Cycloxydim (Ref: BAS 517H)

Cycloxydim (Ref: BAS 517H)	Last updated: 12/01/2021
(Also known as: cycloxydime; LAB 172 999)

SUMMARY

Cycloxydim is a systemic herbicide approved for use in the EU. It is moderately soluble in aqueous solution, is unlikely to leach to groudnwater and is relatively volatile. It is not persistent in soils and is unlikely to persist in aquatic systems due to rapid aqueous photolysis. It has a low mammalian toxicity and, whilst the chemical properties suggest it may bioaccumulate, that does not appear to happen in practice. It is a skin and eye irritant. It is moderately toxic to birds, honeybees, earthworms and aquatic invertebrates. However, its is not particularly toxic to fish and other aquatic organisms.

GENERAL INFORMATION

Description

A post-emergence foliar applied grass herbicide

Example pests controlled

Black grass; Volunteer cereals; Black bent; Onion couch

Example applications

Sugarbeet; Fodder beet; Mangels; Linseed; Vegetables including brassicas, beans, peas, leeks, carrots, swede; Fruit including strawberries; Potatoes

Efficacy & activity

Availability status

Current

Introduction & key dates

1989, France

UK regulatory status

UK COPR regulatory status

Approved

Date COPR inclusion expires

31/05/2024

UK LERAP status

None

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status

Approved

Dossier rapporteur/co-rapporteur

Netherlands/Denmark

Date EC 1107/2009 inclusion expires

31/05/2021

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
✓		✓	✓	✓	✓	✓	✓	✓

Also used in

Chemical structure

Isomerism

A chiral molecule existing in both the E- and the Z-forms depending on the polarity and the pH of the respective environment in which the molecule sits. The Z-isomer is predominate in acidic situations.

Chemical formula

C₁₇H₂₇NO₃S

Canonical SMILES

CCCC(=C1C(=O)CC(CC1=O)C2CCCSC2)NOCC

Isomeric SMILES

No data

International Chemical Identifier key (InChIKey)

GGWHBJGBERXSLL-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C17H27NO3S/c1-3-6-14(18-21-4-2)17-15(19)9-13(10-16(17)20)12-7-5-8-22-11-12/h12-13,19H,3-11H2,1-2H3/b18-14-

2D structure diagram/image available?

Yes

General status

Pesticide type

Herbicide

Substance group

Cyclohexanedione

Minimum active substance purity

940 g kg⁻¹

Known relevant impurities

EU dossier - None declared

Substance origin

Synthetic

Mode of action

Selective, systemic, absorbed by foliage. Inhibits fatty acid synthesis. An acetyl CoA carboxylase inhibitor (ACCase).

CAS RN

101205-02-1

EC number

405-230-9

CIPAC number

510

US EPA chemical code

PubChem CID

91765

Molecular mass

325.46

PIN (Preferred Identification Name)

(5E)-2-[(1E)-N-ethoxybutanimidoyl]-3-hydroxy-5-[(3E)-thian-3-yl]cyclohex-2-en-1-one

IUPAC name

(5RS)-2-[(EZ)-1-(ethoxyimino)butyl]-3-hydroxy-5-[(3RS)-thian-3-yl]cyclohex-2-en-1-one

CAS name

2-[1-(ethoxyimino)butyl]-3-hydroxy-5-(tetrahydro-2H-thiopyran-3-yl)-2-cyclohexen-1-one

Other status information

Relevant Environmental Water Quality Standards

Herbicide Resistance Classification (HRAC)

Herbicide Resistance Classification (WSSA)

Insecticide Resistance Classification (IRAC)

Not applicable

Fungicide Resistance Classification (FRAC)

Not applicable

Examples of recorded resistance

Alopecurus myosuroides, Avena sterilis

Physical state

Colourless crystals

Related substances & organisms

solvent naphtha

Formulations

Property

Value

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

Focus 10 EC
Laser
Focus Ultra
Stratos Ultra

Example products using this active

BASF
Greencrop
Teliton

Formulation and application details

Often supplied as an emulsion concentrate which is mixed with water and applied as a spray to dry foliage

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

Moderate

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

250000

Acetone

810000

Ethanol

29000

Hexane

250000

Ethyl acetate

Melting point (°C)

37.1

Boiling point (°C)

Decomposes before boiling

Degradation point (°C)

200

Flashpoint (°C)

