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Fenoprop
Last updated: 16/01/2023
(Also known as: silvex; 2,4,5-TP)
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: Slightly mobile; Potential for particle bound transport: Medium
Warning:
Significant data are missing
Ecotoxicity
Moderate alert:
Fish acute ecotoxicity: Moderate
Human health
Moderate alert:
Mammals acute toxicity: Moderate; Possible Carcinogen
GENERAL INFORMATION
Description
An obsolete phenoxypropionic herbicide and auxin plant growth regulator for control of woody plants and broad-leaved weeds on land and in aquatic situations
Example pests controlled
Black medic; Chickweed; Clover: Henbit; Spurges; Yarrow; Arrowhead; Pickelweed; Bladderwort; Water milfoil
Example applications
Paddy fields; Sugarcane; Orchards; Established turf; Cereals including barley, oats
Efficacy & activity
-
Availability status
Considered obsolete but may be available in some countries
Introduction & key dates
1945, first reported
UK regulatory status
UK COPR regulatory status
Not approved
Date COPR inclusion expires
Expired
UK LERAP status
No UK approval for use
EC Regulation 1107/2009 (repealing 91/414)
EC Regulation 1107/2009 status
Not approved
Dossier rapporteur/co-rapporteur
-
Date EC 1107/2009 inclusion expires
Expired
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
                 
Additional information
Also used in
-
Chemical structure
Isomerism
A chiral molecule existing in the R- and S-forms. Substance is racemic.
Chemical formula
C₉H₇Cl₃O₃
Canonical SMILES
CC(C(=O)O)OC1=CC(=C(C=C1Cl)Cl)Cl
Isomeric SMILES
-
International Chemical Identifier key (InChIKey)
ZLSWBLPERHFHIS-UHFFFAOYSA-N
International Chemical Identifier (InChI)
InChI=1S/C9H7Cl3O3/c1-4(9(13)14)15-8-3-6(11)5(10)2-7(8)12/h2-4H,1H3,(H,13,14)
2D structure diagram/image available?
Yes
Cambridge Crystallographic Data Centre diagrams
Common Name Relationship Link
fenoprop -
General status
Pesticide type
Herbicide, Plant Growth Regulator
Substance groups
Phenoxipropionic acid
Minimum active substance purity
-
Known relevant impurities
-
Substance origin
Synthetic
Mode of action
Synthetic auxin affecting nucleic acid biosynthesis and cell elongation
CAS RN
93-72-1
EC number
202-271-2
CIPAC number
118
US EPA chemical code
082501
PubChem CID
7158
CLP index number
607-047-00-1
Molecular mass
269.51
PIN (Preferred Identification Name)
rac-(2R)-2-(2,4,5-trichlorophenoxy)propanoic acid
IUPAC name
(RS)-2-(2,4,5-trichlorophenoxy)propionic acid
CAS name
2-(2,4,5-trichlorophenoxy)propanoic acid
Other status information
-
Relevant Environmental Water Quality Standards
-
Herbicide Resistance Classification (HRAC)
O
Herbicide Resistance Classification (WSSA)
4
Insecticide Resistance Classification (IRAC)
Not applicable
Fungicide Resistance Classification (FRAC)
Not applicable
Examples of recorded resistance
-
Physical state
White powder
Related substances & organisms
Formulations
Property
Value
Example manufacturers & suppliers of products using this active now or historically
  • Dow Chemical Co.
  • AmChem
  • Rhone-Poulenc
  • Vertac
Example products using this active
  • Fruitone T
  • Kuron
  • Silvex
  • Silvi-Rhap
Formulation and application details
Usually supplied as an emulsifiable concentrate
ENVIRONMENTAL FATE
Property
Value
Source; quality score; and other information
Interpretation
Solubility - In water at 20 °C (mg l⁻¹)
140
H4 H = The US ARS pesticide properties database. Dataset is no longer available.
4 = Verified data
 Moderate
Solubility - In organic solvents at 20 °C (mg l⁻¹)
- - -
Melting point (°C)
180
Q3 Q = Miscellaneous data from online sources
3 = Unverified data of known source
 -
Boiling point (°C)
- - -
Degradation point (°C)
- - -
Flashpoint (°C)
- - -
Octanol-water partition coefficient at pH 7, 20 °C
P
6.31 X 1003 Calculated -
Log P
3.8
V3 V = ChemID Online Databases; Chemspider; PubChem. (ChemID )
3 = Unverified data of known source
 High
Fat solubility of residues
Solubility
- - -
Data type
- - -
Density (g ml⁻¹)
1.21
Q3 Q = Miscellaneous data from online sources
3 = Unverified data of known source
 -
Dissociation constant pKa) at 25 °C
2.84
V3 V = ChemID Online Databases; Chemspider; PubChem. (ChemID )
3 = Unverified data of known source
 -
Strong acid
Vapour pressure at 20 °C (mPa)
0.1
H4 H = The US ARS pesticide properties database. Dataset is no longer available.
4 = Verified data
 Low volatility
Henry's law constant at 25 °C (Pa m³ mol⁻¹)
1.93 X 10-04
H4 H = The US ARS pesticide properties database. Dataset is no longer available.
4 = Verified data
 Non-volatile
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)
14
W4 W = French database provided by ARVALIS-Institut du Végétal. Dataset no longer available.
