Cinmethylin (Ref: SD 95481)

Cinmethylin (Ref: SD 95481)	Last updated: 05/05/2021
(Also known as: WL 95481; cinch)

SUMMARY

Cinmethylin is a selective pre-emergence rice herbicide without EU or UK regulatory approval for use. It is moderately soluble in water, is quite volatile and, based on its chemical properties, it is non-mobile and would not be expected to leach to groundwater. It may be persistent in both soil and aquatic systems. It is not susceptible to hydrolysis. It is not acutely toxic to mammals but it is an eye and skin irritant. It shows a moderate level of toxicity to birds, fish and daphnia.

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 High alert: Potential for particle bound transport: High	Ecotoxicity Moderate alert: Birds acute ecotoxicity: Moderate; Fish acute ecotoxicity: Moderate; Daphnia acute ecotoxicity: Moderate	Human health Low alert Warning: Significant data are missing

GENERAL INFORMATION

Description

Pre-emergence herbicide used to control annual grass weeds mainly in rice

Example pests controlled

Barnyard grass; Velvetleaf; Crabgrass; Pigweed; Annual ryegrass

Example applications

Rice; Soybeans

Efficacy & activity

Availability status

Current

Introduction & key dates

1989

UK regulatory status

UK COPR regulatory status

Not approved

Date COPR inclusion expires

Not applicable

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

Not applicable

EU Candidate for substitution (CfS)

Not applicable

Listed in EU database

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

A chiral molecule with three stereocenters. The technical material is an isomeric mixture.

Chemical formula

C₁₈H₂₆O₂

Canonical SMILES

CC1=CC=CC=C1COC2CC3(CCC2(O3)C)C(C)C

Isomeric SMILES

No data

International Chemical Identifier key (InChIKey)

QMTNOLKHSWIQBE-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C18H26O2/c1-13(2)18-10-9-17(4,20-18)16(11-18)19-12-15-8-6-5-7-14(15)3/h5-8,13,16H,9-12H2,1-4H3/t16-,17+,18-/m1/s1

2D structure diagram/image available?

Yes

General status

Pesticide type

Herbicide

Substance group

Cineole

Minimum active substance purity

Known relevant impurities

Substance origin

Synthetic

Mode of action

Selective, systemic, absorbed by roots and translocated. Disrupts the meristemic development in shoots and roots of susceptible weeds.

CAS RN

87818-31-3

EC number

402-410-9

CIPAC number

None allocated

US EPA chemical code

128837

PubChem CID

91745

Molecular mass

274.40

PIN (Preferred Identification Name)

(1RS,2SR,4SR)-1,4-epoxy-p-menth-2-yl 2-methylbenzyl ether

IUPAC name

(1RS,2SR,4SR)-1,4-epoxy-p-menth-2-yl 2-methylbenzyl ether

CAS name

(1R,2S,4S)-rel-1-methyl-4-(1-methylethyl)-2-[(2-methylphenyl)methoxy]-7-oxabicyclo[2.2.1]heptane

Other status information

Relevant Environmental Water Quality Standards

Herbicide Resistance Classification (HRAC)

Herbicide Resistance Classification (WSSA)

Insecticide Resistance Classification (IRAC)

Not applicable

Fungicide Resistance Classification (FRAC)

Not applicable

Examples of recorded resistance

Physical state

Dark orange liquid, colourless in pure form

Formulations

Property

Value

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

Argold
Cinch

Example products using this active

BASF
Dupont

Formulation and application details

Usually supplied as an emusifiable concentrate or as granules

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

Ethyl acetate

Melting point (°C)

Decomposes before melting

Boiling point (°C)

Decomposes before boiling

Degradation point (°C)

145

Flashpoint (°C)

147

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

6.92 X 10⁰³

Calculated

Log P

3.84

High

Bulk density (g ml⁻¹)

1.014

Dissociation constant pKa) at 25 °C

Vapour pressure at 20 °C (mPa)

10.1

Highly volatile

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

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)

Moderately persistent

DT₅₀ (lab at 20 °C)

DT₅₀ (field)

Moderately persistent

DT₉₀ (lab at 20 °C)

DT₉₀ (field)

DT₅₀ modelling endpoint

Note

Literature values DT₅₀ range 23-75 days; slower in paddy fields

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

Stable

Note

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

Value

Stable

Note

Stable pH 3 to pH 11 at 25 °C.

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

6850

Notes and range

Other data source: 300 mL g⁻¹ (US3)

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

0.24

Calculated

Low leachability

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

Value

7.07 X 10^-03

Calculated

Note

Potential for particle bound transport index

High

Calculated

Potential for loss via drain flow

Non-mobile

Calculated

ECOTOXICOLOGY

Property

Value

Source; quality score; and other information

Interpretation

Bio-concentration factor

BCF (l kg⁻¹)

CT₅₀ (days)

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

> 4553

Rat

Low

Mammals - Short term dietary NOEL

(mg kg⁻¹)

Rat

(ppm diet)

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

Birds - Acute LD₅₀ (mg kg⁻¹)

> 1600

Colinus virginianus

Moderate

Birds - Short term dietary (LC₅₀/LD₅₀)

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

Fish - Acute 96 hour LC₅₀ (mg l⁻¹)

> 6.6

Oncorhynchus mykiss

Moderate

Fish - Chronic 21 day NOEC (mg l⁻¹)

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

> 7.2

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)

Non-target plants

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

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

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)

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

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

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

Other soil macro-organisms

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

Other arthropod (1)

LR₅₀ g ha⁻¹

% Effect

Other arthropod (2)

LR₅₀ g ha⁻¹

% Effect

Soil micro-organisms

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)

> 4553

Rat

Low

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

2000

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

3.5

Rat 4 hr

Other Mammal toxicity endpoints

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

0.3

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

Notes

Drinking Water Standards

Drinking Water MAC (μg l⁻¹)

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

Gastrointestinal or liver toxicant

Handling issues

Property

Value and interpretation

General

No information available

CLP classification 2013

EC Risk Classification

Xn - Harmful: R20
N - Dangerous for the environment: R51, R53

EC Safety Classification

S2, S23, S61

WHO Classification

III (Slightly hazardous)

UN Number

Waste disposal & packaging

TRANSLATIONS

Language

Name

English

cinmethylin

French

cimmethyline

German

Danish

Italian

Spanish

Greek

Polish

cynmetylina

Swedish

Hungarian

Dutch

Record last updated:	05/05/2021
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