Dichlorprop-P (Ref: BAS 044H)

Dichlorprop-P (Ref: BAS 044H)	Last updated: 12/01/2021
(Also known as: AHM867; 2,4-DP-P; CA3121)

SUMMARY

A commonly used herbicide approved for use in most of the developed world. It is highly soluble in water, has a low volatility and is quite mobile. It is not usually persistent in soil or sediment systems. It is not expected to bioaccumulate, has a moderate mammalian oral toxicity and may ne a skin and eye irritant. It is moderately toxic to mammals, birds and aquatic plants but less so to fish, aquatic invertebrates, bees and earthworms.

GENERAL INFORMATION

Description

A post-emergence herbicide particularly effective for brush and broad-leaved weed control. Also used as plant growth regulator for increasing fruit size on citrus

Example pests controlled

Black bindweed; Hawthorne; Wild cherry; Wild raspberry; Horsetail; Teasel; Spotted ladysthumb; Smartweed; Canada thistle; Goosefoot; Stink weed; Cocklebur; Docks; Kochia

Example applications

Cereals including wheat, barley, oats, triticale, rye; Non-cropped land; Fruit especially citrus (growth), apple & pear orchards (weed control)

Efficacy & activity

Dichlorprop-P is a long established and proven herbicide.

Availability status

Current

Introduction & key dates

1987

UK regulatory status

UK COPR regulatory status

Approved

Date COPR inclusion expires

30/04/2024

UK LERAP status

None

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status

Approved

Dossier rapporteur/co-rapporteur

Ireland/Poland

Date EC 1107/2009 inclusion expires

30/04/2021

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

Chemical structure

Isomerism

The R-enantiomer of the chiral dichlorprop molecule

Chemical formula

C₉H₈Cl₂O₃

Canonical SMILES

CC(C(=O)O)OC1=C(C=C(C=C1)Cl)Cl

Isomeric SMILES

C[C@H](C(=O)O)OC1=C(C=C(C=C1)Cl)Cl

International Chemical Identifier key (InChIKey)

MZHCENGPTKEIGP-RXMQYKEDSA-N

International Chemical Identifier (InChI)

InChI=1S/C9H8Cl2O3/c1-5(9(12)13)14-8-3-2-6(10)4-7(8)11/h2-5H,1H3,(H,12,13)/t5-/m1/s1

2D structure diagram/image available?

Yes

Cambridge Crystallographic Data Centre diagrams

Common Name	Relationship	Link
dichlorprop-P	-

General status

Pesticide type

Herbicide, Plant growth regulator

Substance group

Aryloxyalkanoic acid

Minimum active substance purity

920 g kg⁻¹

Known relevant impurities

EU dossier - 2,4-dichlorophenol < 5g kg⁻¹; Other phenoxy acids

Substance origin

Synthetic

Mode of action

Selective, systemic, absorbed by leaves and translocates to roots. Synthetic auxin causing stem and leaf malformations leading to death.

CAS RN

15165-67-0

EC number

403-980-1

CIPAC number

476

US EPA chemical code

031402

PubChem CID

119435

Molecular mass

235.06

PIN (Preferred Identification Name)

(2R)-2-(2,4-dichlorophenoxy)propanoic acid

IUPAC name

(R)-2-(2,4-dichlorophenoxy)propionic acid

CAS name

(2R)-2-(2,4-dichlorophenoxy)propanoic acid

Other status information

Potential groundwater contaminant

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

White crystalline solid

Related substances & organisms

dicamba

MCPA

iron sulphate

dichlorprop-P 2-ethylyhexyl ester

Can be a metabolite of:

Parent

Formation medium

Estimated maximum occurrence fraction

1107/2009 relevancy

dichlorprop-P 2-ethylyhexyl ester

Soil

0.916

Major fraction; Relevant

Formulations

Property

Value

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

Link
Optica
Duplosan DP
Corasil

Example products using this active

Headland
Scotts
Nufarm

Formulation and application details

Often supplied as a soluble concentrate which is mixed with water and applied as a spray

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

672

High

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

1679000

Acetone

697000

Ethyl acetate

1631000

Methanol

2900

n-Heptane

Melting point (°C)

122.1

Boiling point (°C)

Decomposes before boiling

Degradation point (°C)

222

Flashpoint (°C)

Not expected to self ignite; Not highly flammable

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

4.68 X 10⁰⁰

Calculated

Log P

0.67

Low

Bulk density (g ml⁻¹)

1.42

Dissociation constant pKa) at 25 °C

3.5

Weak acid

Vapour pressure at 20 °C (mPa)

0.056

Low volatility

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

5.60 X 10^-05

Non-volatile

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

205nm = 28000, 218nm = 7600, 230nm = 8900, 252nm = 2200, 285nm = 1900, 292nm = 1700 (shoulder)

Surface tension (mN m⁻¹)

60.5

Degradation

Property

Value

Source; quality score; and other information

Interpretation

General biodegradability

Readily biodegradable

Soil degradation (days) (aerobic)

DT₅₀ (typical)

Non-persistent

DT₅₀ (lab at 20 °C)

Non-persistent

DT₅₀ (field)

DT₉₀ (lab at 20 °C)

69.6

Moderately persistent

DT₉₀ (field)

DT₅₀ modelling endpoint

54.6

Reasonable worse case

Note

EU 2017 dossier lab studies DT₅₀ range 6.6-19.5 days, DT₉₀ range 23.8-181 days, Soils=5

