Trinexapac-ethyl (Ref: CGA 163935)

Trinexapac-ethyl (Ref: CGA 163935)	Last updated: 25/05/2025
(Also known as: trinexapac; cimectacarb-ethyl; cimectacarb)

SUMMARY

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 Moderate alert: GUS: Transition state; Drainflow: Moderately mobile	Ecotoxicity Moderate alert: Birds chronic ecotoxicity: Moderate; Fish acute ecotoxicity: Moderate; Fish chronic ecotoxicity: Moderate; Daphnia chronic ecotoxicity: Moderate; Earthworms acute ecotoxicity: Moderate	Human health Low alert

GENERAL INFORMATION

Description

A plant growth regulator used to prevent lodging. Also used on turf and amenity grassland to slow growth.

Example pests controlled

Growth - reduces lodging and growth

Example applications

Cereals including wheat, barley, oats, rye; Oilseed rape; Amenity turf and grass

Efficacy & activity

Availability status

Current

Introduction & key dates

1992, registered Switzerland

GB regulatory status

GB COPR regulatory status

Approved

Date COPR inclusion expires

30/04/2029

GB LERAP status

None

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status

Approved

Dossier rapporteur/co-rapporteur

Lithuania/Latvia

Date EC 1107/2009 inclusion expires

30/04/2039

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
✓	✓	✓	✓	✓	✓	✓	✓	✓

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

Australia; Morocco

Chemical structure

Isomerism

None

Chemical formula

C₁₃H₁₆O₅

Canonical SMILES

CCOC(=O)C1CC(=O)C(=C(C2CC2)O)C(=O)C1

Isomeric SMILES

International Chemical Identifier key (InChIKey)

RVKCCVTVZORVGD-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C13H16O5/c1-2-18-13(17)8-5-9(14)11(10(15)6-8)12(16)7-3-4-7/h7-8,16H,2-6H2,1H3/b12-11-

2D structure diagram/image available?

Yes

General status

Pesticide type

Plant Growth Regulator

Substance groups

Cyclohexanecarboxylate compound; Unclassified PGR

Minimum active substance purity

940 g kg⁻¹

Known relevant impurities

EU dossier - None declared

Substance origin

Synthetic

Mode of action

Gibberellin biosynthesis inhibitor thus slowing growth

CAS RN

95266-40-3

EC number

680-302-2

CIPAC number

732.202

US EPA chemical code

112602

PubChem CID

92421

CLP index number

No data found

Molecular mass

252.26

PIN (Preferred Identification Name)

ethyl (RS)-4-cyclopropyl(hydroxy)methylene-3,5-dioxocyclohexanecarboxylate

IUPAC name

ethyl (RS)-4-cyclopropyl(hydroxy)methylene-3,5-dioxocyclohexanecarboxylate

CAS name

ethyl 4-(cyclopropylhydroxymethylene)-3,5-dioxocyclohexanecarboxylate

Other status information

Relevant Environmental Water Quality Standards

Herbicide Resistance Class (HRAC MoA class)

Not applicable

Herbicide Resistance Class (WSSA MoA class)

Not applicable

Insecticide Resistance Class (IRAC MoA class)

Not applicable

Fungicide Resistance Class (FRAC MOA class)

Not applicable

Examples of recorded resistance

Physical state

White solid at 996 g/kg or purer. Less pure substance tends to be a reddish brown solid.

Formulations

Property

Value

Example manufacturers & suppliers of products using this active now or historically

AgriGuard
Clayton
Novartis
Pan Agriculture
Scotts

Example products using this active

Moddus
Stunt
Groslow
Clipless
Cutaway
Duet Max
RegiMax PGR

Formulation and application details

Often supplied as emulsifiable or a soluble concentrates that are mixed with water and used as a spray

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

Solubility - In water at 20 °C (mg l⁻¹)

10200

High

Solubility - In organic solvents at 20 °C (mg l⁻¹)

500000

Acetone

500000

Methanol

45000

Hexane

420000

n-Octanol

Melting point (°C)

36.3

Boiling point (°C)

270

Degradation point (°C)

310

Flashpoint (°C)

156

Octanol-water partition coefficient at pH 7, 20 °C

5.13 X 10^-01

Calculated

Log P

-0.29

at 25 °C

Low

Fat solubility of residues

Solubility

Insoluble

Data type

Regulatory data

Density (g ml⁻¹)

1.31

Dissociation constant pKa) at 25 °C

4.57

Weak acid

Vapour pressure at 20 °C (mPa)

2.16

Low volatility. If applied directly to plants or soil, drift is a concern & mitigation is advisable

Henry's law constant at 25 °C (Pa m³ mol⁻¹)

5.40 X 10^-04

Non-volatile

Volatilisation as max % of applied dose lost

From plant surface

24 hr

Volatilisation is not considered critical for air pollution

From soil surface

Negligible

24 hr

Maximum UV-vis absorption L mol⁻¹ cm⁻¹

Neutral solution: 240.2nm = 9335, 277.4nm = 13976
Acidic solution: 240.0nm = 11712, 280.4nm = 12368
Basic solution: 270.8nm = 21320

