Haloxyfop-P (Ref: DE 535 acid)

Haloxyfop-P (Ref: DE 535 acid)	Last updated: 27/08/2025
(Also known as: haloxyfop-R; haloxyfop-P acid; haloxyfop-R acid)

SUMMARY

Hazard 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. These hazard alerts do not take account of usage patterns or exposure, thus do not represent risk.

Environmental fate	Ecotoxicity	Human health
Environmental fate High alert: Drainflow: Mobile	Ecotoxicity Moderate alert: Birds acute ecotoxicity: Moderate; Fish acute ecotoxicity: Moderate; Fish chronic ecotoxicity: Moderate; Daphnia chronic ecotoxicity: Moderate; Earthworms acute ecotoxicity: Moderate	Human health Moderate alert: Mammals acute toxicity: Moderate

GENERAL INFORMATION

Description

A post-emergence herbicide used to control annual and perennial grass weeds. Also a pesticide transformation product.

Example pests controlled

Annual and perennial grass weeds

Example applications

Orchards; Soybeans; Sugarbeet; Oilseed rape; Sunflower; Cotton; Bananas; Non-crop situations; Forestry

Efficacy & activity

GB regulatory status

GB COPR regulatory status

Not approved

Date COPR inclusion expires

Expired

GB LERAP status

No UK approval for use as a plant protection agent

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status

Not approved

Dossier rapporteur/co-rapporteur

Denmark

Date EC 1107/2009 inclusion expires

Expired

EU Candidate for substitution (CfS)

Not applicable

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

Haloxyfop-P exhibits chiral isomerism, specifically existing as the R-enantiomer of haloxyfop. The molecule contains a single chiral centre at the carbon adjacent to the carboxylic acid group, which allows for two enantiomers: R and S. Only the R-isomer, known as haloxyfop-P, possesses significant herbicidal activity. Originally, haloxyfop was marketed as a racemic mixture (containing both R and S forms), but commercial formulations now favour the stereospecific R-isomer to enhance efficacy and reduce environmental load.

Chemical formula

C₁₅H₁₁ClF₃NO₄

Canonical SMILES

CC(C(=O)O)OC1=CC=C(C=C1)OC2=C(C=C(C=N2)C(F)(F)F)Cl

Isomeric SMILES

C[C@H](C(=O)O)OC1=CC=C(C=C1)OC2=C(C=C(C=N2)C(F)(F)F)Cl

International Chemical Identifier key (InChIKey)

GOCUAJYOYBLQRH-MRVPVSSYSA-N

International Chemical Identifier (InChI)

InChI=1S/C15H11ClF3NO4/c1-8(14(21)22)23-10-2-4-11(5-3-10)24-13-12(16)6-9(7-20-13)15(17,18)19/h2-8H,1H3,(H,21,22)/t8-/m1/s1/f/h21H

2D structure diagram/image available?

Yes

General status

Pesticide type

Herbicide; Metabolite

Metabolite Type

Soil; Groundwater

Substance groups

Aryloxyphenoxypropionate herbicide

Minimum active substance purity

940 g kg⁻¹

Known relevant impurities

Substance origin

Synthetic

Mode of action

Selective, absorbed by roots and foliage. Acetyl CoA carboxylase inhibitor (ACCase) - distrupts fatty acid biosynthesis and lipid formation.

CAS RN

95977-29-0

EC number

619-184-4

CIPAC number

526

US EPA chemical code

PubChem CID

448979

CLP index number

No data found

Molecular mass

361.7

PIN (Preferred Identification Name)

IUPAC name

(R)-2-{4-[3-chloro-5-(trifluoromethyl)-2-pyridyloxy]phenoxy}propionic acid

CAS name

(2R)-2-[4-[[3-chloro-5-(trifluoromethyl)-2-pyridinyl]oxy]phenoxy]propanoic acid

Forever chemical

Other status information

Relevant Environmental Water Quality Standards

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

Off-white powder

Related substances & organisms

haloxyfop-P-methyl

Can be a metabolite of:

Parent

Formation medium

Estimated maximum occurrence fraction

1107/2009 relevancy

haloxyfop-P-methyl

Soil

0.91

Major fraction

haloxyfop-P-methyl

Soil

0.91

Major fraction

Commercial

Property

Value

Availability status

Current

Introduction & key dates

circa 1993, introduced

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

Dow AgroSciences

Example products using this active

Gallant Super

Formulation and application details

Usually supplied as an emulsifiable concentrate, as the methyl variant, that is diluted with water and applied as a broadcast spray

Commercial production

Haloxyfop-P tends to be used and produced as the methyl variant. The commercial production of haloxyfop-P-methyl involves a multi-step synthetic process designed to yield the biologically active R-enantiomer with high optical purity. It begins with the preparation of a substituted hydroquinone, which undergoes etherification with a chiral alkylating agent, typically (R)-2-bromopropionic acid methyl ester, to introduce the stereocentre. This intermediate is then reacted with a halogenated pyridine derivative, such as 3-chloro-2-bromo-5-trifluoromethylpyridine, under controlled conditions to form the key pyridyloxy linkage. The resulting compound is purified and esterified to produce haloxyfop-P-methyl.

Impact on climate of production and use

Data for the amount of life cycle GHGs produced by Haloxyfop-P are not available in the public domain. However, whilst estimates vary, more general data suggests that between 18 and 27 kilograms of CO₂e is emitted per kilogram of herbicide produced.

