Sethoxydim (Ref: BAS 9052H)

Sethoxydim (Ref: BAS 9052H)	Last updated: 24/06/2021
(Also known as: sethoxydime; cyethoxydim; NP 55)

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: Drainflow: Moderately mobile	Ecotoxicity Moderate alert: Fish chronic ecotoxicity: Moderate; Daphnia acute ecotoxicity: Moderate; Bees acute contact ecotoxicity: Moderate; Earthworms acute ecotoxicity: Moderate	Human health Low alert

GENERAL INFORMATION

Description

A post-emergence, selective, annual and perennial grass weed herbicide

Example pests controlled

Barnyardgrass; Crabgrass; Cupgrass; Foxtail; Tall fescue; Johnsongrass; Junglerice; Tame oats; Itchgrass; Volunteer cereals; Stinkgrass

Example applications

Alfalfa; Citrus; Sorghum; Corn; Small grains; Rice; Ornamental grass; Oilseed rape; Sugarbeet; Vegetables

Efficacy & activity

Availability status

Current

Introduction & key dates

1983, Introduced USA

UK regulatory status

UK COPR regulatory status

Not approved

Date COPR inclusion expires

Expired

UK LERAP status

No UK approval for use

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

Expired

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

Additional information

Also used in

Australia

Chemical structure

Isomerism

A chiral molecule

Chemical formula

C₁₇H₂₉NO₃S

Canonical SMILES

CCCC(=C1C(=O)CC(CC1=O)CC(C)SCC)NOCC

Isomeric SMILES

No data

International Chemical Identifier key (InChIKey)

CSPPKDPQLUUTND-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C17H29NO3S/c1-5-8-14(18-21-6-2)17-15(19)10-13(11-16(17)20)9-12(4)22-7-3/h12-13,19H,5-11H2,1-4H3/b18-14+

2D structure diagram/image available?

Yes

General status

Pesticide type

Herbicide

Substance group

Cyclohexadione

Minimum active substance purity

Known relevant impurities

Substance origin

Synthetic

Mode of action

Selective, systemic absorbed mainly by foliage. An acetyl CoA carboxylase inhibitor (ACCase).

CAS RN

74051-80-2

EC number

277-682-3

CIPAC number

401

US EPA chemical code

121001

PubChem CID

52923

Molecular mass

327.48

PIN (Preferred Identification Name)

(5E)-2-[(1E)-N-ethoxybutanimidoyl]-5-[(2E)-2-(ethylsulfanyl)propyl]-3-hydroxycyclohex-2-en-1-one

IUPAC name

(5RS)-2-[(EZ)-1-(ethoxyimino)butyl]-5-[(2RS)-2-(ethylthio)propyl]-3-hydroxycyclohex-2-en-1-one

CAS name

2-(1-(ethoxyimino)butyl)-5-(2-(ethylthio)propyl)-3-hydroxy-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

Many recorded cases, Alopecurus myosuroides, Avena fatua, Avena sterilis, Avena sterilis ludoviciana, Digitaria sanguinalis

Physical state

Oily amber liquid

Related substances & organisms

naphtha

acifluorfen

bentazone

Formulations

Property

Value

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

BASF
Bayer CropScience
Nippon Soda

Example products using this active

Conclude
Headline G
Poast
NABU

Formulation and application details

Usually supplied as an emulsifiable concentrate.

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

4700

High

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

Melting point (°C)

Not applicable

Boiling point (°C)

Degradation point (°C)

Flashpoint (°C)

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

4.47 X 10⁰¹

Calculated

Log P

1.65

Low

Bulk density (g ml⁻¹)

1.043

Dissociation constant pKa) at 25 °C

4.58

Weak acid

Vapour pressure at 20 °C (mPa)

0.013

Low volatility

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

1.39 X 10^-06

Non-volatile

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)

1.2

Non-persistent

DT₅₀ (lab at 20 °C)

Non-persistent

DT₅₀ (field)

Non-persistent

DT₉₀ (lab at 20 °C)

