Chlorthiamid (Ref: WL 5792.)

Chlorthiamid (Ref: WL 5792.)	Last updated: 01/09/2023
(Also known as: chloriamide; DCBN)

SUMMARY

Chlorthiamid is an obsolete pre-emergence herbicide once used for non-selective weed control. It is highly soluble in water and is non-volatile. It is not persistent in soil systems and considered to be moderately mobile, and so it may leach to groundwater under certain conditions. Its toxicity to flora and fauma tends to be low to moderate. It also has a low mammalian toxicity. Little information is available on chlorthiamids potential for serious adverse health effects.

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: GUS: Transition state; Drainflow: Moderately mobile Warning: Significant data are missing	Ecotoxicity Moderate alert: Birds acute ecotoxicity: Moderate; Fish acute ecotoxicity: Moderate; Daphnia acute ecotoxicity: Moderate; Bees acute contact ecotoxicity: Moderate	Human health Moderate alert: Mammals acute toxicity: Moderate Warning: Significant data are missing

GENERAL INFORMATION

Description

An obsolete pre-emergence herbicide once used for non-selective weed control

Example pests controlled

Quackgrass; Barnyard grass; Crab grass; Horsetail; Pigweed; Chickweed; Plaintain; Nightshade; Dandelion; Lambsquarters

Example applications

Orchards; Grapes; Berry crops; Forestry; Non-cropped areas including roadsides, pathways, industrial sites

Efficacy & activity

Availability status

Considered obsolete but may be available in some countries

Introduction & key dates

1964, first reported

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

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

Chemical structure

Isomerism

None

Chemical formula

C₇H₅Cl₂NS

Canonical SMILES

C1=CC(=C(C(=C1)Cl)C(=S)N)Cl

Isomeric SMILES

No data

International Chemical Identifier key (InChIKey)

KGKGSIUWJCAFPX-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C7H5Cl2NS/c8-4-2-1-3-5(9)6(4)7(10)11/h1-3H,(H2,10,11)

2D structure diagram/image available?

Yes

General status

Pesticide type

Herbicide

Substance groups

Benzonitrile herbicide; Thioamide herbicide

Minimum active substance purity

Known relevant impurities

Substance origin

Synthetic

Mode of action

Systemic, absorbed by roots and leaves, acting against germinating seeds. Inhibits cell wall synthesis

CAS RN

1918-13-4

EC number

217-637-7

CIPAC number

US EPA chemical code

326300

PubChem CID

2734819

CLP index number

616-005-00-1

Molecular mass

206.09

PIN (Preferred Identification Name)

2,6-dichlorobenzenecarbothioamide

IUPAC name

2,6-dichlorothiobenzamide

CAS name

2,6-dichlorobenzenecarbothioamide

Other status information

Relevant Environmental Water Quality Standards

Herbicide Resistance Class (HRAC MoA class)

Herbicide Resistance Class (WSSA MoA class)

Insecticide Resistance Class (IRAC MoA class)

Not applicable

Fungicide Resistance Class (FRAC MOA class)

Not applicable

Examples of recorded resistance

Physical state

Off-white solid

Formulations

Property

Value

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

Hodogaya Chemical Co.
Shell Research Ltd

Example products using this active

Prefix

Formulation and application details

Usually supplied as a granular or wettable powder formulations.

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

950

High

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

Melting point (°C)

151

Boiling point (°C)

Degradation point (°C)

Flashpoint (°C)

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

5.89 X 10⁰¹

Calculated

Log P

1.77

Low

Fat solubility of residues

Solubility

Data type

Density (g ml⁻¹)

1.47

Dissociation constant pKa) at 25 °C

Vapour pressure at 20 °C (mPa)

0.13

Low volatility

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

2.82 X 10^-05

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)

Non-persistent

DT₅₀ (lab at 20 °C)

DT₅₀ (field)

DT₉₀ (lab at 20 °C)

DT₉₀ (field)

DT₅₀ modelling endpoint

Note

Best available data

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

Stable

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

Moderately mobile

K_oc

241

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

2.26

Calculated

Transition state

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

Value

9.69 X 10^-02

Calculated

Note

Potential for particle bound transport index

Low

Calculated

Potential for loss via drain flow

Moderately mobile

Calculated

Bio-concentration factor

BCF (l kg⁻¹)

Low risk

Based on LogP < 3

Low risk

CT₅₀ (days)

Known soil metabolites

Metabolite

Major/Minor fraction

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

Estimated maximum occurrence fraction

Notes

dichlobenil (Ref: H 133)

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)

757

Rat

Moderate

Mammals - Short term dietary NOEL

(mg kg⁻¹)

Rat

(ppm diet)

100

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

Birds - Acute LD₅₀ (mg kg⁻¹)

500

Gallus domesticus

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)

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)

77.3

Moderate

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 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

Fish - Acute 96 hour LC₅₀ (mg l⁻¹)

Rasbora heteromorpha

Moderate

Fish - Chronic 21 day NOEC (mg l⁻¹)

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

56.0

Daphnia magna

Moderate

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)

17.0

Unknown species

Low

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)

757

Rat

Moderate

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

1000

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

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

Harmful if swallowed

Handling issues

Property

Value and interpretation

General

Prevent generation of dust
Gives off irritating fumes in a fire

CLP classification 2013

Health: H302

WHO Classification

II (Moderately hazardous)

UN Number

Waste disposal & packaging

Shelf-life, storage, stability and reactivity

TRANSLATIONS

Language

Name

English

chlorthiamid

French

chlorthiamide

German

Chlorthiamid

Danish

chlorthiamid

Italian

cloritiamid

Spanish

clortiamid

Greek

chlorthiamid

Polish

chlortiamid

Swedish

Hungarian

Dutch

chloorthiamide

Norwegian

Record last updated:	01/09/2023
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