Butroxydim (Ref: ICIA0500)

Butroxydim (Ref: ICIA0500)	Last updated: 29/08/2025
(Not known by any other names)

SUMMARY

Butroxydim is an obsolete herbicide. It has a low aqueous solubility, is relatively volatile and, based on its chemical properties, is non-mobile and would not be expected to leach to groundwater. It is generally non-persistent in soil systems but may persist in aquatic systems under certain conditions. It is not generally susceptible to hydrolysis. It has a moderate mammalian toxicity and has a high potential to bioaccumulate. It is moderately toxic to most aquatic species, birds and earthworms but relatively non-toxic to honeybees.

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
Environmental fate Moderate alert: Drainflow: Slightly mobile Warning: Significant data are missing	Ecotoxicity Moderate alert: Birds acute ecotoxicity: Moderate; Fish acute ecotoxicity: Moderate; Daphnia acute ecotoxicity: Moderate; Earthworms acute ecotoxicity: Moderate	Human health Moderate alert: Mammals acute toxicity: Moderate; Reproduction/development effects

GENERAL INFORMATION

Description

Used for the control of Digitaria spp. and other grass species in soya and other broad leaved crops.

Example pests controlled

Annual ryegrass; Barley grass; Wild oats; Brome grass; Velvetgrass; Crabgrass; Barnyardgrass; Johnsson grass

Example applications

Soybeans; vegetables including peas, beans, chickpeas, lentils; Linseed; Lucerne; Lupins; Vetches; Cotton; sunflowers

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

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

Chemical structure

Isomerism

Butroxydim exhibits geometrical (E/Z) isomerism due to the presence of a ketoxime functional group in its structure. Specifically, the molecule contains a cyclohexane-1,3-dione ring substituted with a propylidene oxime side chain, which can exist in either the E (trans) or Z (cis) configuration depending on the spatial orientation of the ethoxyamino group relative to the rest of the molecule. In commercial formulations, butroxydim is typically used as a mixture of isomers, although the E-isomer is generally considered more biologically active.

Chemical formula

C₂₄H₃₃NO₄

Canonical SMILES

CCCC(=O)C1=C(C(=C(C=C1C)C)C2CC(=O)C(=C(CC)NOCC)C(=O)C2)C

Isomeric SMILES

No data

International Chemical Identifier key (InChIKey)

LQNKITCRDAZSGT-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C24H33NO4/c1-7-10-19(26)23-15(5)11-14(4)22(16(23)6)17-12-20(27)24(21(28)13-17)18(8-2)25-29-9-3/h11,17,27H,7-10,12-13H2,1-6H3

2D structure diagram/image available?

Yes

General status

Pesticide type

Herbicide

Substance groups

Cyclohexene oxime herbicide

Minimum active substance purity

Known relevant impurities

Substance origin

Synthetic

Mode of action

Selective and systemic. Absorbed by leaves and translocated. Acetyl CoA carboxylase inhibitor (ACCase) - distrupts fatty acid biosynthesis and lipid formation.

CAS RN

138164-12-2

EC number

414-790-3

CIPAC number

None allocated

US EPA chemical code

Not listed

PubChem CID

butroxydim

CLP index number

606-070-00-4

Molecular mass

399.53

PIN (Preferred Identification Name)

(5E)-5-(3-butanoyl-2,4,6-trimethylphenyl)-2-[(1E)-N-ethoxypropanimidoyl]-3-hydroxycyclohex-2-en-1-one

IUPAC name

(5RS)-5-(3-butyryl-2,4,6-trimethylphenyl)-2-[(EZ)-1-(ethoxyimino)propyl]-3-hydroxycyclohex-2-en-1-one

CAS name

2-[1-(ethoxyimino)propyl]-3-hydroxy-5-[2,4,6-trimethyl-3-(1-oxobutyl)phenyl]-2-cyclohexen-1-one

Forever chemical

Other status information

Relevant Environmental Water Quality Standards

Herbicide Resistance Class (HRAC MoA class)

Herbicide Resistance Class (WSSA MoA class)

Insecticide Resistance Class (IRAC MoA class)

Not applicable

Fungicide Resistance Class (FRAC MOA class)