DT₉₀ (field)

DT₅₀ modelling endpoint

Note

Other sources: DT₅₀ 5-25 days (Q3), 1 day sandy soils (R3)

Dissipation rate RL₅₀ on plant matrix

Value

Note

Dissipation rate RL₅₀ on and in plant matrix

Value

0.04

Note

Navy bean leaves, n=1

Aqueous photolysis DT₅₀ (days) at pH 7

Value

0.02

Fast

Note

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

Value

242

Persistent

Note

Water-sediment DT₅₀ (days)

130

Slow

Water phase only DT₅₀ (days)

17.8

Slow

Soil adsorption and mobility

Property

Value

Source; quality score; and other information

Interpretation

Linear

K_d

Moderately mobile

K_oc

Notes and range

Literature values indicate little adsorption with values typicaly between 50 and 100 ml/g

Freundlich

K_f

K_foc

¹/_n

Notes and range

pH sensitivity

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

1.49

Calculated

Low leachability

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

Value

4.15 X 10^-03

Calculated

Note

Potential for particle bound transport index

Low

Calculated

Potential for loss via drain flow

Moderately mobile

Calculated

Key metabolites

Metabolite

Formation medium

Estimated maximum occurrence fraction

1107/2009 relevancy

sethoxydim-sulfoxide

Soil

0.560

Major fraction

6-(2-ethylsulfinylpropyl)-4-oxy-2-propyl-4,5,6,7-tetrahydro-1,3,benzoxazole

Soil

0.190

Major fraction

ECOTOXICOLOGY

Property

Value

Source; quality score; and other information

Interpretation

Bio-concentration factor

BCF (l kg⁻¹)

22.5

Whole fish

Low potential

CT₅₀ (days)

Not available

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

2676

Rat

Low

Mammals - Short term dietary NOEL

(mg kg⁻¹)

17.2

Rat 2 year

High

(ppm diet)

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

Birds - Acute LD₅₀ (mg kg⁻¹)

> 5000

Coturnix japonica

Low

Birds - Short term dietary (LC₅₀/LD₅₀)

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

Fish - Acute 96 hour LC₅₀ (mg l⁻¹)

> 170

Oncorhynchus mykiss

Low

Fish - Chronic 21 day NOEC (mg l⁻¹)

0.18

Lepomis macrochirus 4 day

Moderate

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

> 1.5

Daphnia magna

Moderate

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

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

> 0.700

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 - Acute 7 day EC₅₀, biomass (mg l⁻¹)

0.28

Lemna gibba

Moderate

Non-target plants

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

0.64

Unknown species

Moderate

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

Honeybees (Apis spp.)

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

> 10

Moderate

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)

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)

> 542

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

Moderately harmful

[Dose: 3160 g ha⁻¹]
Typhlodromus pyri

Other arthropod (2)

LR₅₀ g ha⁻¹

% Effect

Harmless

[Dose: 3160 g ha⁻¹]
Chrysoperla carnea

Soil micro-organisms

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)

2676

Rat

Low

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

5000

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

6.28

Rat 4 hr

Other Mammal toxicity endpoints

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

0.14

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

May be absorbed through the skin

MRLs

European

EU MRL pesticide database

Great Britain

GB MRL Register

Notes

GB MRL levels for some commodities subject to change in late 2021

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

Possible thyroid, liver and bone marrow toxicant
May cause lung damage if swallowed

Handling issues

Property

Value and interpretation

General

No information available

CLP classification 2013

Not classified: Obsolete

EC Risk Classification

Xn - Harmful: R65
N - Dangerous for the environment: R51/53

EC Safety Classification

WHO Classification

III (Slightly hazardous)

UN Number

Waste disposal & packaging

TRANSLATIONS

Language

Name

English

sethoxydim

French

séthoxydime

German

Sethoxydim

Danish

sethoxydim

Italian

setossidim

Spanish

setoxidim

Greek

Polish

setoksydim

Swedish

Hungarian

Dutch

setoxidim

Record last updated:	24/06/2021
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