Surface tension (mN m⁻¹)

58.3

at 22.5 °C 99.6%

Degradation

Property

Value

Source; quality score; and other information

Interpretation

General biodegradability

Soil degradation (days) (aerobic)

DT₅₀ (typical)

0.16

Non-persistent

DT₅₀ (lab at 20 °C)

0.16

Non-persistent

DT₅₀ (field)

14.6

Non-persistent

DT₉₀ (lab at 20 °C)

0.90

Non-persistent

DT₉₀ (field)

DT₅₀ modelling endpoint

0.1

Note

2017 EU dossier lab studies DT₅₀ range 0.045-0.72 days, DT₉₀ range 0.15-2.4 days, soils=5; Field studies from 2005 EU dossier DT₅₀ range 6.9-21 days; Other sources: DT₅₀ 3 days (DW4)

Dissipation rate RL₅₀ (days) on plant matrix

Value

Note

Dissipation rate RL₅₀ (days) on and in plant matrix

Value

1.65, Wheat, whole plant, n=1

Note

Aqueous photolysis DT₅₀ (days) at pH 7

Value

Slow

Note

Data for artificial sunlight, 40 deg N, faster at higher temperatures

Aqueous hydrolysis DT₅₀ (days) at 20 °C and pH 7

Value

868

Very persistent

Note

pH sensitive: Stable at pH 5 and pH 7, DT₅₀ 10.9 days at pH 9

Water-sediment DT₅₀ (days)

4.5

Fast

Water phase only DT₅₀ (days)

4.2

Moderately fast

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

K_d (mL g⁻¹)

K_oc (mL g⁻¹)

Notes and range

Freundlich

K_f (mL g⁻¹)

5.15

Moderately mobile

K_foc (mL g⁻¹)

280

¹/_n

0.94

Notes and range

EU dossier K_f range 0.66-17.8 mL g⁻¹, K_foc range 60-629 mL g⁻¹, ¹/_n range 0.92-1.01, Soils=4

pH sensitivity

Yes - decreased sorption at increasing pH

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

1.81

Calculated

Transition state

SCI-GROW groundwater index (μg l⁻¹) for a 1 kg ha⁻¹ or 1 l ha⁻¹ application rate

Value

4.32 X 10^-02

Calculated

Note

Potential for particle bound transport index

Low

Calculated

Potential for loss via drain flow

Moderately mobile

Calculated

Photochemical oxidative DT₅₀ (hrs) as indicator of long-range air transport risk

4.08

Calculated using the Atkinson method

Below the level of concern for long-range air transport

Bio-concentration factor

BCF (l kg⁻¹)

Low potential

CT₅₀ (days)

1.4

Known soil metabolites

Metabolite

Major/Minor fraction

$Click here for further information on Major/Minor fraction$

Estimated maximum occurrence fraction

Notes

trinexapac (Ref: CGA 179500)

Major fraction

0.931

Syngenta verified

3-ethoxycarbonylpentanedioic acid (Ref: CGA 300405)

Major fraction

0.125

Syngenta verified

Known groundwater metabolites

None

Other known metabolites

Metabolite name and reference

Aliases

Formation medium / Rate

Estimated maximum occurrence fraction

Ref: CGA 351210

Plant

Ref: CGA 113745

Plant; Animal

Ref: CGA 275537

Plant

Ref: CGA 329773

Plant

ECOTOXICOLOGY

Terrestrial ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

4210

Rat

Low

Mammals - Short term dietary NOEL

(mg kg⁻¹)

> 34

Rat

High

(ppm diet)

> 500

Mammals - Chronic 21d NOAEL (mg kg⁻¹ bw d⁻¹)

≥ 1293

Rat Reproductive NOAEL

Low

Birds - Acute LD₅₀ (mg kg⁻¹)

> 2000

Anas platyrhynchos

Low

Birds - Short term dietary (LC₅₀/LD₅₀)

> 2000 mg kg feed⁻¹

Anas platyrhynchos

Birds - Chronic 21d NOEL (mg kg⁻¹ bw d⁻¹)

53.3

Colinus virginianus NOEL

Moderate

Earthworms - Acute 14 day LC₅₀ (mg kg⁻¹)

> 93

Eisenia foetida

Moderate

Earthworms - Chronic NOEC, reproduction (mg kg⁻¹)

Soil micro-organisms

Nitrogen mineralisation: No significant adverse effect
Carbon mineralisation: No significant adverse effect

Dose: 8.6 mg kg⁻¹ soil 28 Day

Collembola

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

25.2

Folsomia candida

Non-target plants

> 760

10 species including lettuce carrot oat onion
Vegetative vigour, ER₅₀
as g ha⁻¹

> 840

10 species including lettuce carrot oat onion
Seedling emergence, ER₅₀
as g ha⁻¹

Honeybees (Apis spp.)

