Carboxin (Ref: D 735)

Carboxin (Ref: D 735)	Last updated: 29/05/2025
(Also known as: carboxine; carbathiin; vitavax)

SUMMARY

Carboxin is an effective agricultural fungicide. It is moderately soluble in water, is non-volatile and, based on its chemical properties, would not normally be expected to leach to groundwater. It tends not to persist in soil or water systems. Whilst it is an irritant, its mammalian toxicity is low and no significant health effects have been identified. It shows a low or moderate ecotoxicity to most species.

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 acute ecotoxicity: Moderate; Daphnia chronic ecotoxicity: Moderate; Earthworms acute ecotoxicity: Moderate; Earthworms chronic ecotoxicity: Moderate	Human health Moderate alert: Mammals chronic toxicity: Moderate; Genotoxic; Reproduction/development effects

GENERAL INFORMATION

Description

An anilide fungicide for bunts and smuts normally that is normally used as a seed treatment

Example pests controlled

Smut; Rots; Bunt; Blight; Leaf stripe; Net blotch

Example applications

Rice; Vegetables; Corn; Wheat; Barley; Oats; Turf grass; Cotton

Efficacy & activity

Carboxin has been shown to be an effective fungicide via field trials and long use globally.

Availability status

Current

Introduction & key dates

1966, first reported; 1969, first introduced

GB regulatory status

GB COPR regulatory status

Not approved

Date COPR inclusion expires

Withdrawn

GB LERAP status

No data

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status

Not approved

Dossier rapporteur/co-rapporteur

Croatia/Latvia

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

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; USA

Chemical structure

Isomerism

None

Chemical formula

C₁₂H₁₃NO₂S

Canonical SMILES

CC1=C(SCCO1)C(=O)NC2=CC=CC=C2

Isomeric SMILES

No data

International Chemical Identifier key (InChIKey)

GYSSRZJIHXQEHQ-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C12H13NO2S/c1-9-11(16-8-7-15-9)12(14)13-10-5-3-2-4-6-10/h2-6H,7-8H2,1H3,(H,13,14)

2D structure diagram/image available?

Yes

Cambridge Crystallographic Data Centre diagrams

Common Name	Relationship	Link
carboxin	-

General status

Pesticide type

Fungicide

Substance groups

Oxathiin fungicide; Anilide fungicide

Minimum active substance purity

970 g kg⁻¹

Known relevant impurities

EU dossier - None declared

Substance origin

Synthetic

Mode of action

Systemic, inhibits mitochondrial function. Succinate Dehydrogenase Inhibitor.

CAS RN

5234-68-4

EC number

226-031-1

CIPAC number

273

US EPA chemical code

090201

PubChem CID

21307

CLP index number

616-226-00-3

Molecular mass

235.30

PIN (Preferred Identification Name)

2-methyl-N-phenyl-5,6-dihydro-1,4-oxathiine-3-carboxamide

IUPAC name

5,6-dihydro-2-methyl-1,4-oxathiine-3-carboxanilide

CAS name

5,6-dihydro-2-methyl-N-phenyl-1,4-oxathiin-3-carboxamide

Other status information

PAN Bad Actor Chemical

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)

Examples of recorded resistance

Physical state

Off-white coloured crystals

Formulations

Property

Value

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

Chemtura Corp
Crompton Europe
Bayer CropScience
Uniroyal
BOC Sciences

Example products using this active

Vitavax 200FF
Krisvax
Kemikar
Cotguard
Enhance

Formulation and application details

Usually formulated as a flowable concentrate that is diluted with water for use as a seed treatment

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

134

Moderate

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

220000

Acetone

110000

Ethyl acetate

89000

Methanol

53000

Toluene

Melting point (°C)

91.5

Boiling point (°C)

Decomposes before boiling

Degradation point (°C)

210

Flashpoint (°C)

