngenta
Example products using this active	Plinazolin Technology Equento Incipio Opello Vertento Zivalgo
Formulation and application details	Offered in a variety of formulations including seed treatments, foliar sprays and soil-applied products
Commercial production	The commercial production of isocycloseram involves multi-step organic synthesis, starting from aromatic precursors that undergo cyclisation reactions to form the unique spirocyclic isoxazoline core.
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)		1.2	P5 P = Other non-EU, UK or US Governments and Regulators 5 = Verified data used for regulatory purposes	Low
Solubility - In organic solvents at 20 °C (mg l⁻¹)		400000	P5 P = Other non-EU, UK or US Governments and Regulators 5 = Verified data used for regulatory purposes Dichloromethane	-
		270000	P5 P = Other non-EU, UK or US Governments and Regulators 5 = Verified data used for regulatory purposes Acetone	-
		190000	P5 P = Other non-EU, UK or US Governments and Regulators 5 = Verified data used for regulatory purposes Ethyl acetate	-
		39000	P5 P = Other non-EU, UK or US Governments and Regulators 5 = Verified data used for regulatory purposes Hexane	-
Melting point (°C)		138.9	P5 P = Other non-EU, UK or US Governments and Regulators 5 = Verified data used for regulatory purposes	-
Boiling point (°C)		Decomposes before boiling	P5 P = Other non-EU, UK or US Governments and Regulators 5 = Verified data used for regulatory purposes	-
Degradation point (°C)		178	P4 P = Other non-EU, UK or US Governments and Regulators 4 = Verified data	-
Flashpoint (°C)		-	-	-
Octanol-water partition coefficient at pH 7, 20 °C	P	1.00 X 1005	Calculated	-
	Log P	5.0	P5 P = Other non-EU, UK or US Governments and Regulators 5 = Verified data used for regulatory purposes	High
Fat solubility of residues	Solubility	-	-	-
	Data type	-	-	-
Density (g ml⁻¹)		1.5	P4 P = Other non-EU, UK or US Governments and Regulators 4 = Verified data	-
Dissociation constant pKa) at 25 °C		Does not dissociate	P5 P = Other non-EU, UK or US Governments and Regulators 5 = Verified data used for regulatory purposes	-
		-
Vapour pressure at 20 °C (mPa)		6.2 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)		2.83 X 10-03	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		Neutral soln: 265nm=25004, 290nm=6392 Acidic soln: 265nm=22632, 290nm=4906 Basic soln: 265nm=22363, 290 nm=5084	P5 P = Other non-EU, UK or US Governments and Regulators 5 = Verified data used for regulatory purposes	-
Surface tension (mN m⁻¹)		-	-	-

Degradation

Property		Value	Source; quality score; and other information	Interpretation
General biodegradability		Not readily biodegradable
Soil degradation (days) (aerobic)	DT₅₀ (typical)	390	P4 P = Other non-EU, UK or US Governments and Regulators 4 = Verified data	Very persistent
	DT₅₀ (lab at 20 °C)	390	P4 P = Other non-EU, UK or US Governments and Regulators 4 = Verified data	Very persistent
	DT₅₀ (field)	-	-	-
	DT₉₀ (lab at 20 °C)	-	-	-
	DT₉₀ (field)	-	-	-
	DT₅₀ modelling endpoint	-	-	-
	Note	Australian 2022 public dosier: Lab studies DT₅₀ range 56-723 days
Dissipation rate RL₅₀ (days) on plant matrix	Value	-	-	-
	Note	-
Dissipation rate RL₅₀ (days) on and in plant matrix	Value	2.7	R3 R = Peer reviewed scientific publications 3 = Unverified data of known source	-
	Note	Published literature Rl50 range 2.2-3.3 days, 2 field crops, n=2
Aqueous photolysis DT₅₀ (days) at pH 7	Value	-	-	-
	Note	-
Aqueous hydrolysis DT₅₀ (days) at 20 °C and pH 7	Value	Stable	P5 P = Other non-EU, UK or US Governments and Regulators 5 = Verified data used for regulatory purposes	Stable
	Note	Stable at pH 4-7, hydrolyses quickly at pH 9
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)	-	-	-
	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		6.2	P5 P = Other non-EU, UK or US Governments and Regulators 5 = Verified data used for regulatory purposes Calculated using the Atkinson method. Assumed 1.5E+06 OH/cm³, 12 hr. EU trigger for long-range transport is DT₅₀ in air <2 days.	Below the level of concern for long-range air transport
Bio-concentration factor	BCF (l kg⁻¹)	-	-	-
	CT₅₀ (days)	-		-

