Mepiquat chloride (Ref: BAS 083W)

Mepiquat chloride (Ref: BAS 083W)	Last updated: 12/01/2021
(Not known by any other names)

GENERAL INFORMATION

Description

A plant growth regulator used to reduce vegetative growth including sprout suppression in onions, leeks and garlic

Example pests controlled

Growth; Strength

Example applications

Cereals including wheat, oats, barley, rye, triticale; Cotton; Onions; Leeks; Garlic; Grass

Efficacy & activity

Efficacy demonsrated from extensive global use and field research

Availability status

Current

Introduction & key dates

1980, USA

UK regulatory status

UK COPR regulatory status

Approved

Date COPR inclusion expires

28/02/2024

UK LERAP status

None

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status

Approved

Dossier rapporteur/co-rapporteur

Finland/Estonia

Date EC 1107/2009 inclusion expires

28/02/2021

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
✓		✓	✓		✓	✓		✓

Also used in

Australia

Chemical structure

Isomerism

None

Chemical formula

C₇H₁₆ClN

Canonical SMILES

C[N+]1(CCCCC1)C.[Cl-]

Isomeric SMILES

No data

International Chemical Identifier key (InChIKey)

VHOVSQVSAAQANU-UHFFFAOYSA-M

International Chemical Identifier (InChI)

InChI=1S/C7H16N.ClH/c1-8(2)6-4-3-5-7-8;/h3-7H2,1-2H3;1H/q+1;/p-1

2D structure diagram/image available?

Yes

General status

Pesticide type

Plant growth regulator

Substance group

Quarternary ammonium compound

Minimum active substance purity

575 g kg⁻¹

Known relevant impurities

EU dossier - None declared

Substance origin

Synthetic

Mode of action

Inhibits biosynthesis of gibberellic acid

CAS RN

24307-26-4

EC number

246-147-6

CIPAC number

440.302

US EPA chemical code

109101

PubChem CID

62781

Molecular mass

149.66

PIN (Preferred Identification Name)

IUPAC name

1,1-dimethylpiperidinium chloride

CAS name

1,1-dimethylpiperidinium chloride

Other status information

Relevant Environmental Water Quality Standards

Herbicide Resistance Classification (HRAC)

None allocated

Herbicide Resistance Classification (WSSA)

None allocated

Insecticide Resistance Classification (IRAC)

Not applicable

Fungicide Resistance Classification (FRAC)

Not applicable

Examples of recorded resistance

Physical state

Colourless crystals

Related substances & organisms

chlormequat chloride

prohexadione-calcium

mepiquat

Formulations

Property

Value

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

Stronghold
Terpal
Chamatkar
Pix

Example products using this active

BASF
King Tech Corp
Makhteshim Agan

Formulation and application details

Often supplied as an aqueous solution

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

747000

High

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

487000

Methanol

Toluene

Acetone

n-Heptane

Melting point (°C)

Decomposes before melting

Boiling point (°C)

Decomposes before boiling

Degradation point (°C)

320

Flashpoint (°C)

Not expected to self ignite; Not flammable

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

2.82 X 10^-04

Calculated

Log P

-3.55

Low

Bulk density (g ml⁻¹)

1.16

Dissociation constant pKa) at 25 °C

Not applicable

Completely dissociates in aqueous solution

Vapour pressure at 20 °C (mPa)

1.00 X 10^-05

Low volatility

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

2.99 X 10^-12

Non-volatile

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

No significant absorption between 200-750nm at pH 1, 6 or 13

Surface tension (mN m⁻¹)

47.4

Degradation

Property

Value

Source; quality score; and other information

Interpretation

General biodegradability

Not readily biodegradable

Soil degradation (days) (aerobic)

DT₅₀ (typical)

13.3

Non-persistent

DT₅₀ (lab at 20 °C)

13.3

Non-persistent

DT₅₀ (field)

DT₉₀ (lab at 20 °C)

85.1

Moderately persistent

DT₉₀ (field)

DT₅₀ modelling endpoint

Note

EU 2018 dossier lab studies DT₅₀ (actual) range 3.55-74.5 days, DT₉₀ (actual) range 29.8-247.5 days, Soils=7

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 9

Water-sediment DT₅₀ (days)

32.5

Moderately fast

Water phase only DT₅₀ (days)

