Pelargonic acid

Pelargonic acid	Last updated: 22/06/2025
(Also known as: nonanoic acid ; capsaicin II; fatty acids C7 to C20; fatty acid)

SUMMARY

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 Moderate alert: Drainflow: Moderately mobile	Ecotoxicity Moderate alert: Fish acute ecotoxicity: Moderate; Daphnia acute ecotoxicity: Moderate; Daphnia chronic ecotoxicity: Moderate; Earthworms acute ecotoxicity: Moderate	Human health Low alert Warning: Significant data are missing

GENERAL INFORMATION

Description

Plant-derived substance with multiple uses including general weed control, fruit thinning in orchards and vineyards, as a potato post-harvest desiccant, and for clearing woody weeds from paths etc.

Example pests controlled

Broad spectrum of weeds and plant growth

Example applications

Fruit

Efficacy & activity

Efficacy established via field trials and extensive use

Availability status

Current

Introduction & key dates

1992, first registered USA

GB regulatory status

GB COPR regulatory status

Approved

Date COPR inclusion expires

31/08/2029

GB LERAP status

None

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status

Approved

Dossier rapporteur/co-rapporteur

Greece/Austria

Date EC 1107/2009 inclusion expires

11/12/2026

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

USA

Chemical structure

Isomerism

Chemical formula

C₉H₁₈O₂

Canonical SMILES

CCCCCCCCC(=O)O

Isomeric SMILES

No data

International Chemical Identifier key (InChIKey)

FBUKVWPVBMHYJY-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C9H18O2/c1-2-3-4-5-6-7-8-9(10)11/h2-8H2,1H3,(H,10,11)

2D structure diagram/image available?

Yes

Cambridge Crystallographic Data Centre diagrams

Common Name	Relationship	Link
pelargonic acid	-

General status

Pesticide type

Herbicide; Plant Growth Regulator; Other substance

Other bioactivity & uses

Rain-fast agent; Adjuvant; Biocide; Disinfectant

Substance groups

Plant-derived substance

Minimum active substance purity

>89.6% w/w

Known relevant impurities

EU 2020 RAR dossier: Hexanoic acid, Heptanoic acid & Octanoic acid combined total < 50 g kg⁻¹

Substance origin

Natural

Mode of action

Phyotoxic, contact action, broad-spectrum

CAS RN

112-05-0

EC number

203-931-2

CIPAC number

888

US EPA chemical code

217500

PubChem CID

Molecular mass

158.2

PIN (Preferred Identification Name)

IUPAC name

1-octanecarboxylic acid

CAS name

1-octanecarboxylic acid

Other status information

EU approval as a disinfectant until March 2028

Relevant Environmental Water Quality Standards

Herbicide Resistance Class (HRAC MoA class)

Not known

Herbicide Resistance Class (WSSA MoA class)

Not known

Insecticide Resistance Class (IRAC MoA class)

Not applicable

Fungicide Resistance Class (FRAC MOA class)

Not applicable

Examples of recorded resistance

Physical state

Clear to yellow oily liquid

Related substances & organisms

fatty acids (generic C7-C18)

isobutyric acid

isovaleric acid

valeric acid

capric acid

caprylic acid

Can be a metabolite of:

Parent

Formation medium

Estimated maximum occurrence fraction

1107/2009 relevancy

capsaicin

Soil

Formulations

Property

Value

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

Doff Portland
STV International
Witax Ltd

Example products using this active

Superfast longlasting weed killer
Time's up
Ultima
Safer's Insecticidal Soap
Neudosan New
Endital AF

Formulation and application details

Usually supplied as a liquid concentrate

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

415

at pH5

Moderate

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

250000

n-Heptane

250000

p-Xylene

250000

Methanol

250000

Acetone

Melting point (°C)

11.7

Boiling point (°C)

258

Degradation point (°C)

Flashpoint (°C)

133

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

1.70 X 10⁰²

Calculated

Log P

2.23

Low

Fat solubility of residues

Solubility

Data type

Density (g ml⁻¹)

Dissociation constant pKa) at 25 °C

4.94

Weak acid

Vapour pressure at 20 °C (mPa)

452

Highly volatile. If applied directly to plants or soil, drift is a concern & mitigation is advisable

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

0.04

Non-volatile

Volatilisation as max % of applied dose lost

From plant surface

From soil surface

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

At pH2: 207.99nm=60
At pH7: 207.97nm=63
At pH10 - no absorption

Surface tension (mN m⁻¹)

