(Also known as: Oil of Allium cepa L.; Allium cepa L. bulb extract)
SUMMARY
Hazard alerts
The following Pesticide Hazard Tricolour (PHT) 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. The alerts for Highly Hazardous Pesticides (HHPs) are based on applying the FAO/WHO (Type 1) and the PAN (Type II) criteria to PPDB data. Further details on the HHP indicators are given in the tables below. Neither the PHT nor the HHP hazard alerts take account of usage patterns or exposure, thus they do not represent risk.
PHT: Environmental fate
PHT: Ecotoxicity
PHT: Human health
Highly Hazardous Pesticide
Human health Moderate alert: Mammals acute toxicity: Moderate
GENERAL INFORMATION
Description
Oil or aqueous extract derived from Allium cepa L. used as an insect repellent or fungicide
Example pests controlled
Carrot root fly (psila rosae); Early blight; Tomato late blight; Grey mold; Common insect pests
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
Onion oil is a complex natural extract than contains variety of sulphur-containing molecules, fatty acids, and volatile organic compounds, some of which exhibit isomerism. For example, its sulphur-containing compounds like thiols, sulphides, and disulphides can exist in structural isomeric forms, depending on how the sulphur atoms are bonded. Fatty acids such as linoleic, oleic, and palmitic acids, present in onion oil, can undergo cis-trans isomerism, especially under heat or light exposure.
As a repellent works via scent masking - aroma originates from plant roots and foliage rich in linoleic, oleic and palmitic acids. Mode of action as a fungicide is unreported.
EU Basic substance under Article 28 of Regulation (EC) No 1107/2009); UK Basic commodity substance implemented under the UK's Plant Protection Products Regulations 2011
Herbicide Resistance Class (HRAC MoA class)
Not applicable
Herbicide Resistance Class (WSSA MoA class)
Not applicable
Insecticide Resistance Class (IRAC MoA class)
Not applicable
Fungicide Resistance Class (FRAC MOA class)
Not applicable
Examples of recorded resistance
Not applicable
Physical state
Oily amber to yellow coloured liquid comprised of various fatty acids dominated by linoleic acid (~65%)
Example manufacturers & suppliers of products using this active now or historically
OnionOil UK
Example products using this active
Onionoil
Formulation and application details
Use in oil dispensers as insect repellent and as a spray when used as a fungicide
Commercial production
Commercial production of onion oil begins with cultivating and harvesting onions. The oil is extracted from the bulbs using steam distillation, which isolates the desirable volatile compounds. Some manufacturers also use solvent extraction for specialised formulations. After extraction, the oil is filtered and refined to ensure purity and consistency.
Impact on climate of production and use
Data for specific plant oils is scarce. However, from publicly available data the carbon footprint of plant oils has been estimated at between 1.0 and 4.0 kg CO₂e per kg of oil. This depends on the plant oil content, agricultural practices and processing methods used.
ENVIRONMENTAL FATE
Property
Value
Source; quality score; and other information
Interpretation
Solubility - In water at 20 °C at pH 7 (mg l⁻¹)
-
-
-
Solubility - In organic solvents at 20 °C (mg l⁻¹)
-
-
-
Melting point (°C)
-
-
-
Boiling point (°C)
-
-
-
Degradation point (°C)
-
-
-
Flashpoint (°C)
41
Q3 Q = Miscellaneous data from online sources 3 = Unverified data of known source
-
Octanol-water partition coefficient at pH 7, 20 °C
P
-
-
-
Log P
-
-
-
Fat solubility of residues
Solubility
-
-
-
Data type
-
-
-
Density (g ml⁻¹)
1.02
Q3 Q = Miscellaneous data from online sources 3 = Unverified data of known source
-
Dissociation constant pKa) at 25 °C
-
-
-
-
Vapour pressure at 20 °C (mPa)
-
-
-
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
-
Soil degradation (days) (aerobic)
DT₅₀ (typical)
-
-
-
DT₅₀ (lab at 20 °C)
-
-
-
DT₅₀ (field)
-
-
-
DT₉₀ (lab at 20 °C)
-
-
-
DT₉₀ (field)
-
-
-
DT₅₀ modelling endpoint
-
-
-
Note
-
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
Kd (mL g⁻¹)
-
-
-
Koc (mL g⁻¹)
-
Notes and range
-
Freundlich
Kf (mL g⁻¹)
-
-
-
Kfoc (mL g⁻¹)
-
1/n
-
Notes and range
-
pH sensitivity
-
Fate indices
Property
Value
Source; quality score; and other information
Interpretation
GUS leaching potential index
-
-
-
SCI-GROW groundwater index (μg l⁻¹) for a 1 kg ha⁻¹ or 1 l ha⁻¹ application rate
Value
Cannot be calculated
-
-
Note
-
Potential for particle bound transport index
-
-
-
Potential for loss via drain flow
-
-
-
Photochemical oxidative DT₅₀ (hrs) as indicator of long-range air transport risk
-
-
-
Bio-concentration factor
BCF (l kg⁻¹)
-
-
-
CT₅₀ (days)
-
-
Known metabolites
None
ECOTOXICOLOGY
Terrestrial ecotoxicology
Property
Value
Source; quality score; and other information
Interpretation
Mammals - Acute oral LD₅₀ (mg kg⁻¹)
> 1000
Q3 Q = Miscellaneous data from online sources 3 = Unverified data of known source
Rat
Moderate
