Cymoxanil (Ref: DPX T3217)

Cymoxanil (Ref: DPX T3217)	Last updated: 26/05/2025
(Also known as: cimoxanil)

SUMMARY

Cymoxanil is a fungicide that is moderately soluble in water and considered quite volatile. It has a low potential for leaching to groundwater, is non-persistent in soil and water systems. Cymoxanil is moderately toxic to mammals, may cause adverse effects on reproduction/development and has a high potential to bio-concentrate. It is moderately toxic to most aquatic organisms, earthworms and honeybees but less so to birds.

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 High alert: Drainflow: Mobile	Ecotoxicity Moderate alert: Birds acute ecotoxicity: Moderate; Birds chronic ecotoxicity: Moderate; Fish acute ecotoxicity: Moderate; Fish chronic ecotoxicity: Moderate; Daphnia acute ecotoxicity: Moderate; Daphnia chronic ecotoxicity: Moderate; Bees acute oral ecotoxicity: Moderate; Earthworms chronic ecotoxicity: Moderate	Human health Moderate alert: Mammals acute toxicity: Moderate; Mammals chronic toxicity: Moderate; Genotoxic; Reproduction/development effects

GENERAL INFORMATION

Description

A fungicide used to control pathogens on a range of crops including potatoes and other crops.

Example pests controlled

Foliar late blight; Downy mildew; Powdery mildew

Example applications

Potatoes; Tomatoes; Grapes; Hops; Sugarbeet; Vines

Efficacy & activity

Efficacy has been demonstrated from pilot studies and extensive global use.

Availability status

Current

Introduction & key dates

1976, first reported; mid-1970s first marketed

GB regulatory status

GB COPR regulatory status

Approved

Date COPR inclusion expires

31/08/2029

GB LERAP status

Check label - may vary with formulation

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status

Approved

Dossier rapporteur/co-rapporteur

Lithuania/Finland

Date EC 1107/2009 inclusion expires

15/08/2026

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

USA; Iran; Morocco

Chemical structure

Isomerism

Exists as both E and Z isomers but the E-isomer is overwhelmingly favoured thermodynamically. Minimum E:Z ratio 99:1

Chemical formula

C₇H₁₀N₄O₃

Canonical SMILES

CCNC(=O)NC(=O)C(=NOC)C#N

Isomeric SMILES

CCNC(=O)NC(=O)/C(=N/OC)/C#N

International Chemical Identifier key (InChIKey)

XERJKGMBORTKEO-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C7H10N4O3/c1-3-9-7(13)10-6(12)5(4-8)11-14-2/h3H2,1-2H3,(H2,9,10,12,13)/b11-5+

2D structure diagram/image available?

Yes

Cambridge Crystallographic Data Centre diagrams

Common Name	Relationship	Link
cymoxanil	E-isomer

General status

Pesticide type

Fungicide

Substance groups

Cyanoacetamide oxime fungicide; Urea fungicide; Nitrile fungicide

Minimum active substance purity

970 g kg⁻¹

Known relevant impurities

EU dossier - None declared

Substance origin

Synthetic

Mode of action

Foliar with protective and curative activity. Disrupts RNA synthesis by inhibiting dihydrofolate reductase, preventing the formation of essential cell components and halting fungal growth.

CAS RN

57966-95-7

EC number

261-043-0

CIPAC number

419

US EPA chemical code

129106

PubChem CID

5364079

CLP index number

616-035-00-5

Molecular mass

198.18

PIN (Preferred Identification Name)

(2E)-2-cyano-N-(ethylcarbamoyl)-2-(methoxyimino)acetamide

IUPAC name

1-[(EZ)-2-cyano-2-methoxyiminoacetyl]-3-ethylurea

CAS name

2-cyano-N-((ethylamino)carbonyl)-2-(methoxyimino)acetamide

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)

Examples of recorded resistance

Physical state

White to pale pink crystals

Formulations

Property

Value

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

Belchim
DuPont
Headland
Nufarm
Syngenta

Example products using this active

Besiege
Curzate
Matilda WG
Option
Tanos
Wakil XL
Cymoxanil 45WG
Pilaraxanil
Pilarezox
Cymbal 45

Formulation and application details

Often supplied as wettable granules or powders that are mixed with water and applied as a spray or used as a seed treatment