4 = Verified data
 Non-persistent
DT₅₀ (lab at 20 °C)
- - -
DT₅₀ (field)
- - -
DT₉₀ (lab at 20 °C)
- - -
DT₉₀ (field)
- - -
DT₅₀ modelling endpoint
- - -
Note
Best available data
Dissipation rate RL₅₀ on plant matrix
Value
- - -
Note
-
Dissipation rate RL₅₀ on and in plant matrix
Value
4.5
R3 R = Peer reviewed scientific publications
3 = Unverified data of known source
 -
Note
Kentucky bluegrass, n=1
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)
- - -
Soil adsorption and mobility
Property
Value
Source; quality score; and other information
Interpretation
Linear
Kd
-
H3 H = The US ARS pesticide properties database. Dataset is no longer available.
3 = Unverified data of known source
 Slightly mobile
Koc
2600
Notes and range
-
Freundlich
Kf
- - -
Kfoc
-
1/n
-
Notes and range
-
pH sensitivity
-
Fate indices
Property
Value
Source; quality score; and other information
Interpretation
GUS leaching potential index
0.67 Calculated Low leachability
SCI-GROW groundwater index (μg l⁻¹) for a 1 kg ha⁻¹ or 1 l ha⁻¹ application rate
Value
1.12 X 10-02 Calculated -
Note
-
Potential for particle bound transport index
Medium Calculated -
Potential for loss via drain flow
Slightly mobile Calculated -
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)
650
V3 V = ChemID Online Databases; Chemspider; PubChem. (ChemID )
3 = Unverified data of known source
Rat		 Moderate
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)
> 3031
F4 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 )
4 = Verified data
Colinus virginianus		 Low
Birds - Short term dietary (LC₅₀/LD₅₀)
- - -
Birds - Chronic 21d NOEL (mg kg⁻¹ bw d⁻¹)
- - -
Earthworms - Acute 14 day LC₅₀ (mg kg⁻¹)
- - -
Earthworms - Chronic NOEC, reproduction (mg kg⁻¹)
- - -
Soil micro-organisms
- - -
Collembola
Acute LC₅₀ (mg kg⁻¹)
- - -
Chronic NOEC (mg kg⁻¹)
- - -
Non-target plants
- - -
- - -
Honeybees (Apis 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)
- - -
Unknown mode acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)
- - -
Chronic
- - -
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)
- - -
Aquatic ecotoxicology
Property
Value
Source; quality score; and other information
Interpretation
Fish - Acute 96 hour LC₅₀ (mg l⁻¹)
> 14.8
F4 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 )
4 = Verified data
Oncorhynchus mykiss		 Moderate
Fish - Chronic 21 day NOEC (mg l⁻¹)
- - -
Aquatic invertebrates - Acute 48 hour EC₅₀ (mg l⁻¹)
> 140
F4 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 )
4 = Verified data
Daphnia magna		 Low
Aquatic invertebrates - Chronic 21 day NOEC (mg l⁻¹)
- - -
Aquatic crustaceans - Acute 96 hour LC₅₀ (mg l⁻¹)
> 27.9
F4 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 )
4 = Verified data
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)
- - -
Sediment dwelling organisms - Chronic 28 day NOEC, sediment (mg kg⁻¹)
- - -
Aquatic plants - Acute 7 day EC₅₀, biomass (mg l⁻¹)
- - -
Algae - Acute 72 hour EC₅₀, growth (mg l⁻¹)
- - -
Algae - Chronic 96 hour NOEC, growth (mg l⁻¹)
- - -
Mesocosm study data
NOEAEC mg l⁻¹
- - -
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)
650
V3 V = ChemID Online Databases; Chemspider; PubChem. (ChemID )
3 = Unverified data of known source
Rat		 Moderate
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)
0.005
L3 L = Pesticide manuals and hard copy reference books / other sources
3 = Unverified data of known source
 -
ARfD - Acute Reference Dose (mg kg⁻¹ bw day⁻¹)
- - -
AAOEL - Acute Acceptable Operator Exposure Level (mg kg⁻¹ bw day⁻¹)
- - -
AOEL - Acceptable Operator Exposure Level - Systemic (mg kg⁻¹ bw day⁻¹)
- - -
Dermal penetration studies (%)
- - -
Dangerous Substances Directive 76/464
- - -
Exposure Routes
Public
-
Occupational
-
MRLs
European
EU MRL pesticide database 
Great Britain
GB MRL Register 
Notes
-
Drinking Water Standards
Non-statutory WHO drinking water guideline 0.009 mg l⁻¹
B5 B = UK CRD and ACP Evaluation Documents / and other DEFRA (UK) documents; Also Chemicals Regulation Division, Health and Safety Executive (HSE), UK (click here )
5 = Verified data used for regulatory purposes
UK EA QS database 2018		 -
Drinking Water MAC (μg l⁻¹)
- - -
Mammalian dose elimination route and rate
- - -
Health issues
Specific human health issues
Carcinogen
Genotoxic
Endocrine disruptor
?Possibly, status not identified
A3 A = Chromosome aberration (EFSA database)
3 = Negative
;
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
;
E0 E = Unspecified genotoxicity type (miscellaneous data source)
0 = No data
 No data found
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
 No data found
Eye irritant Phototoxicant  
✓Yes, known to cause a problem
 No data found  
General human health issues
Harmful if swallowed
Handling issues
Property
Value and interpretation
General
No information available
CLP classification 2013
Health: H302, H315
Environment: H400, H410
WHO Classification
III (Slightly hazardous)
UN Number
-
Waste disposal & packaging
-
TRANSLATIONS
Language
Name
English
fenoprop
French
fenoprop
German
Fenoprop
Danish
fenoprop
Italian
fenoprop
Spanish
fenoprop
Greek
fenoprop
Polish
fenoprop
Swedish
-
Hungarian
-
Dutch
fenoprop
Record last updated: 16/01/2023
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