Chlormephos (Ref: MC 2188)

Chlormephos (Ref: MC 2188)	Last updated: 14/01/2023
(Also known as: chlormethylfos; chlormefos)

SUMMARY

Chlormephos is an organophosphorus insecticide. It has a moderate aqueous solubility and is not volatile. based on its chemical properties it would not normally be expected to leach to groundwater. It is not normally persistent in soil systems. It is highly toxic to mammals if ingested, inhaled or absorbed through skin , a cholinesterase inhibitor and a neurotoxciant. Ecotoxicology data is sparse but chlormephos is highly toxic to honey bees and moderately toxic to birds, fish and earthworms.

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: Slightly mobile; Potential for particle bound transport: Medium Warning: Significant data are missing	Ecotoxicity High alert: Bees acute unknown ecotoxicity: High Warning: Significant data are missing	Human health High alert: Mammals acute toxicity: High; Acetyl cholinesterase inhibitor; Neurotoxicant Warning: Significant data are missing

GENERAL INFORMATION

Description

An insecticide used to control a wide range of foliage and soil dwelling pests

Example pests controlled

Wireworms; Millipedes; Symphylids; Mealybugs; Cutowrms; Whiteflies, Leaf rollers; Caperpillars; Scale insects; Grasshoppers; Apple moth; Earwigs; Beetles; Borers

Example applications

Maize; Sugarbeet; Fruit including apples, pears, avocado, grapes, mango, citrus. kiwi; Vegetables; Cereals; Pasture

Efficacy & activity

Availability status

Introduction & key dates

circa 1973

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

Chemical structure

Isomerism

None

Chemical formula

C₅H₁₂ClO₂PS₂

Canonical SMILES

CCOP(=S)(OCC)SCCl

Isomeric SMILES

No data

International Chemical Identifier key (InChIKey)

QGTYWWGEWOBMAK-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C5H12ClO2PS2/c1-3-7-9(10,8-4-2)11-5-6/h3-5H2,1-2H3

2D structure diagram/image available?

Yes

General status

Pesticide type

Insecticide

Substance groups

Organophosphate insecticide; Organothiophosphate insecticide

Minimum active substance purity

Known relevant impurities

Substance origin

Synthetic

Mode of action

Non-systemic with contact and stomach action. Acetylcholine esterase inhibitor.

CAS RN

24934-91-6

EC number

246-538-1

CIPAC number

337

US EPA chemical code

295300

PubChem CID

32739

CLP index number

015-114-00-6

Molecular mass

234.70

PIN (Preferred Identification Name)

S-(chloromethyl) O,O-diethyl phosphorodithioate

IUPAC name

S-chloromethyl O,O-diethyl phosphorodithioate

CAS name

S-(chloromethyl) O,O-diethyl phosphorodithioate

Other status information

Marine Pollutant; Chemical subject to PIC regulations

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

None identified

Physical state

Colourless liquid

Formulations

Property

Value

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

Bayer CropScience
Rhone Poulenc
Murphy

Example products using this active

Dotan

Formulation and application details

Usually supplied in a granular formulations

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

Moderate

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

Miscible

Acetone

Miscible

Methanol

Miscible

Ethanole

Miscible

Xylene

Melting point (°C)

Boiling point (°C)

Degradation point (°C)

Flashpoint (°C)

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

1.10 X 10⁰³

Calculated

Log P

3.04

High

Fat solubility of residues

Solubility

Data type

Density (g ml⁻¹)

1.26

Dissociation constant pKa) at 25 °C

Vapour pressure at 20 °C (mPa)

0.0076

Low volatility

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

2.97 X 10⁰¹

Moderately 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)

Non-persistent

DT₅₀ (lab at 20 °C)

DT₅₀ (field)

DT₉₀ (lab at 20 °C)

DT₉₀ (field)

DT₅₀ modelling endpoint

Note

Other sources: DT₅₀ 28 days, sandy soil (R4)

Dissipation rate RL₅₀ on plant matrix

Value

Note

Dissipation rate RL₅₀ on and in plant matrix

Value

Note

Aqueous photolysis DT₅₀ (days) at pH 7

Value

Note

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

Value

Note

Water-sediment DT₅₀ (days)

Water phase only DT₅₀ (days)

Soil adsorption and mobility

Property

Value

Source; quality score; and other information

Interpretation

Linear

K_d

Slightly mobile

K_oc

1100

Notes and range

Estimated

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

1.25

Calculated

Low leachability

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

Value

2.49 X 10^-02

Calculated

Note

Potential for particle bound transport index

Medium

Calculated

Potential for loss via drain flow

Slightly mobile

Calculated

Bio-concentration factor

BCF (l kg⁻¹)

120

Whole fish

Threshold for concern

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

ethion (Ref: ENT 24105)

Known groundwater metabolites

None

Other known metabolites

None

ECOTOXICOLOGY

Terrestrial ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

> 7

Rat

High

Mammals - Short term dietary NOEL

(mg kg⁻¹)

Rat

(ppm diet)

> 0.39

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

Birds - Acute LD₅₀ (mg kg⁻¹)

260

Coturnix japonica

Moderate

Birds - Short term dietary (LC₅₀/LD₅₀)

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

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

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

> 1.0

Eisenia andrei as LOEC

Moderate

Soil micro-organisms

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)

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)

> 0.9

High

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 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

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

Fish - Acute 96 hour LC₅₀ (mg l⁻¹)

2.5

Rasbora heteromorpha

Moderate

Fish - Chronic 21 day NOEC (mg l⁻¹)

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

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

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)

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

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

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)

> 7

Rat

High

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

7.0

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

Other Mammal toxicity endpoints

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

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

List I; List II

Exposure Routes

Public

Occupational

May be absorbed through dermal contact

MRLs

European

EU MRL pesticide database

Great Britain

GB MRL Register

Notes

Drinking Water Standards

Drinking Water MAC (μg l⁻¹)

Mammalian dose elimination route and rate

Eliminated within 24hrs via urine

Health issues

Specific human health issues

Carcinogen

Genotoxic

Endocrine disruptor

No data found

; ; ; ;

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

Very toxic if ingested, inhaled or absorbed through skin

Handling issues

Property

Value and interpretation

General

No information available

CLP classification 2013

Health: H300, H310
Environment: H400, H410

WHO Classification

Ia (Extremely hazardous)

UN Number

3018

Waste disposal & packaging

TRANSLATIONS

Language

Name

English

chlormephos

French

chlorméphos

German

Chlormephos

Danish

chlormephos

Italian

clormefos

Spanish

clormefos

Greek

chlormephos

Polish

chloromefos

Swedish

Hungarian

Dutch

chloormefos

Record last updated:	14/01/2023
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