Aminopyralid (Ref: XDE 750)

Aminopyralid (Ref: XDE 750)	Last updated: 04/01/2021
(Also known as: 4-amino-3,6-dichloropicolinic acid; DE 750; XR 750; GF-839)

SUMMARY

Aminopyralid is a pyridine carboxylic acid herbicide that is currently under approval consideration for use in the EU. It is non-volatile, highly soluble in water and, based on its chemical properties, is mobile and has a high potential for leaching to groundwater. It may be moderately persistent in soil systems but would not be expected to persistent in surface water under normal conditions. It has a low mammalian toxicity and there is some concern regarding its potential for bioaccumulation. Aminopyralid has a low to moderate toxicity to most terrestrial and aquatic species.

GENERAL INFORMATION

Description

A pyridine carboxylic acid herbicide for the long-term control of noxious and invasive broad-leaved weeds in grassland

Example pests controlled

Broomweed; Buttercups; Cocklebur; Daisy; Fleabane; Knapweed; Ragweed; Ragwort; Lambsquarter

Example applications

Rangeland; Permanent grass; Non-cropped areas including paths; roadways

Efficacy & activity

Availability status

Current

Introduction & key dates

2005

UK regulatory status

UK COPR regulatory status

Approved

Date COPR inclusion expires

31/12/2024

UK LERAP status

None

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status

Approved

Dossier rapporteur/co-rapporteur

Date EC 1107/2009 inclusion expires

31/12/2024

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, USA (pending)

Chemical structure

Isomerism

Chemical formula

C₆H₄Cl₂N₂O₂

Canonical SMILES

C1=C(C(=C(N=C1Cl)C(=O)O)Cl)N

Isomeric SMILES

No data

International Chemical Identifier key (InChIKey)

NIXXQNOQHKNPEJ-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C6H4Cl2N2O2/c7-3-1-2(9)4(8)5(10-3)6(11)12/h1H,(H2,9,10)(H,11,12)/f/h11H,9H2

2D structure diagram/image available?

Yes

General status

Pesticide type

Herbicide

Substance group

Pyridine compound

Minimum active substance purity

920 g kg⁻¹

Known relevant impurities

EU dossier - None declared

Substance origin

Synthetic

Mode of action

Systemic, post-emergence action, absorbed by leaves and roots, some residual action

CAS RN

150114-71-9

EC number

CIPAC number

771

US EPA chemical code

005100

PubChem CID

213012

Molecular mass

207.03

PIN (Preferred Identification Name)

4-amino-3,6-dichloropyridine-2-carboxylic acid

IUPAC name

4-amino-3,6-dichloropyridine-2-carboxylic acid

CAS name

4-amino-3,6-dichloro-2-pyridinecarboxylic acid

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

Off-white powder

Related substances & organisms

fluroxypyr

triclopyr

2,4-D

fluroxypyr

Formulations

Property

Value

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

CleanWave
Forefront
Pharoah
Milestone
Banish

Example products using this active

Dow Agrosciences

Formulation and application details

Often available as an oil in water concentrate that is mixed with water and used as a spray.

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

2480

High

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

29200

Acetone

3940

Ethyl acetate

52200

Methanol

Xylene

Melting point (°C)

163.5

Boiling point (°C)

Decomposes before boiling

Degradation point (°C)

334

Flashpoint (°C)

Not expected to self ignite; Not highly flammable

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

1.35 X 10^-03

Calculated

Log P

-2.87

Low

Bulk density (g ml⁻¹)

1.76

Dissociation constant pKa) at 25 °C

2.56

Strong acid

Vapour pressure at 20 °C (mPa)

2.59 X 10^-09

Low volatility

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

9.61 X 10^-12

Non-volatile

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

At pH 1.4 maxima = 217nm
At pH 5 maxima = 217nm
At pH 12.6 maxima = 220nm

Surface tension (mN m⁻¹)

71.0

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)

55.5

Moderately persistent

DT₅₀ (field)

12.1

Non-persistent

DT₉₀ (lab at 20 °C)

185

Persistent

DT₉₀ (field)

40.2

DT₅₀ modelling endpoint

Note

EU dossier lab studies DT₅₀ range 26.4-146.9 days, DT₉₀ range 87.6-488 days, field studies DT₅₀ range 3.75-21.6 days, DT₉₀ range 12.5-71.8 days; Manufacturer lab data DT₅₀ 9-54 days; Other literature Lab studies range 31.5-533.2 days, 5 soils

