Oxamyl (Ref: DPX D1410)

Oxamyl (Ref: DPX D1410)	Last updated: 24/02/2021
(Also known as: thioxamyl; oxamil; vydate; dioxamyl)

SUMMARY

Oxamyl is a carbamate pesticide currently approved for use in the EU. It is highly soluble in water, has a low volatility and may have the capacity to leach to groundwater. It is not expected to be persistent in soil or water systems. It is highly toxic to mammals, is a cholinesterase inhibitor and a neurotoxicant. Oxamyl is not expectd to accumulate in soils. It demonstrates a moderate to high level of toxicity to most biodiversity.

GENERAL INFORMATION

Description

A soil-applied nematicide and insecticide used to control chewing and sucking insects on field and other crops

Example pests controlled

Aphids; Spider mites; Ticks; Roundworms; Nematodes including Globodera and Heterodera sp., Trichodorus and Paratrichodorus sp., Radopholus similis, Ditylenchus sp.

Example applications

Field crops; Vegetables including carrots, cucubits and celery; Tobacco; Potatoes; Fruit including apples, bananas, citrus, tomatoes; Cotton; Ornamentals;

Efficacy & activity

Shown to be effective in field trials

Availability status

Current

Introduction & key dates

1974, first sold

UK regulatory status

UK COPR regulatory status

Approved

Date COPR inclusion expires

31/01/2024

UK LERAP status

None

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status

Approved

Dossier rapporteur/co-rapporteur

Italy/France

Date EC 1107/2009 inclusion expires

31/01/2021

EU Candidate for substitution (CfS)

Yes - low ADI / ARfD / AOEL

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

Australia

Chemical structure

Isomerism

Isomeric

Chemical formula

C₇H₁₃N₃O₃S

Canonical SMILES

CNC(=O)ON=C(C(=O)N(C)C)SC

Isomeric SMILES

CNC(=O)O/N=C(/C(=O)N(C)C)\SC

International Chemical Identifier key (InChIKey)

KZAUOCCYDRDERY-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C7H13N3O3S/c1-8-7(12)13-9-5(14-4)6(11)10(2)3/h1-4H3,(H,8,12)

2D structure diagram/image available?

Yes

General status

Pesticide type

Insecticide, Acaricide, Nematicide

Substance group

Carbamate

Minimum active substance purity

936.1 g kg⁻¹

Known relevant impurities

EU dossier - None declared

Substance origin

Synthetic

Mode of action

Systemic with contact action. Acetylcholinesterase (AChE) inhibitor.

CAS RN

23135-22-0

EC number

245-445-3

CIPAC number

342

US EPA chemical code

103801

PubChem CID

9595287

Molecular mass

219.26

PIN (Preferred Identification Name)

IUPAC name

(EZ)-N,N-dimethyl-2-methylcarbamoyloxyimino-2-(methylthio)acetamide

CAS name

methyl 2-(dimethylamino)-N-(((methylamino)carbonyl)oxy)-2-oxoethanimidothioate

Other status information

Marine Pollutant; Possible drinking water contaminant

Relevant Environmental Water Quality Standards

Herbicide Resistance Classification (HRAC)

Not applicable

Herbicide Resistance Classification (WSSA)

Not applicable

Insecticide Resistance Classification (IRAC)

Fungicide Resistance Classification (FRAC)

Not applicable

Examples of recorded resistance

Anthonomus grandis, Diglyphus begini, Ganaspidium utilis, Leptinotarsa decemlineata, Lygus lineolaris, Phyllonorycter blancardella

Physical state

Colourless or white crystalline powder

Related substances & organisms

cyclohexanone

Formulations

Property

Value

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

Vydate 10G
Tevday

Example products using this active

DuPont
Agchem Access

Formulation and application details

Often supplied as granules or water-soluble liquid that is applied directly to the soil before drilling or planting

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

148100

High

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

10500

n-Heptane

250000

Methanol

250000

Acetone

41300

Xylene

Melting point (°C)

