2,4-D-dimethylammonium

2,4-D-dimethylammonium	Last updated: 28/02/2025
(Also known as: 2,4-D dimethyl amine salt)

SUMMARY

2,4-D-dimethylammonium is selective phenoxy herbicide and plant growth regulator. Data related specifically to the dimethylammonium variant is limited but a fuller dataset is available as 2,4-D.

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: GUS: High leachability; Drainflow: Mobile	Ecotoxicity Moderate alert: Birds chronic ecotoxicity: Moderate; Bees acute oral ecotoxicity: Moderate; Earthworms acute ecotoxicity: Moderate; Earthworms chronic ecotoxicity: Moderate	Human health High alert: Genotoxic; Reproduction/development effects

GENERAL INFORMATION

Description

A translocated phenoxy herbicide for use in cereals, grass and amenity use.

Example pests controlled

Broad-leaved weeds, Evasive weeds in aquatic situations

Example applications

Turf grass & pastures; Non-cropping situations; Amenity sites; Almonds; Orchards; Cereals including barley, wheat and oats; Lucerne

Efficacy & activity

Availability status

Current

Introduction & key dates

cira 1950, introduced

GB regulatory status

GB COPR regulatory status

Approved

Date COPR inclusion expires

31/12/2030

GB LERAP status

Check label - may vary with formulation

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status

Approved

Dossier rapporteur/co-rapporteur

Greece/Poland

Date EC 1107/2009 inclusion expires

31/12/2030

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

C₁₀H₁₃Cl₂NO₃

Canonical SMILES

CNC.C1=CC(=C(C=C1Cl)Cl)OCC(=O)O

Isomeric SMILES

International Chemical Identifier key (InChIKey)

IUQJDHJVPLLKFL-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C8H6Cl2O3.C2H7N/c9-5-1-2-7(6(10)3-5)13-4-8(11)12;1-3-2/h1-3H,4H2,(H,11,12);3H,1-2H3

2D structure diagram/image available?

Yes

Cambridge Crystallographic Data Centre diagrams

Common Name	Relationship	Link
2,4-D	Parent

General status

Pesticide type

Herbicide, Plant Growth Regulator

Substance groups

Phenoxy herbicide; Phenoxy PGR; Auxin PGR

Minimum active substance purity

Known relevant impurities

Substance origin

Synthetic

Mode of action

Selective, systemic, absorbed through roots and increases biosynthesis and production of ethylene causing uncontrolled cell division and so damages vascular tissue. Synthetic auxin.

CAS RN

2008-39-1

EC number

217-915-8

CIPAC number

US EPA chemical code

030019

PubChem CID

16180

CLP index number

No data found

Molecular mass

266.12

PIN (Preferred Identification Name)

(2,4-dichlorophenoxy)acetic acid—N-methylmethanamine (1/1)

IUPAC name

dimethylammonium (2,4-dichlorophenoxy)acetate

CAS name

2-(2,4-dichlorophenoxy)acetic acid compound with N-methylmethanamine (1:1)

Other status information

Relevant Environmental Water Quality Standards

UK statutory standard for protection of aquatic life for inland, coastal & territorial surface waters: 1.0 µg l⁻¹ as annual mean conc

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

Related substances & organisms

2,4-D

2,4-D-ammonium

2,4-D-choline

2,4-D-diolamine

2,4-D-etexyl

2,4-D-isopropylammonium

Formulations

Property

Value

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

Example products using this active

Formulation and application details

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

24300

as 2,4-D

High

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

Melting point (°C)

Boiling point (°C)

Degradation point (°C)

Flashpoint (°C)

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

1.51 X 10^-01

Calculated

Log P

-0.82

as 2,4-D

Low

Fat solubility of residues

Solubility

Data type

Density (g ml⁻¹)

Dissociation constant pKa) at 25 °C

Vapour pressure at 20 °C (mPa)

0.009

as 2,4-D

Low volatility

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

Volatilisation as max % of applied dose lost

From plant surface

From soil surface

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

Not readiliy biodegradable

Soil degradation (days) (aerobic)

DT₅₀ (typical)

4.4

as 2,4-D

Non-persistent

DT₅₀ (lab at 20 °C)

4.4

as 2,4-D

Non-persistent

DT₅₀ (field)

28.8

as 2,4-D

Non-persistent

DT₉₀ (lab at 20 °C)

DT₉₀ (field)

DT₅₀ modelling endpoint

Note

EU dossier data for 2,4-D

Dissipation rate RL₅₀ (days) on plant matrix

Value

Note

Dissipation rate RL₅₀ (days) on and in plant matrix

Value

1.7

Note

Wheat straw, n=1

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)

Sediment phase only DT₅₀ (days)

Air degradation

As this parameter is not normally measured directly, a surrogate measure is used: ‘Photochemical oxidative DT₅₀’. Where data is available, this can be found in the Fate Indices section below.

