Dichlorvos (Ref: OMS 14)

Dichlorvos (Ref: OMS 14)	Last updated: 24/08/2024
(Also known as: DDVP; dichlorfos; DDVF; denkavepon; vapona)

SUMMARY

Dichlorvos is an organophosphate fumigant insecticide. It has a high aqueous solubility, quite volatile and, based on its chemical properties, is unlikely to leach to groundwater. It is not usually persistent in soils or water. It is highly toxic to mammals and has a high tendency to bioaccumulate. Dichlorvos is also a probable mutagen, a neurotoxin and may damage reproduction and/or development. It is considered to be an acetyl cholinesterase inhibitor. It has a moderate to high toxicity to most biodiversity including honeybees.

GENERAL INFORMATION

Description

A contact and fumigant insecticide used in a range of crop and non-crop situations. Can also be a pesticide transformation product

Availability status

Current

Introduction & key dates

1959, introduced

Examples of veterinary uses

Examples of species treated

Approval status

VMR 2013/2033 approval status (GB/UK)

EU Regulatory approval status

Chemical structure

Isomerism

None

Chemical formula

C₄H₇C₁₂O₄P

Canonical SMILES

COP(=O)(OC)OC=C(Cl)Cl

Isomeric SMILES

O=P(O\C=C(/Cl)Cl)(OC)OC

International Chemical Identifier key (InChIKey)

OEBRKCOSUFCWJD-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C4H7Cl2O4P/c1-8-11(7,9-2)10-3-4(5)6/h3H,1-2H3

2D structure diagram/image available?

Yes

General status

Veterinary substance type

Metabolite Type

Soil

Substance groups

Organophosphate insectcide; Organophosphate acaricide

Minimum active substance purity

950 g kg⁻¹

Known relevant impurities

EU dossier - Chloral (trichloroacetaldehyde) 5 g kg⁻¹

Substance origin

Synthetic

Mode of action

Respiratory, contact and stomach action. Acetylcholinesterase (AchE) inhibitor.

Molecular targets

[Cholinesterase, Inhibitor]

CAS RN

62-73-7

EC number

200-547-7

CIPAC number

US EPA chemical code

084001

PubChem CID

3039

CLP index number

015-019-00-X

Therapeutic Class

ATCvet Code

Controlled Drug?

Regulation 37/2010 MRL Classification

Molecular mass

220.98

PIN (Preferred Identification Name)

2,2-dichloroethenyl dimethyl phosphate

IUPAC name

2,2-dichlorovinyl dimethyl phosphate

CAS name

2,2-dichloroethenyl dimethyl phosphate

Other status information

Severe Marine Pollutant; Evidence of use in third world countries; Chemical subject to PIC regulations; Subject to the provisions of the UK Poisons Act 1972

Relevant Environmental Water Quality Standards

UK Statutory standard for the protection of aquatic life in inland waters: 0.001 µg l⁻¹ as annual average
UK Statutory standard for the protection of aquatic life in coastal and territorial waters: 0.04 µg l⁻¹ as annual average

Physical state

Pale yellow clear liquid

Can be a metabolite of:

Parent

Formation medium

Estimated maximum occurrence fraction

1107/2009 relevancy

trichlorfon

Groundwater

Relevant

trichlorfon

Soil

0.245

Major fraction

naled

Soil

0.165

Major fraction

Formulations

Property

Product

Manufacturer

Authorisation Route

Legal Class (GB/UK)

Example products (past and present) using this active

Formulation and application details

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

18000

High

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

Miscible

Ethanol

Miscible

Acetone

Miscible

Toluene

Miscible

n-Hexane

Melting point (°C)

Boiling point (°C)

Decomposes before boiling

Degradation point (°C)

190

Flashpoint (°C)

350

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

7.94 X 10⁰¹

Calculated

Log P

1.9

Low

Fat solubility of residues

Solubility

Data type

Density (g ml⁻¹)

1.42

Dissociation constant pKa) at 25 °C

Not applicable

No dissociation

Vapour pressure at 20 °C (mPa)

2100

Highly volatile. If applied directly to plants or soil, drift is a concern & mitigation is advisable

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

2.58 X 10^-02

Non-volatile

Volatilisation as max % of applied dose lost

From plant surface

From soil surface

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

Maxima at 204nm

Surface tension (mN m⁻¹)

Refractive Index

Environmental release

Degradation

Property

Value

Source; quality score; and other information

Interpretation

Soil degradation (days) (aerobic)

DT₅₀ (typical)

Non-persistent

DT₅₀ (lab at 20 °C)

Non-persistent

DT₅₀ (field)

DT₉₀ (lab at 20 °C)

DT₉₀ (field)

Note

Other sources: DT₅₀ 0.5 days (DW4), <1 day (R3)