Contact acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)

> 200

Apis mellifera

Low

Oral acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)

> 200

Apis mellifera

Low

Unknown mode acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)

Chronic as 10-day NOED µg bee⁻¹ day⁻¹

7.1

Apis mellifera

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) as Mortality LR₅₀ g ha⁻¹

> 400

Coccinella septempunctata Larva

Beneficial insects (Lacewings) as Mortality LR₅₀ g ha⁻¹

> 400

Chrysoperla carnea

Beneficial insects (Parasitic wasps) as Mortality LR₅₀ g ha⁻¹ 48 hr

114

Aphidius rhopalosiphi Adult

Beneficial insects (Predatory mites) as Mortality LR₅₀ g ha⁻¹ 7 day

197

Typhlodromus pyri Protonymph

Beneficial insects (Ground beetles)

3.3% Mortlity at 16 g ha⁻¹

Poecilus cupreus

Aquatic ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

Temperate Freshwater Fish - Acute 96 hour LC₅₀ (mg l⁻¹)

Ictalurus punctatus

Moderate

Temperate Freshwater Fish - Chronic 21 day NOEC (mg l⁻¹)

0.41

Pimephales promelas 35 day

Moderate

Tropical Freshwater Fish - Acute 96 hour LC₅₀ (mg l⁻¹)

Temperate Freshwater Aquatic invertebrates - Acute 48 hour EC₅₀ (mg l⁻¹)

> 142.5

Daphnia magna

Low

Temperate Freshwater Aquatic invertebrates - Chronic 21 day NOEC (mg l⁻¹)

2.4

Daphnia magna

Moderate

Tropical Freshwater Aquatic invertebrates - Acute 48 hour EC₅₀ (mg l⁻¹)

Aquatic crustaceans - Acute 96 hour LC₅₀ (mg l⁻¹)

5.8

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 (free-floating, growth) - Acute 7 day EC₅₀, biomass (mg l⁻¹)

8.8

Lemna gibba

Moderate

Aquatic plants (rooted, growth) - Acute 14 day EC₅₀, biomass (mg l⁻¹)

1,4

Myriophyllum picatum

Low

Algae - Acute 72 hour EC₅₀, growth (mg l⁻¹)

24.5

Pseudokirchneriella subcapitata 96 hr

Low

Algae - Chronic 96 hour NOEC, growth (mg l⁻¹)

Mesocosm study data

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)

4210

Rat

Low

Mammals - Dermal LD₅₀ (mg kg⁻¹ body weight)

4000

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

> 5.3

Rat 4 hr (nose only liquid aerosol)

Other Mammal toxicity endpoints

ADI - Acceptable Daily Intake (mg kg⁻¹ bw day⁻¹)

0.32

ARfD - Acute Reference Dose (mg kg⁻¹ bw day⁻¹)

None allocated

AAOEL - Acute Acceptable Operator Exposure Level (mg kg⁻¹ bw day⁻¹)

AOEL - Acceptable Operator Exposure Level - Systemic (mg kg⁻¹ bw day⁻¹)

0.34

Dermal penetration studies (%)

25-75

concentration dependent

Dangerous Substances Directive 76/464

Exposure Routes

Public

No unacceptable risks to bystanders identified

Occupational

No unacceptable risks to operators or other workers identified

MRLs

European

EU MRL pesticide database

Great Britain

GB MRL Register

Notes

Drinking Water Standards

Drinking Water MAC (μg l⁻¹)

0.1

EU Dir 89/778/EC limit; Calc MAC=42.0 µg l⁻¹

Mammalian dose elimination route and rate

Extensively metabolised, rapid excretion mainly via urine

Health issues

Specific human health issues

Carcinogen

Genotoxic

Endocrine disruptor

; ; ; ;

Reproduction / development effects

Acetyl cholinesterase inhibitor

Neurotoxicant

Respiratory tract irritant

Skin irritant

Skin sensitiser

Eye irritant

Phototoxicant

General human health issues

Liver, kidney and brain toxicant

Handling issues

Property

Value and interpretation

General

Not explosive or oxidising
Autoignition temperature >300 deg C
IMDG Transport Hazard Class 9

CLP classification 2013

Environment: H410, H411, H412

WHO Classification

III (Slightly hazardous)

UN Number

UN3077

Waste disposal & packaging

Packaging Group III (minor danger)

Shelf-life, storage, stability and reactivity

TRANSLATIONS

Language

Name

English

trinexapac-ethyl

French

trinexapac-ethyl

German

Trinexapac

Danish

trinexapac-ethyl

Italian

trinexapac-etile

Spanish

trinexapac-etil

Greek

Polish

trineksapak etylu

Swedish

trinexapak etylester

Hungarian

Dutch

trinexapac-ethyl

Norwegian

trineksapak-etyl

Record last updated:	25/05/2025
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