Mammals - Short Term Oral NOAEL (mg kg⁻¹ bw d⁻¹)
-
-
-
Mammals - Long Term (Chronic) Oral NOAEL (mg kg⁻¹ bw d⁻¹)
Regulatory Threshold Levels (RTLs) used to calculate Total Applied Toxicity (TAT)
Species group
RTL
Notes
Mammals
100
Worst case of acute and chronic mammals
Birds
No data
No data for acute and chronic birds
Soil organisms
No data
No data for acute and chronic earthworms
Terrestrial plants
No data
No data for non-target plants vegetative vigour and seedling emergence
Pollinators
No data
No data for contact and oral honeybees
Arthropods
No data
No data for parasitic wasps and predatory mites
Fish
No data
No data for temperate acute and chronic fish
Aquatic invertebrates
No data
No data for temperate acute and chronic aquatic invertebrates
Aquatic plants
No data
No data for free-floating plants, rooted plants, acute and chronic algae
HUMAN HEALTH AND PROTECTION
General
Property
Value
Source; quality score; and other information
Interpretation
Threshold of Toxicological Concern (Cramer Class)
-
-
-
Mammals - Acute oral LD₅₀ (mg kg⁻¹)
> 1000
Q3 Q = Miscellaneous data from online sources 3 = Unverified data of known source
Rat
Moderate
Mammals - Short Term Oral NOAEL (mg kg⁻¹ bw d⁻¹)
-
-
-
Mammals - Long Term (Chronic) Oral NOAEL (mg kg⁻¹ bw d⁻¹)
-
-
-
Mammals - Dermal LD₅₀ (mg kg⁻¹ body weight)
-
-
-
Mammals - Inhalation LC₅₀ (mg l⁻¹)
-
-
-
Other Mammal toxicity endpoints
-
-
-
ADI - Acceptable Daily Intake (mg kg⁻¹ bw day⁻¹)
None allocated
A5 A = EU regulatory and evaluation data as published by EC, EFSA (RAR, DAR & Conclusion dossiers), EMA (e.g. EU Annex III PIC DGD) (EU - Pesticides database; EFSA Scientific Publications ) 5 = Verified data used for regulatory purposes
-
ARfD - Acute Reference Dose (mg kg⁻¹ bw day⁻¹)
None allocated
A5 A = EU regulatory and evaluation data as published by EC, EFSA (RAR, DAR & Conclusion dossiers), EMA (e.g. EU Annex III PIC DGD) (EU - Pesticides database; EFSA Scientific Publications ) 5 = Verified data used for regulatory purposes
A5 A = EU regulatory and evaluation data as published by EC, EFSA (RAR, DAR & Conclusion dossiers), EMA (e.g. EU Annex III PIC DGD) (EU - Pesticides database; EFSA Scientific Publications ) 5 = Verified data used for regulatory purposes
A5 A = EU regulatory and evaluation data as published by EC, EFSA (RAR, DAR & Conclusion dossiers), EMA (e.g. EU Annex III PIC DGD) (EU - Pesticides database; EFSA Scientific Publications ) 5 = Verified data used for regulatory purposes
-
Dermal penetration studies (%)
-
-
-
Dangerous Substances Directive 76/464
-
-
-
Exposure Routes
Public
Minimal risks for the public from proposed uses
Occupational
PPC recommended
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 (hazard-based)
Carcinogen
Genotoxic
Endocrine disruptor
XNo, known not to cause a problem
A0 A = Chromosome aberration (EFSA database) 0 = No data
;
B0 B = DNA damage/repair (EFSA database) 0 = No data
;
C0 C = Gene mutation (EFSA database) 0 = No data
;
D0 D = Genome mutation (EFSA database) 0 = No data
;
E3 E = Unspecified genotoxicity type (miscellaneous data source) 3 = Negative
XNo, known not to cause a problem
Reproduction / development effects
Acetyl cholinesterase inhibitor
Neurotoxicant
XNo, known not to cause a problem
XNo, known not to cause a problem
XNo, known not to cause a problem
Respiratory tract irritant
Skin irritant
Skin sensitiser
✓Yes, known to cause a problem
✓Yes, known to cause a problem
✓Yes, known to cause a problem
Eye irritant
Phototoxicant
✓Yes, known to cause a problem
XNo, known not to cause a problem
General human health issues
Irritant and skin sensitiser
Handling issues
Property
Value and interpretation
General
Flammable liquid when forumated as an oil Use foam or carbon dioxide in firefighting - not water May produce hazardous organic compounds in a fire Not oxidising agent IMDG Transport Hazard Class 3
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
Your use of this website and its various databases is subject to the terms detailed in the University of Hertfordshire’s copyright and IPR statement that can be found at https://www.herts.ac.uk/about-us/legal.
In addition, your use of this website and its various databases is subject to the terms of this additional Copyright Statement and the database Conditions of use document.
Unless explicitly stated otherwise, the content of this website and databases are owned and controlled by the University of Hertfordshire. Site content, including its selection and arrangement, is owned by the University of Hertfordshire and is protected by copyright and other laws.
Except as otherwise expressly permitted under copyright law or within the database Conditions of Use document, the content of this site may not be copied, reproduced, republished, downloaded, posted, broadcast or transmitted in any way without first obtaining the University of Hertfordshire’s written permission.
By using our databases the user is deemed to have agreed to comply with all of the terms and conditions as described above and within all relevant documentation.
Human health