Not expected to self ignite; Not highly flammable

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

2.29 X 10⁰¹

Calculated

Log P

1.36

Low

Bulk density (g ml⁻¹)

1.12

Dissociation constant pKa) at 25 °C

4.17

Weak acid

Vapour pressure at 20 °C (mPa)

0.01

Low volatility

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

6.14 X 10^-05

Non-volatile

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

Neutral solution: >290nm = 10
Methanol: 210nm = 7200, 227nm = 4100, 259nm = 1000, 278nm = 9300, 290nm = 7900, 300nm = 4400

Surface tension (mN m⁻¹)

58.0

at 20°C 0.5%w/w

Degradation

Property

Value

Source; quality score; and other information

Interpretation

General biodegradability

Soil degradation (days) (aerobic)

DT₅₀ (typical)

0.65

Non-persistent

DT₅₀ (lab at 20 °C)

0.65

Non-persistent

DT₅₀ (field)

Non-persistent

DT₉₀ (lab at 20 °C)

3.47

Non-persistent

DT₉₀ (field)

DT₅₀ modelling endpoint

Note

EU Dossier lab studies DT₅₀ range 0.2-2.6 days, DT₉₀ range 0.5-8.6 days; Other lab studies DT₅₀ 1-12 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

0.05

Fast

Note

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

Value

172

Persistent

Note

pH sensitive: DT₅₀ 1.7 days at pH 3, 8.3 days at pH 5, 172 days at pH 7, 206 days at pH 9 all at 24 °C

Water-sediment DT₅₀ (days)

20.8

Fast

Water phase only DT₅₀ (days)

4.5

Moderately fast

Soil adsorption and mobility

Property

Value

Source; quality score; and other information

Interpretation

Linear

K_d

0.38

Mobile

K_oc

Notes and range

EU dossier K_d range 0.03-0.73 mL g⁻¹, K_oc range 5-183 mL g⁻¹, Soils=4; Other studies 5-185 mL g⁻¹

Freundlich

K_f

K_foc

¹/_n

Notes and range

pH sensitivity

None but little adsorption observed on soils pH >6

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

1.56

Calculated

Low leachability

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

Value

4.19 X 10^-03

Calculated

Note

Potential for particle bound transport index

Low

Calculated

Potential for loss via drain flow

Mobile

Calculated

Key metabolites

Metabolite

Formation medium

Estimated maximum occurrence fraction

1107/2009 relevancy

cycloxydim sulfoxide (Ref: BH 517-TSO)

Soil

0.904

Major fraction, Relevant

cycloxydim sulfone (Ref: BH 517-TSO2)

Soil

0.095

Minor fraction, Relevant

Other known metabolites

Metabolite name and reference

Aliases

Formation medium / Rate

Estimated maximum occurrence fraction

Metabolising enzymes

2-butanimidoyl-3-hydroxy-5-(tetrahydro-2H-thiopyran-3-yl)cyclohex-2-en-1-one (Ref: BH 517-T1S)
Note: Low aquatic toxicity

Water; Sediment; Animal

2-butanimidoyl-3-hydroxy-5-(1-oxidotetrahydro-2H-thiopyran-3-yl)cyclohex-2-en-1-one (Ref: BH 517-T1SO)
Note: Low aquatic toxicity

Animal; Water; Sediment

2-propyl-6-(3-thianyl)-4,5,6,7-tetrahydrobenzoxazol-4-one S-dioxide (Ref: BH 517-T2SO2)
Note: Risk to groundwater

cycloxydim oxazole metabolite

Plant; Soil

3-(1-oxidotetrahydro-2H-thiopyran-3-yl)pentanedioic acid (Ref: BH 517-TGSO)

Plant; Soil

3-(3-thianyl)glutaric acid S- dioxide (Ref: BH 517-TGSO2)

Plant

3-hydroxy-3-(3-thianyl)glutaric acid S-dioxide (Ref: BH 517-OH-TGSO2)

Plant

2-butanimidoyl-5-(1,1-dioxidotetrahydro-2H-thiopyran-3-yl)-3-hydroxycyclohex-2-en-1-one (Ref: BH 517-T1SO2)

Plant

2-[1-(ethoxyimino)butyl]-3,5-dihydroxy-5-(3-thianyl)-2-cyclohexen-1-one (Ref: BH 517-5-OH TS)

Plant

2-[1-(ethoxyimino)butyl]-3,5-dihydroxy-5-(3-thianyl)-2-cycloexene-1-one S-oxide (Ref: BH 517-5-OH-TSO)