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

2.00 X 10⁰²

Calculated

Log P

2.3

Low

Fat solubility of residues

Solubility

Data type

Density (g ml⁻¹)

1.45

Dissociation constant pKa) at 25 °C

0.5

Strong acid

Vapour pressure at 20 °C (mPa)

0.02

Low volatility

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

3.20 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

205nm = 17443, 295nm = 6585

Surface tension (mN m⁻¹)

61.2

at 20°C

Degradation

Property

Value

Source; quality score; and other information

Interpretation

General biodegradability

Soil degradation (days) (aerobic)

DT₅₀ (typical)

0.5

Non-persistent

DT₅₀ (lab at 20 °C)

0.28

Non-persistent

DT₅₀ (field)

3.3

Non-persistent

DT₉₀ (lab at 20 °C)

1.99

Non-persistent

DT₉₀ (field)

11.1

DT₅₀ modelling endpoint

Note

EU dossier Lab studies DT₅₀ range 0.07-1.68 days, DT₉₀ range 0.23-3.49 days; field studies DT₅₀ range 0.27-11 days, DT₉₀ range 0.9-37 days; Other sources: DT₅₀ 1 day (R3)

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

0.1

Fast

Note

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

Value

Stable

Note

Stable between pH 4 and pH 9

Water-sediment DT₅₀ (days)

17.3

Fast

Water phase only DT₅₀ (days)

13.6

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)

1.3

Moderately mobile

K_oc (mL g⁻¹)

99.4

Notes and range

EU dossier K_d range 1.03-1.78 mL g⁻¹, K_oc range 81-124 mL g⁻¹, Soils=5

Freundlich

K_f (mL g⁻¹)

1.95

Very mobile

K_foc (mL g⁻¹)

1.3

¹/_n

0.80

Notes and range

EU dossier K_f range 1.56-2.71 mL g⁻¹, K_foc range 123-213 mL g⁻¹, ¹/_n range 0.79-0.81, Soils=5

pH sensitivity

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

2.01

Calculated

Transition state

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

Value

3.83 X 10^-03

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

1.9

Calculated using the Atkinson method. Assumed 5.0E+05 OH/cm³

Below the level of concern for long-range air transport

Bio-concentration factor

BCF (l kg⁻¹)

Estimated

Low potential

CT₅₀ (days)

Not available

Known soil metabolites

Metabolite

Major/Minor fraction

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

Estimated maximum occurrence fraction

Notes

carboxin sulfoxide

Major fraction

0.782

oxycarboxin (Ref: F 461)

Major fraction

0.170

oxathiine amide sulfoxide

Major fraction

0.274

oxathiine amide sulfone

Major fraction

0.145

2-[2-anilino-2-oxoacetyl)thio]ethyl acetate (Ref: M6)

Major fraction

0.101

2-hydroxy-2-methyl-N-phenyl-1,4-oxathiane-3-carboxamide-4-oxide (Ref: M9)

Minor fraction

0.069

Known groundwater metabolites

Metabolite

EC SANCO/221/2000 relevancy

ADI (mg kg⁻¹ bodyweight day⁻¹)

WHO drinking water guidance value (μg L⁻¹ day⁻¹)

2-[2-anilino-2-oxoacetyl)thio]ethyl acetate (Ref: M6)

Relevant

2-hydroxy-2-methyl-N-phenyl-1,4-oxathiane-3-carboxamide-4-oxide (Ref: M9)

Relevant

2-methyl-5,6-dihydro-1,4-oxathiine-3-carboxamide-4-oxide (Ref: P/V-54)

Relevant

2-methyl-5,6-dihydro-1,4-oxathiine-3-carboxamide 4,4-dioxide (Ref: P/V-55)

Relevant

Other known metabolites

Metabolite name and reference

Aliases

Formation medium / Rate

Estimated maximum occurrence fraction

2-[2-anilino-2-oxoacetyl)thio]ethyl acetate

Surface water

2-hydroxy-2-methyl-N-phenyl-1,4-oxathiane-3-carboxamide-4-oxide

Surface water

2-methyl-5,6-dihydro-1,4-oxathiine-3-carboxylic acid-4-oxide (Ref: 2138)