Manure DT₅₀ (days)

Aqueous photolysis DT₅₀ (days) at pH 7

Value

Note

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

Value

4.7

Non-persistent

Note

Water-sediment DT₅₀ (days)

0.22

Fast

Water 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

[Wheat grain: 2 wks @ 30 DegC, 50% RH; Modelled data], [Dates (Khalal): 5.3 days @ 3 DegC; Lab study], [Dates (Khalal): 8.5 days @ 22 DegC; Lab study], [Dates (Khalal): 18 days @ 43 DegC; Lab study], [Corn grain: 1.8 days @ 20-25 DegC, 40-60% RH; Lab study]

Soil adsorption and mobility

Property

Value

Source; quality score; and other information

Interpretation

Linear

K_d (mL g⁻¹)

Mobile

K_oc (mL g⁻¹)

Notes and range

Freundlich

K_f (mL g⁻¹)

K_foc (mL g⁻¹)

¹/_n

Notes and range

pH sensitivity

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

0.69

Calculated

Low leachability

Bio-concentration factor

BCF (l kg⁻¹)

Low risk

Based on LogP < 3

Low risk

CT₅₀ (days)

Known soil and groundwater metabolites

None

Other known metabolites

Metabolite name and reference

Aliases

Formation medium / Rate

Estimated maximum occurrence fraction

mercapturic acid

Rat (Urine)

methyl cystein

Rat (Urine)

urea

Rat (Urine)

diemethyl dichlorvos
Note: Toxicologically relevant

Rat

2,2-dichloroacetaldehyde
Note: Toxicologically relevant

Rat

2,2-dichloroacetic acid
Note: Toxicologically relevant

Rat

dimethylphosphate

Rat (Urine)

dichloroethanol glucuronide

Rat (Urine)

hippuric acid

Rat (Urine)

ECOTOXICOLOGY

Terrestrial ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

Rat

High

Mammals - Short term dietary NOEL

(mg kg⁻¹)

0.5

Rat

High

(ppm diet)

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

Birds - Acute LD₅₀ (mg kg⁻¹)

Colinus virginianus

High

Birds - Short term dietary (LC₅₀/LD₅₀)

251 ppm

Colinus virginianus

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

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

Eisenia foetida

Moderate

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

Soil micro-organisms

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

Dose: 13.4 mg kg⁻¹ soil

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)

0.46

Apis mellifera

High

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

0.29

Apis mellifera

High

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

Chronic

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)

Aquatic ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

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

0.55

Oncorhynchus mykiss

Moderate

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

0.11

Pimephales promelas 28 day

Moderate

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

> 8.1

Danio rerio Embryo

Moderate

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

0.00019

Daphnia magna

High

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

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

> 0.0001

Ceriodaphnia dubia

High

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

0.019

Americamysis bahia

High

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)

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

52.8

Scenedesmus subspicatus

Low

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

4.73

Unknown species

Low

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)

Rat

High

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

120

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

0.083

Rat

Other Mammal toxicity endpoints

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

0.00008

Dog SF=100

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

0.002

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)

0.0005

Dog SF=100

Dermal penetration studies (%)

Dangerous Substances Directive 76/464

List I; List II

Exposure Routes

Public

Low risk to Europeans as no longer approved for use

Occupational

Primary risk if re-entry occurs post application

Mammalian dose elimination route and rate

Rapidly metabolised and excreted in the urine

Health issues

Specific human health issues

Carcinogen

Genotoxic

Endocrine disruptor

; ; ; ;

Reproduction / development effects

Acetyl cholinesterase inhibitor

Neurotoxicant

No data found

Respiratory tract irritant

Skin irritant

Skin sensitiser

Eye irritant

Phototoxicant

No data found

General human health issues

IARC Group 2B carcinogen; US EPA - some weak evidence to suggest carcinogenicity
Highly toxic, may be fatal if inhaled, swallowed or absorbed through skin
Some minor concerns regarding endocrine disruption
Endocrine issues - Weak androgen-receptor antagonist

Handling issues

Property

Value and interpretation

General

Corrosive in molten state
IMDG Transport Hazard Class 6.1

CLP classification 2013

Health: H301, H311, H317, H330
Environment: H400

WHO Classification

Ib (Highly hazardous)

UN Number

UN2810

Waste disposal & packaging

Packaging Group II (moderate danger)

Shelf-life, storage, stability and reactivity

Chemically stable under standard ambient conditions

TRANSLATIONS

Language

Name

English

dichlorvos

French

dichlorvos

German

Dichlorvos

Danish

dichlorvos

Italian

diclorvos

Spanish

diclorvos

Greek

dichlorvos

Polish

dichlorfos

Swedish

Hungarian

dichlorvos

Dutch

dichloorvos

Norwegian

Record last updated:	24/08/2024
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