98.5

Boiling point (°C)

Decomposes before boiling

Degradation point (°C)

165

Flashpoint (°C)

57.4

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

3.63 X 10^-01

Calculated

Log P

-0.44

Low

Bulk density (g ml⁻¹)

1.31

Dissociation constant pKa) at 25 °C

-2.11

Estimated, Very strong acid

Vapour pressure at 20 °C (mPa)

0.018

Low volatility

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

2.7 X 10^-08

Non-volatile

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

Neutral solution: 290nm = 80.1
Acidic solution: 290nm = 60.1
Basic solution: 290nm = 1154

Surface tension (mN m⁻¹)

73.1

at 20°C

Degradation

Property

Value

Source; quality score; and other information

Interpretation

General biodegradability

Not readily biodegradable

Soil degradation (days) (aerobic)

DT₅₀ (typical)

5.3

Non-persistent

DT₅₀ (lab at 20 °C)

5.3

Non-persistent

DT₅₀ (field)

6.0

Non-persistent

DT₉₀ (lab at 20 °C)

Non-persistent

DT₉₀ (field)

DT₅₀ modelling endpoint

Note

EU 2020 dossier lab studies DT₅₀ (normalised) range 0.6-19.4 days, DT₉₀ (not normalised) range 9.9-38.2 days, Soils = 9; field studies DT₅₀ (normalised) range 5.0-6.9, Soils =2

Dissipation rate RL₅₀ on plant matrix

Value

2.7

Note

Cotton, n=1

Dissipation rate RL₅₀ on and in plant matrix

Value

8.9

Note

Published literature RL₅₀ range 2.9-15.0 days, 2 crops undercover/lab, various matrices, n=2

Aqueous photolysis DT₅₀ (days) at pH 7

Value

3.5

Moderately fast

Note

at pH 5, 20 °C

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

Value

21.1

Non-persistent

Note

pH sensitive: Stable at pH 4; DT₅₀ = 0.2 days at pH 9

Water-sediment DT₅₀ (days)

0.7

Fast

Water phase only DT₅₀ (days)

Soil adsorption and mobility

Property

Value

Source; quality score; and other information

Interpretation

Linear

K_d

0.24

Very mobile

K_oc

14.91

Notes and range

EU 2017 dossier K_d range 0.6-19.4 mL g⁻¹, K_oc range 4.3-39.0 mL g⁻¹, Soils=11

Freundlich

K_f

0.22

Very mobile

K_foc

13.59

¹/_n

0.92

Notes and range

EU 2017 dossier kf range 0.05-0.598 mL g⁻¹, K_foc range 4.1-37.0 mL g⁻¹, ¹/_n range 0.66-1.08, Soils=11

pH sensitivity

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

2.23

Calculated

Transition state

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

Value

5.12 X 10^-03

Calculated

Note

Potential for particle bound transport index

Low

Calculated

Potential for loss via drain flow

Very mobile

Calculated

Key metabolites

Metabolite

Formation medium

Estimated maximum occurrence fraction

1107/2009 relevancy

methyl 2-(dimethylamino)-N-(((methylamino)carbonyl)oxy)-2-oxoethanimidothioate (Ref: IN-A2213)

Soil

0.510

Major fraction, Relevant

N,N’-dimethyloxamic acid (Ref: IN-D2708)

Soil

0.780

Major fraction, Relevant

Other known metabolites

Metabolite name and reference

Aliases

Formation medium / Rate

Estimated maximum occurrence fraction

Metabolising enzymes

methyl 2-(dimethylamino)-N-hydroxy-2-oxoethanimidothioate

Soil (Anaerobic)

Ref: IN-L2953

Rat

N,N-dimethyl-1-cyanoformamid (Ref: IN-D0079)

DMCF

Soil; Water/sediment

N,N-dimethylethanediamide (Ref: IN-T2921)

DMEA; DOA

Water/sediment

ECOTOXICOLOGY

Property

Value

Source; quality score; and other information

Interpretation

Bio-concentration factor

BCF (l kg⁻¹)