7.5

Moderately fast

Soil adsorption and mobility

Property

Value

Source; quality score; and other information

Interpretation

Linear

K_d

K_oc

Notes and range

Freundlich

K_f

9.03

Slightly mobile

K_foc

890

¹/_n

0.968

Notes and range

K_f range 0.22-25.0, K_foc range 67-4833 mL g⁻¹, ¹/_n range 0.914-1.634, Soils=12

pH sensitivity

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

1.18

Calculated

Low leachability

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

Value

1.98 X 10^-02

Calculated

Note

Potential for particle bound transport index

Low

Calculated

Potential for loss via drain flow

Slightly mobile

Calculated

Other known metabolites

Metabolite name and reference

Aliases

Formation medium / Rate

Estimated maximum occurrence fraction

Metabolising enzymes

4-hydroxymepiquat chloride

Rat; Animal

Agrobacterium radiobacter strain K84

Animal

methyl piperidine

Animal

ECOTOXICOLOGY

Property

Value

Source; quality score; and other information

Interpretation

Bio-concentration factor

BCF (l kg⁻¹)

Whole fish

Low potential

CT₅₀ (days)

Not available

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

200

Rat

Moderate

Mammals - Short term dietary NOEL

(mg kg⁻¹)

Rat

(ppm diet)

3000

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

> 155

Rat Reproductive NOAEL

Moderate

Birds - Acute LD₅₀ (mg kg⁻¹)

> 2000

Colinus virginianus

Low

Birds - Short term dietary (LC₅₀/LD₅₀)

> 1326 mg kg bw⁻¹ day⁻¹

Colinus virginianus

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

> 100.7

Coturnix japonica NOAEL

Moderate

Fish - Acute 96 hour LC₅₀ (mg l⁻¹)

> 100

Oncorhynchus mykiss

Low

Fish - Chronic 21 day NOEC (mg l⁻¹)

100

Oncorhynchus mykiss 28 day

Low

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

68.5

Daphnia magna

Moderate

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

12.5

Daphnia magna

Low

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

136.0

Americamysis bahia

Low

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)

2.6

Lemna gibba

Moderate

Non-target plants

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

14.4

Anabaena flos-aquae

Low

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)

> 100

Apis mellifera

Low

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

> 107.4

Apis mellifera

Low

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)

319.5

Eisenia foetida

Moderate

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

31.25

Eisenia foetida

Moderate

Other soil macro-organisms

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

Other arthropod (1)

LR₅₀ g ha⁻¹

1366

48 hour
Aphidius rhopalosiphi

% Effect

Other arthropod (2)

LR₅₀ g ha⁻¹

1530

>, 7 day
Typhlodromus pyri

% Effect

Soil micro-organisms

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

Dose: 8.14 mg kg⁻¹ soil

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)

200

Rat

Moderate

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

2000

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

> 4.89

Rat

Other Mammal toxicity endpoints

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

0.065

Rat SF=200

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

0.3

Rat SF=100

AAOEL - Acute Acceptable Operator Exposure Level (mg kg⁻¹ bw day⁻¹)

0.225

Rat SF=100

AOEL - Acceptable Operator Exposure Level - Systemic (mg kg⁻¹ bw day⁻¹)

0.075

Rat SF=500

Dermal penetration studies (%)

25-75

concentration dependant

Dangerous Substances Directive 76/464

Exposure Routes

Public

Minimal risk from dietary exposure
Risk assessment indicates ARfD would not normally be exceded

Occupational

Risk of exposure acceptable under label recommendations for use for personal protection clothing and equipment

European MRLs

EU MRL pesticide database

Drinking Water Standards

Drinking Water MAC (μg l⁻¹)

0.1

EU Dir 89/778/EC limit; Calc MAC=900 µg l⁻¹

Health issues

Specific human health issues

Carcinogen

Genotoxic

Endocrine disruptor

; ; ; ;

No data found

Reproduction / development effects

Acetyl cholinesterase inhibitor

Neurotoxicant

Respiratory tract irritant

Skin irritant

Skin sensitiser

No data found

Eye irritant

Phototoxicant

No data found

General human health issues

Moderately toxic
May effect hematological parameters

Handling issues

Property

Value and interpretation

General

Prevent generation of mists
Not explosive or oxidising

CLP classification 2013

Health: H302
Environment: H412

EC Risk Classification

Xn - Harmful: R22
N - Dangerous for the environment: R52, R53

EC Safety Classification

S2, S61

WHO Classification

II (Moderately hazardous)

UN Number

Waste disposal & packaging

TRANSLATIONS

Language

Name

English

mepiquat chloride

French

mepiquat-chlorure

German

Mepiquat chlorid

Danish

mepiquat-chlorid

Italian

mepiquat cloruro

Spanish

cloruro de mepicuat

Greek

Polish

chlorek mepikwatu

Swedish

mepikvatklorid

Hungarian

Dutch

Record last updated:	12/01/2021
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