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

375

Moderate

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

2000000

Acetone

2000000

Methanol

639000

Xylene

3930

n-Heptane

Melting point (°C)

72.5

Boiling point (°C)

Degradation point (°C)

Flashpoint (°C)

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

1.86 X 10⁰⁰

Calculated

Log P

0.27

Low

Fat solubility of residues

Solubility

Soluble

Data type

Regulatory data - observed in metabolism and farm animal feeding studies

Density (g ml⁻¹)

1.46

Dissociation constant pKa) at 25 °C

4.27

Weak acid

Vapour pressure at 20 °C (mPa)

4.00 X 10^-03

at 25 °C

Low volatility

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

5.10 X 10^-09

Non-volatile

Volatilisation as max % of applied dose lost

From plant surface

From soil surface

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

Acidic solution: 274.8nm = 10300, 223.5nm = 16700, 202.0nm = 20300

Surface tension (mN m⁻¹)

41.0

Degradation

Property

Value

Source; quality score; and other information

Interpretation

General biodegradability

Soil degradation (days) (aerobic)

DT₅₀ (typical)

23.9

Non-persistent

DT₅₀ (lab at 20 °C)

23.9

Non-persistent

DT₅₀ (field)

Non-persistent

DT₉₀ (lab at 20 °C)

128

Persistent

DT₉₀ (field)

DT₅₀ modelling endpoint

Note

EU dossier lab studies DT₅₀ range 13.0-35.9 days, DT₉₀ range 31-332 days; field studies Europe DT₅₀ range 12-19 days

Dissipation rate RL₅₀ (days) on plant matrix

Value

Note

Dissipation rate RL₅₀ (days) on and in plant matrix

Value

Note

Aqueous photolysis DT₅₀ (days) at pH 7

Value

Moderately fast

Note

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

Value

Stable

Note

Stable at pH9

Water-sediment DT₅₀ (days)

0.1

Fast

Water phase only DT₅₀ (days)

0.2

Fast

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)

0.79

Mobile

K_oc (mL g⁻¹)

Notes and range

EU dossier K_d range 0.06-1.59 mL g⁻¹, K_oc range 42.5-113.5 mL g⁻¹, Soils=10

Freundlich

K_f (mL g⁻¹)

Moderately mobile

K_foc (mL g⁻¹)

110.8

¹/_n

0.936

Notes and range

EU dossier K_foc range 27-352 mL g⁻¹, ¹/_n range 0.913-0.956

pH sensitivity

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

2.41

Calculated

Transition state

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

Value

9.64 X 10^-02

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)

Low potential

CT₅₀ (days)

Known soil metabolites

Metabolite

Major/Minor fraction

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

Estimated maximum occurrence fraction

Notes

4-(3-chloro-5-trifluoromethyl-2-pyridyloxyphenol)

Major fraction

0.126

3-chloro-5-trifluoromethylpyridin-2-ol

Major fraction

0.52

3-chloro-1-methyl-5-(trifluoromethyl)-2(1H)-pyridinone

Major fraction

0.11

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)

>= 300

Rat

Moderate

Mammals - Short term dietary NOEL

(mg kg⁻¹)

0.2

Dog

High

(ppm diet)

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

Birds - Acute LD₅₀ (mg kg⁻¹)

414

Anas platyrhynchos

Moderate

Birds - Short term dietary (LC₅₀/LD₅₀)

> 5000 mg kg feed⁻¹

Anas platyrhynchos

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

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

415

Eisenia foetida corr

Moderate

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

Soil micro-organisms

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

Dose: 16 x field rate 28 Day

Collembola

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

Non-target plants

Vegetative vigour ER₅₀ (g ha⁻¹)

Seedling emergence ER₅₀ (g ha⁻¹)

Honeybees (Apis spp.)

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

> 100

Low

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

> 100

Low

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)

100% Mortality at dose 0.108 kg ha⁻¹

Aphidius rhopalosiphi

Beneficial insects (Predatory mites)

91% Mortality at dose 0.108 kg ha⁻¹

Typhlodromus pyri

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)

> 50

Oncorhynchus mykiss

Moderate

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

0.86

Pimephales promelas

Moderate

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)

9.6

Daphnia magna

Moderate

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, fonds growth, fresh) - 7 day (mg l⁻¹) (EC₅₀)

5.4

Lemna minor

Moderate

Aquatic plants (rooted, growth rate, fresh) - 14 day (mg l⁻¹)

Algae - Acute (growth rate, fresh; mg l⁻¹) (96 hr EC₅₀)

47.2

Raphidocelis subcapitata

Low

Algae - Chronic (growth rate, fresh; mg l⁻¹)

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)

>= 300

Rat

Moderate

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

2000

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

Other Mammal toxicity endpoints

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

0.00065

Rat SF=100

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

0.075

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)

0.005

Dermal penetration studies (%)

7-12

concentration dependent

Dangerous Substances Directive 76/464

Exposure Routes

Public

No unacceptable risks to bystanders identified

Occupational

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

MRLs

European

EU MRL pesticide database

Great Britain

GB MRL Register

Notes

Amendment to GB MRL expected June 2025

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

; ; ; ;

No data found

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 and thyroid toxicant

Handling issues

Property

Value and interpretation

General

Not explosive
Not expected to auto-ignite; Not highly flammable

CLP classification 2013

Health: H301
Environment: H412

WHO Classification

II (Moderately hazardous)

UN Number

Waste disposal & packaging

Shelf-life, storage, stability and reactivity

TRANSLATIONS

Language

Name

English

haloxyfop-P

French

haloxyfop-R

German

Haloxyfop-R

Danish

haloxyfop-R

Italian

Spanish

haloxifop-R

Greek

Polish

haloksyfop-P

Swedish

Hungarian

haloxifob-R

Dutch

haloxyfop-R

Norwegian

Record last updated:	27/08/2025
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