Low potential

CT₅₀ (days)

Not available

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

2.5

Rat

High

Mammals - Short term dietary NOEL

(mg kg⁻¹)

0.93

Dog 1 year

High

(ppm diet)

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

12.2

Rat Reproductive NOAEL

Moderate

Birds - Acute LD₅₀ (mg kg⁻¹)

3.16

Anas platyrhynchos

High

Birds - Short term dietary (LC₅₀/LD₅₀)

340 mg kg feed⁻¹

Anas platyrhynchos

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

1.5

Anas platyrhynchos

High

Fish - Acute 96 hour LC₅₀ (mg l⁻¹)

3.13

Oncorhynchus mykiss

Moderate

Fish - Chronic 21 day NOEC (mg l⁻¹)

0.5

Pimephales promelas 28 day

Moderate

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

0.319

Daphnia magna

Moderate

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

0.027

Daphnia magna

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 - Acute 7 day EC₅₀, biomass (mg l⁻¹)

3.57

Lemna gibba

Moderate

Non-target plants

> 2.24

Zea mays Avena sativa Allium cepa Lolium perenne Cucumis sativus Brassica napus
ER₅₀, vegetative vigour
as kg ha⁻¹

> 2.24

Zea mays Avena sativa Allium cepa Lolium perenne Cucumis sativus Brassica napus
ER₅₀, Seedling emergence
as kg ha⁻¹

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

0.93

Pseudokirchneriella subcapitata

Moderate

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

0.5

Unknown species

Moderate

Honeybees (Apis spp.)

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

0.47

Apis meliifera

High

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

0.38

Apis meliifera

High

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)

39.3

Bombus terrestris

Moderate

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

0.36

Bombus terrestris

High

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)

112

Eisenia foetida

Moderate

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

6.4

Eisenia foetida 56 day

Moderate

Other soil macro-organisms

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

0.25

Folsomia foetida

Other arthropod (1)

LR₅₀ g ha⁻¹

0.03

48 hour
Aphidius rhopalosiphi

% Effect

Other arthropod (2)

LR₅₀ g ha⁻¹

1.8

7 day
Typhlodromus pyri

% Effect

Soil micro-organisms

Nitrogen mineralisation: No significant adverse effect [Dose: 5 mg kg⁻¹ soil]
Carbon mineralisation: No significant adverse effect [Dose: 10 mg kg⁻¹ soil]

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)

2.5

Rat

High

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

5000

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

0.056

Rat (nose only)

Other Mammal toxicity endpoints

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

0.001

Rat SF=100

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

0.001

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)

0.01

Rat SF=100

Dermal penetration studies (%)

Dangerous Substances Directive 76/464

Exposure Routes

Public

No unacceptable risks to bystanders identified

Occupational

Negligible risk to operators

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

; ; ; ;

Reproduction / development effects

Acetyl cholinesterase inhibitor

Neurotoxicant

Respiratory tract irritant

Skin irritant

Skin sensitiser

No data found

Eye irritant

Phototoxicant

General human health issues

Harmful if ingested
Endocrine issues - weak estrogen effect

Handling issues

Property

Value and interpretation

General

Corrosive
Not explosive or oxidising
IMDG Transport Code is usually 6.1

CLP classification 2013

Health: H300, H312, H330
Environment: H411

EC Risk Classification

T+ - Very toxic: R26/28
Xn - Harmful: E21
N - Dangerous for the environment: R51, R53

EC Safety Classification

S1/2, S36/37, S45, S61

WHO Classification

Ib (Highly hazardous / Highly hazardous)

UN Number

Usually 2757

Waste disposal & packaging

Packaging Group II (medium danger)

TRANSLATIONS

Language

Name

English

oxamyl

French

oxamyl

German

Oxamyl

Danish

oxamyl

Italian

oxamil

Spanish

oxamilo

Greek

Polish

oksamyl

Swedish

Hungarian

oxamil

Dutch

oxamyl

Record last updated:	24/02/2021
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