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

780

Moderate

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

28000

Ethyl acetate

62400

Acetone

5290

Toluene

n-Hexane

Melting point (°C)

160

Boiling point (°C)

Decomposes before boiling

Degradation point (°C)

180

Flashpoint (°C)

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

4.68 X 10⁰⁰

Calculated

Log P

0.67

Low

Fat solubility of residues

Solubility

Insoluble

Data type

Regulatory data

Density (g ml⁻¹)

1.31

Dissociation constant pKa) at 25 °C

9.3

Weak acid

Vapour pressure at 20 °C (mPa)

0.15

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

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

3.30 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

244nm = 9333 & 9297

Surface tension (mN m⁻¹)

68.7

at 19°C

Degradation

Property

Value

Source; quality score; and other information

Interpretation

General biodegradability

Not readily biodegradable

Soil degradation (days) (aerobic)

DT₅₀ (typical)

1.7

Non-persistent

DT₅₀ (lab at 20 °C)

1.7

Non-persistent

DT₅₀ (field)

3.5

Non-persistent

DT₉₀ (lab at 20 °C)

10.99

Non-persistent

DT₉₀ (field)

DT₅₀ modelling endpoint

Note

EU dossier 2020 Lab studies DT₅₀ range 0.09-7.29 days, DT₉₀ range 0.48-66.2 days, Soils=14

Dissipation rate RL₅₀ (days) on plant matrix

Value

Note

Dissipation rate RL₅₀ (days) on and in plant matrix

Value

3.0

Note

Published literature RL₅₀ range 1.2-5.3 days, 3 field crops, various matrices, n=3

Aqueous photolysis DT₅₀ (days) at pH 7

Value

1.7

Moderately fast

Note

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

Value

1.1

Non-persistent

Note

Stable at pH 4 and pH 5 at 20°C, DT₅₀ 0.02 days at pH 9 and 25 °C

Water-sediment DT₅₀ (days)

0.3

Fast

Water phase only DT₅₀ (days)

0.3

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)

0.302

Mobile

K_foc (mL g⁻¹)

19.6

¹/_n

0.87

Notes and range

EU 2020 RAR dossier kf range 0.014-0.91, K_foc range 2.7-87.1 mL g⁻¹, ¹/_n range 0.77--0.96, Soils=19

pH sensitivity

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

1.47

Calculated

Low leachability

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

Value

3.24 X 10^-03

Calculated

Note

Potential for particle bound transport index

Low

Calculated

Potential for loss via drain flow

Mobile

Calculated

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

1.776

Calculated using the Atkinson method. Assumed 1.5E+06 OH/cm³, 12 hr

Below the level of concern for long-range air transport

Bio-concentration factor

BCF (l kg⁻¹)

Low risk

Based on LogP < 3

Low risk

CT₅₀ (days)

No data

Known soil metabolites

Metabolite

Major/Minor fraction

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

Estimated maximum occurrence fraction

Notes

1-ethyl-5-(methoxyimino)2,4-imidazolidin-2,4-dione (Ref: IN-R3273)

Minor fraction

0.024

3-ethyl-4-(methoxyamino)-2,5-dioxoimidazolidine-4-carbonitrile (Ref: IN JX915)

Minor fraction

0.033

ethylimidazolidinetrione-5-(o-methyloxime)

Minor fraction

Oxamic acid (Ref: IN-18474)

Minor fraction

0.076

1-ethyl 5,6-di-2,4(1H,3H)pyridenedione (Ref: IN U3204)

Major fraction

0.700

2-cyano-2-methoxyiminoacetic acid (Ref: IN W3595)

Major fraction

0.181

3-ethyl-4-(methoxyamino)-2,5-dioxoimidazolidine-4-carboxamide (Ref: IN KQ960)

Minor fraction

0.099

Oxalic acid (Ref: AS992)

Minor fraction

N-ethylurea

Minor fraction

Glycine

Minor fraction

1-ethylimidazolidine-2,4,5-trione (Ref: IN-T4226)

Minor fraction

0.038

Known groundwater metabolites

None

Other known metabolites

Metabolite name and reference

Aliases

Formation medium / Rate

Estimated maximum occurrence fraction

cyano(methoxyimino)acetic acid (Ref: IN-U3595)