Known soil metabolites

Metabolite	Major/Minor fraction	Estimated maximum occurrence fraction	Notes
Ref: SYN549543	-	-	-
Ref: SYN549544	-	-	-
Ref: SYN549543	-	-	-
Ref: SYN549107	Major fraction	0.260	-
Ref: SYN550738	Major fraction	0.110	-

Known groundwater metabolites

None

Other known metabolites

Metabolite name and reference	Aliases	Formation medium / Rate	Estimated maximum occurrence fraction
Ref: SYN549431	-	Plant	-
Ref: SYN548569	-	Animal	-
Ref: SYN549431	-	Animal	-
Ref: SYN549436	-	Animal	-
Ref: SYN549544	-	Animal	-

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)		-	-	-
Birds - Acute LD₅₀ (mg kg⁻¹)		> 2000	P4 P = Other non-EU, UK or US Governments and Regulators 4 = Verified data Unknown species	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 dw soil)		> 500	P5 P = Other non-EU, UK or US Governments and Regulators 5 = Verified data used for regulatory purposes Eisenia foetida corr	Moderate
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)	0.26	P5 P = Other non-EU, UK or US Governments and Regulators 5 = Verified data used for regulatory purposes Apis mellifera	High
	Oral acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)	0.28	P5 P = Other non-EU, UK or US Governments and Regulators 5 = Verified data used for regulatory purposes Apis mellifera	High
	Unknown mode acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)	0.08	P5 P = Other non-EU, UK or US Governments and Regulators 5 = Verified data used for regulatory purposes Apis mellifera bee larvae	High
	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) -		0.0059	P5 P = Other non-EU, UK or US Governments and Regulators 5 = Verified data used for regulatory purposes Typhlodromus pyri	-
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)		0.13	P5 P = Other non-EU, UK or US Governments and Regulators 5 = Verified data used for regulatory purposes Oncorhynchus mykiss	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)		0.017	P5 P = Other non-EU, UK or US Governments and Regulators 5 = Verified data used for regulatory purposes Daphnia magna	High
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)		0.000015	P5 P = Other non-EU, UK or US Governments and Regulators 5 = Verified data used for regulatory purposes Chironomus riparius	High
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)		1.2	P5 P = Other non-EU, UK or US Governments and Regulators 5 = Verified data used for regulatory purposes Lemna gibba	Moderate
Aquatic plants (rooted, growth rate, fresh) - 14 day (mg l⁻¹)		-	-	-
Algae - Acute (growth rate, fresh; mg l⁻¹) (EC₅₀)		0.27	P5 P = Other non-EU, UK or US Governments and Regulators 5 = Verified data used for regulatory purposes Skeletonema costatum	Moderate
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)		-	-	-
Mammals - Inhalation LC₅₀ (mg l⁻¹)		-	-	-
Other Mammal toxicity endpoints		-	-	-
ADI - Acceptable Daily Intake (mg kg⁻¹ bw day⁻¹)		0.02	P5 P = Other non-EU, UK or US Governments and Regulators 5 = Verified data used for regulatory purposes Australia	-
ARfD - Acute Reference Dose (mg kg⁻¹ bw day⁻¹)		0.08	P5 P = Other non-EU, UK or US Governments and Regulators 5 = Verified data used for regulatory purposes Australia	-
AAOEL - Acute Acceptable Operator Exposure Level (mg kg⁻¹ bw day⁻¹)		[Appropriate PPE/PPC is recomended]	P5 P = Other non-EU, UK or US Governments and Regulators 5 = Verified data used for regulatory purposes	-
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		Mainly excreted via bile and faeces, and to lesser extent, via urine	P5 P = Other non-EU, UK or US Governments and Regulators 5 = Verified data used for regulatory purposes	-

Health issues

Specific human health issues (hazard-based)		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 ; E3 E = Unspecified genotoxicity type (miscellaneous data source) 3 = Negative No data found Reproduction / development effects Acetyl cholinesterase inhibitor Neurotoxicant XNo, known not to cause a problem 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   ?Possibly, status not identified No data found
General human health issues		No information available

Handling issues

Property	Value and interpretation
General	Not explosive or oxidising Not highly flammable
CLP classification 2013	Environment: H400, H410
WHO Classification	Not listed (Not listed)
UN Number	P5
Waste disposal & packaging	-
Shelf-life, storage, stability and reactivity	Stable for around 12 months at 20 DegC. Less stable at higher temperatures

TRANSLATIONS

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

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Record last updated:	24/10/2025
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