Not applicable

Examples of recorded resistance

Brachiaria plantaginea

Physical state

Dirty white powdery soild

Commercial

Property

Value

Availability status

Considered obsolete but may be available in some countries

Introduction & key dates

1995, first marketed

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

Crop Care
Shandong Rainbow International Co Ltd

Example products using this active

Fusion Super WG herbicide
Factor
Falcon
Dimrock

Formulation and application details

Usually supplied as water-dispersible granules or emulsifiable concentrates

Commercial production

The production of butroxydim involves synthesising a cyclohexane-1,3-dione core, which serves as the backbone for its herbicidal activity. The process begins with constructing the substituted aromatic ring, typically a 3-butanoyl-2,4,6-trimethylphenyl group, through Friedel–Crafts acylation and methylation reactions. This aromatic moiety is then coupled to the cyclohexanedione ring via condensation, forming a stable enone intermediate. Next, the key oxime ether side chain is introduced by reacting the enone with ethoxyamine, yielding the biologically active ketoxime structure.

Impact on climate of production and use

Data for the amount of life cycle GHGs produced by butroxydim are not available in the public domain. However, whilst estimates vary, more general data suggests that between 18 and 27 kilograms of CO₂e is emitted per kilogram of herbicide produced.

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

6.9

Low

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

500000

Dichloromethane

450000

Acetone

90000

Methanol

30000

Hexane

Melting point (°C)

80.0

Boiling point (°C)

Degradation point (°C)

Flashpoint (°C)

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

7.94 X 10⁰¹

Calculated

Log P

1.9

Low

Fat solubility of residues

Solubility

Data type

Density (g ml⁻¹)

1.2

Dissociation constant pKa) at 25 °C

4.36

Weak acid

Vapour pressure at 20 °C (mPa)

0.001

Low volatility

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

5.79 X 10^-05

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)

Non-persistent

DT₅₀ (lab at 20 °C)

DT₅₀ (field)

DT₉₀ (lab at 20 °C)

DT₉₀ (field)

DT₅₀ modelling endpoint

Note

Best available data

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

Note

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

Value

240

Persistent

Note

pH sensitive: Stable pH 7 to pH 9, DT₅₀: 10.5 days at pH 5

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

K_d (mL g⁻¹)

Slightly mobile

K_oc (mL g⁻¹)

635

Notes and range

Literature values range 6-1270 mL g⁻¹

Freundlich

K_f (mL g⁻¹)

K_foc (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

1.14

Calculated

Low leachability

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

Value

1.41 X 10^-02

Calculated

Note

Potential for particle bound transport index

Low

Calculated

Potential for loss via drain flow

Slightly mobile

Calculated

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

Bio-concentration factor

BCF (l kg⁻¹)

Low risk

Based on LogP < 3

Low risk

CT₅₀ (days)

Known metabolites

None

ECOTOXICOLOGY

Terrestrial ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

1635

Rat

Moderate

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

Anas platyrhynchos

Moderate

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

Eisenia foetida

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

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)

200

Low

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)

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)

6.9

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)

3.7

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)

Aquatic plants (rooted, growth rate, fresh) - 14 day (mg l⁻¹)

Algae - Acute (growth rate, fresh; mg l⁻¹) (EC₅₀)

0.71

Raphidocelis subcapitata

Moderate

Algae - Chronic (growth rate, fresh; 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)

1635

Rat

Moderate

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

2000

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

2.99

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)

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

Carcinogen

Genotoxic

Endocrine disruptor

No data found

; ; ; ;

No data found

Reproduction / development effects

Acetyl cholinesterase inhibitor

Neurotoxicant

Respiratory tract irritant

Skin irritant

Skin sensitiser

Eye irritant

Phototoxicant

No data found

General human health issues

No further information available

Handling issues

Property

Value and interpretation

General

No information available

CLP classification 2013

Health: H302, H315, H361fd
Environment: H400, H410

WHO Classification

II (Moderately hazardous)

UN Number

Waste disposal & packaging

Shelf-life, storage, stability and reactivity

TRANSLATIONS

Language

Name

English

butroxydim

French

German

Danish

Italian

Spanish

Greek

Polish

butroksydym

Swedish

Hungarian

Dutch

Norwegian

Record last updated:	29/08/2025
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