Plant

2-[1-(ethoxyimino)butyl]-3,5-dihydroxy-5-(3-thianyl)-2-cycloexene-1-one S-dioxide (Ref: BH 517-5-OH-TSO2)

Plant

Ref: BH 517-6-OH-T2SO

Plant

2-propyl-6-(3-thianyl)-4,5,6,7-tetrahydrobenzoxazol-4-one (Ref: BH 517-T2S)

cycloxydim oxazole metabolite

Plant; Water

ECOTOXICOLOGY

Property

Value

Source; quality score; and other information

Interpretation

Bio-concentration factor

BCF (l kg⁻¹)

Low risk

Based on LogP < 3

Low risk

CT₅₀ (days)

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

3940

Rat

Low

Mammals - Short term dietary NOEL

(mg kg⁻¹)

> 10

Dog

High

(ppm diet)

> 300

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

129

Unknown species Reproductive NOAEL

Moderate

Birds - Acute LD₅₀ (mg kg⁻¹)

> 2000

Colinus virginianus

Low

Birds - Short term dietary (LC₅₀/LD₅₀)

496.8 mg kg bw⁻¹ day⁻¹

Colinus virginianus

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

65.4

Colinius virginianus

Moderate

Fish - Acute 96 hour LC₅₀ (mg l⁻¹)

> 220

Oncorhynchus mykiss

Low

Fish - Chronic 21 day NOEC (mg l⁻¹)

21.5

Oncorhynchus mykiss

Low

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

> 70.8

Daphnia magna

Moderate

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

62.5

Daphnia magna

Low

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 - Acute 7 day EC₅₀, biomass (mg l⁻¹)

> 100

Lemna gibba

Low

Non-target plants

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

> 74.9

Anabaena flos-aquae

Low

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

Unknown species

Low

Honeybees (Apis spp.)

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

> 100

Apis mellifera

Low

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

> 101.7

Apis mellifera

Low

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

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

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

> 500

Eisenia foetida corr

Moderate

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

Other soil macro-organisms

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

Other arthropod (1)

LR₅₀ g ha⁻¹

% Effect

0 / 23.3

Mortality / Reproduction [Dose: 0.6 kg ha⁻¹]
Aphidius rhopalosiphi adult

Other arthropod (2)

LR₅₀ g ha⁻¹

% Effect

19.6 / 6.1

Mortality / Reproduction [Dose: 0.6 kg ha⁻¹]
Typhlodromus pyri protonymph

Soil micro-organisms

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

Dose: 2.5 kg ha⁻¹ 28 days

Mesocosm study data

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)

3940

Rat

Low

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

2000

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

> 5.28

Rat 4 hr (nose only)

Other Mammal toxicity endpoints

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

0.07

Rat SF=100

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

2.0

Rat SF=100

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

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

0.1

Dog SF=100

Dermal penetration studies (%)

Dangerous Substances Directive 76/464

Exposure Routes

Public

Negligible risk to bystanders

Occupational

PPE/PPC recommended

MRLs

European

EU MRL pesticide database

Notes

Drinking Water Standards

Drinking Water MAC (μg l⁻¹)

Health issues

Specific human health issues

Carcinogen

Genotoxic

Endocrine disruptor

; ; ; ;

No data found

Reproduction / development effects

Acetyl cholinesterase inhibitor

Neurotoxicant

Respiratory tract irritant

Skin irritant

Skin sensitiser

No data found

Eye irritant

Phototoxicant

No data found

General human health issues

No further information available

Handling issues

Property

Value and interpretation

General

Flammable
Not explosive or oxidising
IMDG Transport Code is usually 9

CLP classification 2013

Health: H361d

EC Risk Classification

Reproduction risk category 3: R63
H - Handling risks: R11
N - Dangerous for the environment: R53

EC Safety Classification

S1/2, S13, S20/21, S36/37

WHO Classification

III (Slightly hazardous)

UN Number

Usually 3082

Waste disposal & packaging

Packaging Group III (minor danger)

TRANSLATIONS

Language

Name

English

cycloxydim

French

cycloxydime

German

Cycloxydim

Danish

cycloxydim

Italian

cicloxidim

Spanish

cicloxidim

Greek

Polish

cykloksydym

Swedish

cykloxidim

Hungarian

cikloxidim

Dutch

cycloxydim

Record last updated:	12/01/2021
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