32.0

99.6% at 20°C

Degradation

Property

Value

Source; quality score; and other information

Interpretation

General biodegradability

Soil degradation (days) (aerobic)

DT₅₀ (typical)

1.3

Non-persistent

DT₅₀ (lab at 20 °C)

1.28

Non-persistent

DT₅₀ (field)

DT₉₀ (lab at 20 °C)

5.11

Non-persistent

DT₉₀ (field)

DT₅₀ modelling endpoint

Note

EU 2020 Dossier: Lab study DT₅₀ (normalised) range 0.7-1.58 days; DT₉₀ (measured) 4.95-5.28 days, Soils=4

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

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)

K_oc (mL g⁻¹)

Notes and range

Freundlich

K_f (mL g⁻¹)

3.25

Moderately mobile

K_foc (mL g⁻¹)

139.5

¹/_n

1.09

Notes and range

EU 2020 dossier: K_d range 0.08-13.11 mL g⁻¹; K_foc range 8.1-569.9 mL g⁻¹; ¹/_n range 0.97-1.3, Soils=5

pH sensitivity

Yes

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

0.20

Calculated

Low leachability

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

Value

6.69 X 10^-04

Calculated

Note

Potential for particle bound transport index

Low

Calculated

Potential for loss via drain flow

Moderately mobile

Calculated

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

1.1

Calculated using the Atkinson method

Below the level of concern for long-range air transport

Bio-concentration factor

BCF (l kg⁻¹)

101

Threshold for concern

CT₅₀ (days)

n/a

Known metabolites

None

ECOTOXICOLOGY

Terrestrial ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

> 2000

Rat

Low

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)

2450

Colinus virginianus

Low

Birds - Short term dietary (LC₅₀/LD₅₀)

> 5620 ppm

Anas platyrhynchos

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

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

> 105

Eisenia foetida corr

Moderate

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

250

Eisenia foetida corr

Low

Soil micro-organisms

Collembola

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

Non-target plants

2.5

Solanum lycopersicum
Vegetative vigour ER₅₀
as kg ha⁻¹

Honeybees (Apis spp.)

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

> 181.1

Apis mellifera

Low

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

122.1

Apis mellifera

Low

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

Chronic as 10-day LDD₅₀ µg bee⁻¹ day⁻¹

48.0

Apis mellifera

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) as Mortality LR₅₀ g ha⁻¹

> 10310

Chrysoperla carnea

Beneficial insects (Parasitic wasps) as Mortality LR₅₀ g ha⁻¹

< 3.9

Aphidius rhopalosiphi

Beneficial insects (Predatory mites) as Mortality LR₅₀ g ha⁻¹

198

Typhlodromus pyri

Beneficial insects (Ground beetles) as Mortality LR₅₀ g ha⁻¹

> 10310

Poecilus cupreus

Aquatic ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

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

> 11.5

Oncorhynchus mykiss

Moderate

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

16.2

Oncorhynchus mykiss

Low

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

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

10.0

Daphnia magna

Moderate

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

0.38

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)

> 100

Chironomus riparius 48 hr

Low

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)

> 60.2

Lemna gibba

Low

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

> 140.4

Myriophyllum spicatum

Low

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

16.8

Scenedesmus subspicatus

Low

Algae - Chronic 96 hour NOEC, growth (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)

Low (class I)

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

> 2000

Rat

Low

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

2000

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

> 5.0

Rat

Other Mammal toxicity endpoints

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

None allocated

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

None allocated

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

None allocated

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

None allocated

Dermal penetration studies (%)

25-70%

concentration dependent

Dangerous Substances Directive 76/464

Exposure Routes

Public

Very low risk considerting intended uses

Occupational

Very low risk considerting intended uses

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

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

May cause eye damage

Handling issues

Property

Value and interpretation

General

Not explosive or oxidising
Not highly flammable
Corrosive

CLP classification 2013

Health: H315, H318
Environment: H412

WHO Classification

Not listed (Not listed)

UN Number

Waste disposal & packaging

Shelf-life, storage, stability and reactivity

TRANSLATIONS

Language

Name

English

pelargonic acid

French

German

Danish

Italian

Spanish

Greek

Polish

Swedish

pelargonsyra

Hungarian

Dutch

Norwegian

pelargonsyre

Record last updated:	22/06/2025
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