Coumachlor

Coumachlor	Last updated: 14/01/2023
(Not known by any other names)

SUMMARY

Coumachlor is a first generation rodenticide which is now largely obsolete. There are many gaps in the available data, however, It has a low aqueous solubility and is not volatile. It is highly toxic to birds and aquatic invertebrates. It also has a high oral toxicity to mammals.

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 Low alert: Drainflow: Non-mobile Warning: Significant data are missing	Ecotoxicity High alert: Birds acute ecotoxicity: High; Daphnia acute ecotoxicity: High	Human health High alert: Mammals acute toxicity: High Warning: Significant data are missing

GENERAL INFORMATION

Description

An obsolete coumarin rodenticide

Example pests controlled

Rats; Mice; Other small rodents

Example applications

Rats; Mice; Other small rodents

Efficacy & activity

Availability status

Considered obsolete but may be available in some countries

Introduction & key dates

circa 1952

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

Poland

Date EC 1107/2009 inclusion expires

Expired

EU Candidate for substitution (CfS)

Not applicable

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

A chiral molecule. Coumachlor is racemic.

Chemical formula

C₁₉H₁₅ClO₄

Canonical SMILES

CC(=O)CC(C1=CC=C(C=C1)Cl)C2=C(C3=CC=CC=C3OC2=O)O

Isomeric SMILES

International Chemical Identifier key (InChIKey)

DEKWZWCFHUABHE-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C19H15ClO4/c1-11(21)10-15(12-6-8-13(20)9-7-12)17-18(22)14-4-2-3-5-16(14)24-19(17)23/h2-9,15,22H,10H2,1H3

2D structure diagram/image available?

Yes

Cambridge Crystallographic Data Centre diagrams

Common Name	Relationship	Link
coumachlor	Unstated isomer

General status

Pesticide type

Rodenticide

Substance groups

Coumarin rodenticide

Minimum active substance purity

Known relevant impurities

Substance origin

Synthetic

Mode of action

1st generation anticoagulant, blocks formation of prothrombin, inhibits blood coagulation causing death by internal haemorrhage

CAS RN

81-82-3

EC number

201-378-1

CIPAC number

188

US EPA chemical code

224200

PubChem CID

54682651

CLP index number

607-057-00-6

Molecular mass

342.77

PIN (Preferred Identification Name)

rac-3-[(1R)-1-(4-chlorophenyl)-3-oxobutyl]-4-hydroxy-2H-1-benzopyran-2-one

IUPAC name

3-[(1RS)-1-(4-chlorophenyl)-3-oxobutyl]-4-hydroxycoumarin

CAS name

3-[1-(4-chlorophenyl)-3-oxobutyl]-4-hydroxy-2H-1-benzopyran-2-one

Other status information

Relevant Environmental Water Quality Standards

Herbicide Resistance Classification (HRAC)

Not applicable

Herbicide Resistance Classification (WSSA)

Not applicable

Insecticide Resistance Classification (IRAC)

Not applicable

Fungicide Resistance Classification (FRAC)

Not applicable

Examples of recorded resistance

Physical state

Off-white crystalline powder

Formulations

Property

Value

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

Ciba-geigy

Example products using this active

Tomorin
Ratilan

Formulation and application details

Usually supplied as bait or tracking powders

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

1.5

Low

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

Melting point (°C)

170

Boiling point (°C)

Degradation point (°C)

Flashpoint (°C)

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

1.35 X 10⁰⁴

Calculated

Log P

4.13

High

Fat solubility of residues

Solubility

Data type

Density (g ml⁻¹)

1.38

Dissociation constant pKa) at 25 °C

Vapour pressure at 20 °C (mPa)

0.013

Low volatility

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

1.71 X 10^-08

Non-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)

DT₅₀ (lab at 20 °C)

DT₅₀ (field)

DT₉₀ (lab at 20 °C)

DT₉₀ (field)

DT₅₀ modelling endpoint

Note

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

Non-mobile

K_oc

13440

Notes and range

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

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

Value

Cannot be calculated

Note

Potential for particle bound transport index

Potential for loss via drain flow

Bio-concentration factor

BCF (l kg⁻¹)

CT₅₀ (days)

Known metabolites

None

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)

(ppm diet)

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

Birds - Acute LD₅₀ (mg kg⁻¹)

>> 4.3

Colinus virginianus

High

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)

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)

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)

> 340

Lepomis macrochirus

Low

Fish - Chronic 21 day NOEC (mg l⁻¹)

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

0.001

Daphnia magna

High

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)

Rat

High

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

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

Exposure Routes

Public

Occupational

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

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

May cause pulmonary edema
Potential dyspnea on exertion
May cause blood coagulation disturbance resulting in hematomata

Handling issues

Property

Value and interpretation

General

No information available

CLP classification 2013

Health: H373
Environment: H412

WHO Classification

O (Obsolete substance)

UN Number

Waste disposal & packaging

TRANSLATIONS

Language

Name

English

coumachlor

French

coumachlore

German

Coumachlor

Danish

coumachlor

Italian

cumacloro

Spanish

cumacloro

Greek

coumachlor

Polish

kumachlor

Swedish

Hungarian

Dutch

cumachloor

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