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
Environmental fate Moderate alert: Drainflow: Moderately mobile
Warning: Significant data are missing
Ecotoxicity Moderate alert: Fish acute ecotoxicity: Moderate
Warning: Significant data are missing
Human health Moderate alert: Mammals acute toxicity: Moderate; Reproduction/development effects
GENERAL INFORMATION
Description
A plant-derived substance common in many essential oils and which demonstrates insecticidal, fungicide, antimicrobial and herbicidal activities
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
Citral exists as a mixture of two geometric isomers: geranial (trans-citral or E-isomer, approximately 60-70% in natural sources) and neral (cis-citral or Z-isomer, approximately 30-40%).
Example manufacturers & suppliers of products using this active now or historically
BASF
Example products using this active
-
Formulation and application details
-
Commercial production
Citral is commercially produced on a large scale through synthetic routes.The key intermediate is isoprenol (3-methyl-3-buten-1-ol), formed by addition of formaldehyde to isobutene. Isoprenol undergoes oxidative dehydrogenation (often over silver catalysts) to yield a mixture of prenal and related compounds, followed by isomerisation steps to prenol and prenal. These react under acidic catalysis to form an unsaturated acetal, which then undergoes thermal cleavage and rearrangement to produce citral as a roughly 1:1 mixture of geranial (E-isomer) and neral (Z-isomer). Historically and to a lesser extent today, natural citral is extracted by steam distillation or fractionation from essential oils of plants.
Impact on climate of production and use
-
ENVIRONMENTAL FATE
Property
Value
Source; quality score; and other information
Interpretation
Solubility - In water at 20 °C at pH 7 (mg l⁻¹)
1340
Q3 Q = Miscellaneous data from online sources 3 = Unverified data of known source
at 25 °C
High
Solubility - In organic solvents at 20 °C (mg l⁻¹)
-
-
-
Melting point (°C)
-
-
-
Boiling point (°C)
92
F3 F = U.S. EPA ECOTOX database / U.S. EPA pesticide fate database / Miscellaneous WHO documents / FAO data, IPCS INCHEM data (US EPA Databases Related to Pesticide Risk Assessment ) 3 = Unverified data of known source
-
Degradation point (°C)
-
-
-
Flashpoint (°C)
82
F3 F = U.S. EPA ECOTOX database / U.S. EPA pesticide fate database / Miscellaneous WHO documents / FAO data, IPCS INCHEM data (US EPA Databases Related to Pesticide Risk Assessment ) 3 = Unverified data of known source
(closed cup)
-
Octanol-water partition coefficient at pH 7, 20 °C
P
7.41 X 1002
Calculated
-
Log P
2.87
F3 F = U.S. EPA ECOTOX database / U.S. EPA pesticide fate database / Miscellaneous WHO documents / FAO data, IPCS INCHEM data (US EPA Databases Related to Pesticide Risk Assessment ) 3 = Unverified data of known source
Moderate
Fat solubility of residues
Solubility
-
-
-
Data type
-
-
-
Density (g ml⁻¹)
0.891
F3 F = U.S. EPA ECOTOX database / U.S. EPA pesticide fate database / Miscellaneous WHO documents / FAO data, IPCS INCHEM data (US EPA Databases Related to Pesticide Risk Assessment ) 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
Readily biodegradable
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)
-
F3 F = U.S. EPA ECOTOX database / U.S. EPA pesticide fate database / Miscellaneous WHO documents / FAO data, IPCS INCHEM data (US EPA Databases Related to Pesticide Risk Assessment ) 3 = Unverified data of known source
estimated
Moderately mobile
Koc (mL g⁻¹)
83
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
Moderately mobile
Calculated
-
Photochemical oxidative DT₅₀ (hrs) as indicator of long-range air transport risk
-
-
-
Bio-concentration factor
BCF (l kg⁻¹)
10
Q3 Q = Miscellaneous data from online sources 3 = Unverified data of known source
Low potential
CT₅₀ (days)
-
-
Known soil and groundwater metabolites
None
Other known metabolites
Metabolite name and reference
Aliases
Formation medium / Rate
Estimated maximum occurrence fraction
3-hydroxy-3,7-dimethyl-6-octenedioic acid