Rat; Plant; Surface water

{[(ethylamino)carbonyl]}ethylamino)carbonyl]amino}oxoacetic acid (Ref: IN-KP533)

Rat; Plant; Surface water; Sediment

1-ethyl-5-(methoxyimino)2,4-imidazolidin-2,4-dione (Ref: IN-R3273)

Plant; Surface water

3-ethyl-4-(methoxyamino)-2,5-dioxoimidazolidine-4-carbonitrile (Ref: IN JX915)

Plant; Surface water; Sediment

3-ethyl-4-(methoxyamino)-2,5-dioxoimidazolidine-4-carboxamide (Ref: IN KQ960)

Plant; Surface water

(2E)-cyano(hydroxyimino)acetic acid (Ref: IN-R3274)

Surface water

1-ethylimidazolidine-2,4,5-trione (Ref: IN-T4226)

Rat; Plant; Surface water

1-ethyl 5,6-di-2,4(1H,3H)pyridenedione (Ref: IN U3204)

Rat; Plant; Surface water

ECOTOXICOLOGY

Terrestrial ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

356

Rat

Moderate

Mammals - Short term dietary NOEL

(mg kg⁻¹)

47.6

Rat

High

(ppm diet)

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

31.6

Rat Reproductive NOAEL

Moderate

Birds - Acute LD₅₀ (mg kg⁻¹)

> 486

Anas platyrhynchos

Moderate

Birds - Short term dietary (LC₅₀/LD₅₀)

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

14.9

Anas platyrhynchos NOEL

Moderate

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

> 1000

Eisenia foetida

Low

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

6.6

Eisenia foetida

Moderate

Soil micro-organisms

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

Dose: 1.44 kg 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)

> 100

Apis mellifera

Low

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

> 85.3

Apis mellifera

Moderate

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

Chronic as 10-day LDD₅₀ µg bee⁻¹ day⁻¹

4.88

Apis mellifera

Notes

[The residual time to 25% mortality (RT25) value for honeybees is 1 hrs - USEPA data]

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) as Mortality ER₅₀ g ha⁻¹

> 480

Chrysoperla carnea

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

> 480

Aphidius rhopalosiphi Adult

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

> 480

Typhlodromus pyri

Beneficial insects (Ground beetles) as Mortality ER₅₀ g ha⁻¹

> 480

Poecilus cupreus

Aquatic ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

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

Lepomis macrochirus

Moderate

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

0.22

Oncorhynchus mykiss LOEC

Moderate

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

8.40

Danio rerio EC₅₀ Embryo

Moderate

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

Daphnia magna

Moderate

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

0.067

Daphnia magna

Moderate

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

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

44.4

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)

> 0.7

Lemna gibba

Moderate

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

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

0.254

Anabaena flos-aquae

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)

356

Rat

Moderate

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

2000

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

> 5.06

Rat 4 hr (nose only)

Other Mammal toxicity endpoints

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

0.013

Dog SF=100

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

0.08

Rabbit 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)

0.01

Dog SF=100

Dermal penetration studies (%)

1.0-75.0

concentration dependent

Dangerous Substances Directive 76/464

Exposure Routes

Public

Acceptable risk to bystanders for intended uses

Occupational

Acceptable risk to operators wearing protective clothing

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

Mammalian dose elimination route and rate

Rapid and extensive elimination mainky via the urine

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

Eye irritant

Phototoxicant

General human health issues

Possible testes and liver toxicant

Handling issues

Property

Value and interpretation

General

Not explosive or oxidising
IMDG Transport Hazard Class 9
Not expected to auto-ignite; Not highly flammable

CLP classification 2013

Health: H302, H317, H361fd, H373
Environment: H400, H410

WHO Classification

II (Moderately hazardous)

UN Number

UN3077

Waste disposal & packaging

Packaging Group III (minor danger)

Shelf-life, storage, stability and reactivity

Stable at normal temperatures and storage conditions.

TRANSLATIONS

Language

Name

English

cymoxanil

French

cymoxanil

German

Cymoxanil

Danish

cymoxanil

Italian

cimoxanil

Spanish

cimoxanilo

Greek

Polish

cymoksanil

Swedish

cymoxanil

Hungarian

cymoxanil

Dutch

cymoxanil

Norwegian

cymoksanil

Record last updated:	26/05/2025
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