Decay in stored produce DT₅₀

Soil adsorption and mobility

Property

Value

Source; quality score; and other information

Interpretation

Linear

K_d (mL g⁻¹)

0.7

as 2,4-D

Mobile

K_oc (mL g⁻¹)

39.3

Notes and range

EU dossier data for 2,4-D

Freundlich

K_f (mL g⁻¹)

0.45

as 2,4-D

Mobile

K_foc (mL g⁻¹)

¹/_n

0.83

Notes and range

EU dossier data for 2,4-D

pH sensitivity

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

3.82

Calculated

High leachability

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

Value

6.92 X 10^-01

Calculated

Note

Potential for particle bound transport index

Low

Calculated

Potential for loss via drain flow

Mobile

Calculated

Photochemical oxidative DT₅₀ (hrs) as indicator of long-range air transport risk

Bio-concentration factor

BCF (l kg⁻¹)

CT₅₀ (days)

Known soil metabolites

Metabolite

Major/Minor fraction

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

Estimated maximum occurrence fraction

Notes

2,4-D (Ref: L 208)

Major fraction

1.00

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)

> 639

Rat

Moderate

Mammals - Short term dietary NOEL

(mg kg⁻¹)

(ppm diet)

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

Birds - Acute LD₅₀ (mg kg⁻¹)

> 5620

Anas platyrhynchos

Low

Birds - Short term dietary (LC₅₀/LD₅₀)

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

> 100

Colinus virginianus as 2,4-D

Moderate

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

350

Eisenia foetida as 2,4-D

Moderate

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

62.5

Eisenia foetida as 2,4-D

Moderate

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)

> 100

Apis mellifera as 2,4-D

Low

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

Apis mellifera as 2,4-D

Moderate

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

Chronic

Notes

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

Temperate Freshwater Fish - Acute 96 hour LC₅₀ (mg l⁻¹)

> 495

Pimephales promelas

Low

Temperate Freshwater Fish - Chronic 21 day NOEC (mg l⁻¹)

17.1

Pimephales promelas 31 day

Low

Tropical Freshwater Fish - Acute 96 hour LC₅₀ (mg l⁻¹)

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

> 100

Daphnia magna

Low

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

Tropical Freshwater Aquatic invertebrates - Acute 48 hour EC₅₀ (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 (free-floating, growth) - Acute 7 day EC₅₀, biomass (mg l⁻¹)

Aquatic plants (rooted, growth) - Acute 14 day EC₅₀, biomass (mg l⁻¹)

0.5

Myriophyllum spicatum 42d

Moderate

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

> 60.7

Pseudokirchneriella subcapitata

Low

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

3.1

Green algae 4 days

Low

Mesocosm study data

NOEAEC mg l⁻¹

Marine bivalves

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)

> 639

Rat

Moderate

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

1829

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

Other Mammal toxicity endpoints

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

0.05

Rat SF=100 as 2,4-D

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

None allocated

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

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

0.15

Rat SF=100 as 2,4-D

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

; ; ; ;

Reproduction / development effects

Acetyl cholinesterase inhibitor

Neurotoxicant

Respiratory tract irritant

Skin irritant

Skin sensitiser

Eye irritant

Phototoxicant

No data found

General human health issues

Possible liver, kidney & blood toxicant
IARC Group 2B carcinogen
Possible negative impacts on endocrine system

Handling issues

Property

Value and interpretation

General

Not explosive or oxidising
IMDG Transport Hazard Class 9
Not expected to auto-ignite; Not highly flammable

CLP classification 2013

Health: H302, H317, H318, H335
Environment: H411

WHO Classification

Not listed (Not listed)

UN Number

UN3077

Waste disposal & packaging

Packaging Group III (minor danger)

Shelf-life, storage, stability and reactivity

TRANSLATIONS

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English

2,4-D-dimethylammonium

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Record last updated:	28/02/2025
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