Surface water

4-O-glucuronyl carboxin sulfoxide

Rat (Urine & Bile)

4-hydroxycarboxin sulfoxide

Rat (Urine & Bile)

acetanilide

Plant

4-hydroxycarboxin sulfone

Rat (Urine & Bile)

4-O-glucuronyl-2-hydroxycarboxin

Rat (Urine)

4-hydroxycarboxin

Rat (Urine, Faeces & Bile)

monomethoxy dihydroxycarboxin

Rat (Urine & Faeces)

2-methoxycarboxin sulfoxide-4-glucuronide

Rat (Bile & Urine)

4-O-glucuronyl carboxin

Rat (Bile)

ECOTOXICOLOGY

Terrestrial ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

2588

Rat

Low

Mammals - Short term dietary NOEL

(mg kg⁻¹)

5.5

Rat

High

(ppm diet)

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

Rat Reproductive NOAEL

Moderate

Birds - Acute LD₅₀ (mg kg⁻¹)

> 2150

Colinus virginianus

Low

Birds - Short term dietary (LC₅₀/LD₅₀)

> 5000 mg kg feed⁻¹

Colinus virginianus

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

Colinus virginianus

Moderate

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

> 250

Eisenia foetida

Moderate

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

Eisenia foetida

Moderate

Soil micro-organisms

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

Dose: 660 g ha⁻¹

Collembola

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

Non-target plants

Honeybees (Apis spp.)

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

181

Apis mellifera

Low

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

> 100

Apis mellifera

Low

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)

0% Mortality

Poecilus cupreus

Aquatic ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

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

2.3

Oncorhynchus mykiss

Moderate

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

0.32

Cyprinidae

Moderate

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

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

> 57

Daphnia magna

Moderate

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

0.32

Daphnia magna 17 day

Moderate

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

> 2.09

Ceriodaphnia dubia

Moderate

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

0.92

Lemna gibba

Moderate

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

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

0.48

Pseudokirchneriella subcapitata

Moderate

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)

2588

Rat

Low

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

4000

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

> 4.7

Rat 4 hr

Other Mammal toxicity endpoints

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

0.008

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

None allocated

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

Not applicable

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

0.055

Dermal penetration studies (%)

3.3-5.0

concentration dependent

Dangerous Substances Directive 76/464

Exposure Routes

Public

Negligible risk to the public due to pattern of use

Occupational

Acceptable risks with PPE/PPC

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=4.8 µg l⁻¹

Mammalian dose elimination route and rate

Health issues

Specific human health issues

Carcinogen

Genotoxic

Endocrine disruptor

; ; ; ;

No data found

Reproduction / development effects

Acetyl cholinesterase inhibitor

Neurotoxicant

No data found

Respiratory tract irritant

Skin irritant

Skin sensitiser

No data found

Eye irritant

Phototoxicant

No data found

General human health issues

Mild skin sensitiser
Possible kidney toxicant

Handling issues

Property

Value and interpretation

General

Not explosive or oxidising
Not expected to auto-ignite; Not highly flammable

CLP classification 2013

Health: H302, H312, H317, H332, H373; Environment: H400, H410

WHO Classification

III (Slightly hazardous)

UN Number

Waste disposal & packaging

Shelf-life, storage, stability and reactivity

Limited shelf-life. Store at -20 DegC

TRANSLATIONS

Language

Name

English

carboxin

French

carboxine

German

Carboxin

Danish

carboxin

Italian

carbossina

Spanish

carboxina

Greek

carboxin

Polish

karboksyna

Swedish

karboxin

Hungarian

karboxin

Dutch

carboxin

Norwegian

Record last updated:	29/05/2025
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