-
Mammal urinary
-
3,8-dihydroxy-3,7-dimethyl-6-octenolc acid
-
Mammal urinary
-
3,9-dihydroxy-3,7-dimethyl-6-octenolc acid
-
Mammal urinary
-
E/Z-3,7-dimethyl-2,6-octadienedioic acid
-
Mammal urinary
-
3,7-dimethyl-6-octenedioic acid
-
Mammal urinary
-
E-3,7-dimethyl-2,6-octadienoic acid
-
Mammal urinary
-
ECOTOXICOLOGY
Terrestrial ecotoxicology
Property
Value
Source; quality score; and other information
Interpretation
Mammals - Acute oral LD₅₀ (mg kg⁻¹)
> 1440
F3 F = U.S. EPA ECOTOX database / U.S. EPA pesticide fate database / Miscellaneous WHO documents / FAO data, IPCS INCHEM data (US EPA Databases Related to Pesticide Risk Assessment ) 3 = Unverified data of known source
Mouse
Moderate
Mammals - Short Term Oral NOAEL (mg kg⁻¹ bw d⁻¹)
200
F3 F = U.S. EPA ECOTOX database / U.S. EPA pesticide fate database / Miscellaneous WHO documents / FAO data, IPCS INCHEM data (US EPA Databases Related to Pesticide Risk Assessment ) 3 = Unverified data of known source
Rat NOAEL
Low
Mammals - Long Term (Chronic) Oral NOAEL (mg kg⁻¹ bw d⁻¹)
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)
-
-
-
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)
-
-
-
Beneficial insects (Butterflies)
Contact
-
-
-
Notes
-
Oral
-
-
-
Notes
-
Aquatic ecotoxicology
Property
Value
Source; quality score; and other information
Interpretation
Temperate Freshwater Fish - Acute 96 hour LC₅₀ (mg l⁻¹)
> 4.1
F3 F = U.S. EPA ECOTOX database / U.S. EPA pesticide fate database / Miscellaneous WHO documents / FAO data, IPCS INCHEM data (US EPA Databases Related to Pesticide Risk Assessment ) 3 = Unverified data of known source
Oryzias latipes
Moderate
Temperate Freshwater Fish - Chronic 21 day NOEC (mg l⁻¹)
-
-
-
Tropical Freshwater Fish - Acute 96 hour LC₅₀ (mg l⁻¹)
Note: These RTLs have been calculated using the regulatory approach used in the European Union and based on ecotoxocity values in the PPDB.
Species group
RTL
Notes
Mammals
40
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
0.041
Worst case of 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)
> 1440
F3 F = U.S. EPA ECOTOX database / U.S. EPA pesticide fate database / Miscellaneous WHO documents / FAO data, IPCS INCHEM data (US EPA Databases Related to Pesticide Risk Assessment ) 3 = Unverified data of known source
Mouse
Moderate
Mammals - Short Term Oral NOAEL (mg kg⁻¹ bw d⁻¹)
200
F3 F = U.S. EPA ECOTOX database / U.S. EPA pesticide fate database / Miscellaneous WHO documents / FAO data, IPCS INCHEM data (US EPA Databases Related to Pesticide Risk Assessment ) 3 = Unverified data of known source
Rat NOAEL
Low
Mammals - Long Term (Chronic) Oral NOAEL (mg kg⁻¹ bw d⁻¹)
-
-
-
Mammals - Dermal LD₅₀ (mg kg⁻¹ body weight)
> 1000
Q3 Q = Miscellaneous data from online sources 3 = Unverified data of known source
Elimination is rapid and via urine as metabolites, with approximately 50% of the dose excreted within 24 hr
F3 F = U.S. EPA ECOTOX database / U.S. EPA pesticide fate database / Miscellaneous WHO documents / FAO data, IPCS INCHEM data (US EPA Databases Related to Pesticide Risk Assessment ) 3 = Unverified data of known source
-
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
?Possibly, status not identified
XNo, known not to cause a problem
XNo, known not to cause a problem
Respiratory tract irritant
Skin irritant
Skin sensitiser
No data found
✓Yes, known to cause a problem
✓Yes, known to cause a problem
Eye irritant
Phototoxicant
✓Yes, known to cause a problem
No data found
General human health issues
May cause dermatitis High doses may cause liver injury, body weight changes, upper respiratory irritation, eye damage, somnolence, and kidney effects.
Handling issues
Property
Value and interpretation
General
Incompatible with alkalies and strong acid Auto-ignition temperature: 225 DegC When heated to decomposition it emits acrid smoke and irritating fumes Combustible - above 82 DegC explosive vapour/air mixtures may be formed
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
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Environmental fate
Warning:
