Dimethirimol (Ref: PP675)

Dimethirimol (Ref: PP675)	Last updated: 14/01/2021
(Also known as: dimethyrimol)

SUMMARY

Dimethirimol is a fungicide without regulatory approval for use in the EU. It has a high aqueous solubility and is quite volatile. Based on its chemical properties, it is may leach to groundwater. It can be persistent in soil systems. Dimethirimol has a low mammalian toxicity. It is moderately toxic to birds and fish.

GENERAL INFORMATION

Description

An eradicant fungicide used in a variety of situations including glasshouses mainly to control powdery mildew

Example pests controlled

Powdery mildew

Example applications

Curcubits; Tobacco; Tomatoes; Barley seed; Cucumbers; Ornamentals

Efficacy & activity

Availability status

Current

Introduction & key dates

1968, first reported;1970, first marketed

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

Also used in

Australia

Chemical structure

Isomerism

Chemical formula

C₁₁H₁₉N₃O

Canonical SMILES

CCCCC1=C(NC(=NC1=O)N(C)C)C

Isomeric SMILES

No data

International Chemical Identifier key (InChIKey)

CJHXCRMKMMBYJQ-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C11H19N3O/c1-5-6-7-9-8(2)12-11(14(3)4)13-10(9)15/h5-7H2,1-4H3,(H,12,13,15)

2D structure diagram/image available?

Yes

General status

Pesticide type

Fungicide

Substance group

Pyrimidinol

Minimum active substance purity

Known relevant impurities

Substance origin

Synthetic

Mode of action

Systemic, ergosterol biosynthesis inhibitor. Nucleic acid synthesis - adenosin-deaminase.

CAS RN

5221-53-4

EC number

226-021-7

CIPAC number

245

US EPA chemical code

228200

PubChem CID

21290

Molecular mass

209.29

PIN (Preferred Identification Name)

5-butyl-2-(dimethylamino)-6-methylpyrimidin-4-ol

IUPAC name

5-butyl-2-dimethylamino-6-methylpyrimidin-4-ol

CAS name

5-butyl-2-(dimethylamino)-6-methyl-4(1H)-pyrimidinone

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)

Examples of recorded resistance

Physical state

Colourless needle-shaped crystals

Formulations

Property

Value

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

Milcurb

Example products using this active

ICI
Syngenta

Formulation and application details

Usually supplied as an aqueous liquid or as a concentrate for dilution.

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

1200

High

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

1200000

Chloroform

360000

Xylene

65000

Ethanol

45000

Acetone

Melting point (°C)

102

Boiling point (°C)

Degradation point (°C)

Flashpoint (°C)

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

7.94 X 10⁰¹

Calculated

Log P

1.9

Low

Bulk density (g ml⁻¹)

1.07

Dissociation constant pKa) at 25 °C

Vapour pressure at 20 °C (mPa)

1.46

Low volatility

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

2.55 X 10^-04

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)

120

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

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

Notes and range

Best available data

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

4.25

Calculated

High leachability

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

Value

1.78 X 10⁰⁰

Calculated

Note

Potential for particle bound transport index

Medium

Calculated

Potential for loss via drain flow

Moderately mobile

Calculated

ECOTOXICOLOGY

Property

Value

Source; quality score; and other information

Interpretation

Bio-concentration factor

BCF (l kg⁻¹)

Low risk

Based on LogP < 3

Low risk

CT₅₀ (days)

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

2350

Rat

Low

Mammals - Short term dietary NOEL

(mg kg⁻¹)

Rat 2 year

(ppm diet)

300

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

Birds - Acute LD₅₀ (mg kg⁻¹)

> 4000

Gallus gallus

Low

Birds - Short term dietary (LC₅₀/LD₅₀)

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

Fish - Acute 96 hour LC₅₀ (mg l⁻¹)

Salmo trutta

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)

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)

Non-toxic

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)

2350

Rat

Low

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

400

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

European MRLs

EU MRL pesticide database

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

No further information available

Handling issues

Property

Value and interpretation

General

No information available

CLP classification 2013

Health: H302, H311
Environment: H412

EC Risk Classification

Not classified: Obsolete

EC Safety Classification

Not classified: Obsolete

WHO Classification

III/O (Slightly hazardous / Obsolete substance)

UN Number

Waste disposal & packaging

TRANSLATIONS

Language

Name

English

dimethirimol

French

dimethirimol

German

Dimethirimol

Danish

dimethirimol

Italian

dimetirimol

Spanish

dimetirimol

Greek

Polish

dimetirimol

Swedish

Hungarian

Dutch

Record last updated:	14/01/2021
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