Dissipation rate RL₅₀ on plant matrix

Value

Note

Dissipation rate RL₅₀ on and in plant matrix

Value

2.2

Note

Wheat, whole plant, n=1

Aqueous photolysis DT₅₀ (days) at pH 7

Value

3.2

Moderately fast

Note

Natural light, 30DegN,

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

Value

Stable

Note

Stable pH 5 to pH 9

Water-sediment DT₅₀ (days)

Fast

Water phase only DT₅₀ (days)

Slow

Soil adsorption and mobility

Property

Value

Source; quality score; and other information

Interpretation

Linear

K_d

Mobile

K_oc

Notes and range

EU 2002 dossier range 12.9-83.7 mL g⁻¹

Freundlich

K_f

0.54

Mobile

K_foc

36.0

¹/_n

0.80

Notes and range

EU 2017 dossier K_f range 0.105-1.68 mL g⁻¹, K_foc range 12.9-81.5 mL g⁻¹, ¹/_n range 0.65-0.91, Soils=11

pH sensitivity

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

2.64

Calculated

Transition state

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

Value

8.71 X 10^-02

Calculated

Note

Potential for particle bound transport index

Low

Calculated

Potential for loss via drain flow

Mobile

Calculated

Key metabolites

Metabolite

Formation medium

Estimated maximum occurrence fraction

1107/2009 relevancy

2,4-dichlorophenol

Soil (photolysis)

0.236

Major fraction; relevant

2,4-dichloroanisole

Soil

0.042

Minor fraction, Relevant

Other known metabolites

Metabolite name and reference

Aliases

Formation medium / Rate

Estimated maximum occurrence fraction

Metabolising enzymes

dichlorprop-P-methyl ester

dichlorprop-P metabolite 11

Plant

dichlorprop-OH

Plant

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)

567

Rat

Moderate

Mammals - Short term dietary NOEL

(mg kg⁻¹)

152

Rat

Moderate

(ppm diet)

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

Unknown species Reproductive NOAEL

Moderate

Birds - Acute LD₅₀ (mg kg⁻¹)

250

Colinus virginianus

Moderate

Birds - Short term dietary (LC₅₀/LD₅₀)

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

142.1

Coturnix japonica (females acid) NOAEL

Moderate

Fish - Acute 96 hour LC₅₀ (mg l⁻¹)

> 109

Oncorhynchus mykiss

Low

Fish - Chronic 21 day NOEC (mg l⁻¹)

> 100

Oncorhynchus mykiss

Low

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

> 100

Daphnia magna

Low

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

> 100

Daphnia magna

Low

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)

4.1

Lemna gibba

Moderate

Non-target plants

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

Raphidocelis subcapitata

Low

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

>= 11

Skeletonema costatum

Low

Honeybees (Apis spp.)

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

> 200

Apis mellifera

Low

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

> 200

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)

> 500

Eisenia foetida corr

Moderate

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

309

Eisenia foetida corr

Low

Other soil macro-organisms

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

1.25

Folsomia candida corr

Other arthropod (1)

LR₅₀ g ha⁻¹

% Effect

Mortality [Dose: 1.5 kg ha⁻¹]
Aphidius rhopalosiphi juvenile

Other arthropod (2)

LR₅₀ g ha⁻¹

% Effect

33 / 18

Mortality / Fecundity [Dose: 1.5 kg ha⁻¹]
Typhlodromus pyri adult/juvenile

Soil micro-organisms

Nitrogen mineralisation: No significant adverse effect [Dose: 7.5 kg ha⁻¹]
Carbon mineralisation: No significant adverse effect [Dose: 1.5 kg ha⁻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)

567

Rat

Moderate

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

4000

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

> 7.4

Rat 4hr

Other Mammal toxicity endpoints

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

0.06

Mouse SF=100

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

0.5

Rabbit SF=100

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

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

0.35

Rat 90 day SF=100

Dermal penetration studies (%)

19-45

concentration dependent

Dangerous Substances Directive 76/464

Exposure Routes

Public

Negligible risk to bystanders and residents

Occupational

PPE/PPC recommened to reduce exposure risk

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

; ; ; ;

Reproduction / development effects

Acetyl cholinesterase inhibitor

Neurotoxicant

Respiratory tract irritant

Skin irritant

Skin sensitiser

Eye irritant

Phototoxicant

General human health issues

Highly toxic
Potential kidney, liver & blood toxicant
May cause severe eye damage
May trigger allergic reactions

Handling issues

Property

Value and interpretation

General

Not explosive or oxidising
IMDG Transport Code is usually 3

CLP classification 2013

Health: H302, H315, H317, H318

EC Risk Classification

Xn - Harmful: R22, R41, R43
Xi - Irritant: R38

EC Safety Classification

S2, S24, S26, S37/39

WHO Classification

NL (Not listed)

UN Number

Usually 1648

Waste disposal & packaging

Packaging Group II (medium danger)

TRANSLATIONS

Language

Name

English

dichlorprop-P

French

dichlorprop-P

German

Dichlorprop-P

Danish

dichlorprop-P

Italian

diclorprop-P

Spanish

diclorprop-P

Greek

dichlorprop-P

Polish

dichlorprop-P

Swedish

diklorprop-P

Hungarian

dichlorprop-P

Dutch

dichloorprop-P

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