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

0.6

Fast

Note

DT₅₀: 0.6 days at pH 5. Main route of degradation on aquatic environments

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

Value

Stable

Note

Stable pH 5 to pH 9 at temps 20 and 50 °C

Water-sediment DT₅₀ (days)

712

Stable

Water phase only DT₅₀ (days)

250

Stable

Soil adsorption and mobility

Property

Value

Source; quality score; and other information

Interpretation

Linear

K_d

K_oc

Notes and range

Freundlich

K_f

0.17

Very mobile

K_foc

8.3

¹/_n

0.852

Notes and range

EU dossier K_f range 0.01-0.73 mL g⁻¹, K_foc range 0.31-21.7 mL g⁻¹, ¹/_n range 0.32-1.52, Soils=8

pH sensitivity

Adsorption higher at low pH

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

3.34

Calculated

High leachability

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

Value

1.60 X 10^-01

Calculated

Note

Potential for particle bound transport index

Low

Calculated

Potential for loss via drain flow

Very mobile

Calculated

ECOTOXICOLOGY

Property

Value

Source; quality score; and other information

Interpretation

Bio-concentration factor

BCF (l kg⁻¹)

100

Threshold for concern

CT₅₀ (days)

Not available

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

> 5000

Rat

Low

Mammals - Short term dietary NOEL

(mg kg⁻¹)

> 465

Rat

Moderate

(ppm diet)

> 1000

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

1000

Unknown species Reproductive NOAEL

Low

Birds - Acute LD₅₀ (mg kg⁻¹)

> 2250

Colinus virginianus

Low

Birds - Short term dietary (LC₅₀/LD₅₀)

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

185.6

Unknown species

Moderate

Fish - Acute 96 hour LC₅₀ (mg l⁻¹)

> 100

Oncorhynchus mykiss

Low

Fish - Chronic 21 day NOEC (mg l⁻¹)

1.3

Pimephales promelas

Moderate

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)

100

Americamysis bahia

Moderate

Sediment dwelling organisms - Acute 96 hour LC₅₀ (mg l⁻¹)

Sediment dwelling organisms - Chronic 28 day NOEC, static, water (mg l⁻¹)

130

Chironomus riparius

Low

Sediment dwelling organisms - Chronic 28 day NOEC, sediment (mg kg⁻¹)

46.7

Chironomus riparius

Moderate

Aquatic plants - Acute 7 day EC₅₀, biomass (mg l⁻¹)

Lemna gibba

Low

Non-target plants

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

Pseudokirchneriella subcapitata

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)

> 6.26

Apis mellifera

Moderate

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

> 3.13

Apis mellifera

Moderate

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)

> 1000

Eisenia foetida

Low

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

21.5

Mortality [Dose: 0.03 kg ha⁻¹]
Aphidius rhopalosiphi

Other arthropod (2)

LR₅₀ g ha⁻¹

% Effect

12.6

Mortality [Dose: 0.08 kg ha⁻¹]
Typhlodromus pyri

Soil micro-organisms

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

Dose: 100x field rate for grassland

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)

> 5000

Rat

Low

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

5000

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

5.5

Rat 4 hr

Other Mammal toxicity endpoints

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

0.26

proposed Rabbit SF=100

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

0.26

proposed 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)

0.26

proposed Rabbit SF=100

Dermal penetration studies (%)

UK ACP

Dangerous Substances Directive 76/464

Exposure Routes

Public

Low risk to bystanders

Occupational

Acceptable risk to operators with PPE/PPC
Low risk to other farm workers

MRLs

European

EU MRL pesticide database

Notes

Drinking Water Standards

Drinking Water MAC (μg l⁻¹)

0.1

EU Dir 89/778/EC limit; Calc MAC=4260 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

May damage the corneal resulting in permanent impairment of vision and blindness

Handling issues

Property

Value and interpretation

General

Flammable
Corrosive

CLP classification 2013

Health: H315, H318, H319, H335
Environment: H400, H410

EC Risk Classification

Xn - Harmful: R41

EC Safety Classification

WHO Classification

U (Unlikely to present an acute hazard)

UN Number

Waste disposal & packaging

TRANSLATIONS

Language

Name

English

aminopyralid

French

aminopyralid

German

Aminopyralid

Danish

aminopyralid

Italian

aminopyralid

Spanish

aminopiralida

Greek

Polish

aminopiralid

Swedish

aminopyralid

Hungarian

Dutch

Record last updated:	04/01/2021
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