Naproanilide is a rice herbicide. Itself it has no herbicidal activity however its major metabolite 2-(2-naphthoxy)propionic acid does. It is only slightly toxic. Photodegradation appears to be the main degradation pathway in paddy fields. Little is known about the toxicity of this substance to wildlife.
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
Warning: Significant data are missing
Human health Moderate alert: Reproduction/development effects
Warning: Significant data are missing
GENERAL INFORMATION
Description
A selective herbicide used for the control of weeds in rice paddy fields.
Example pests controlled
Broad-leaved weeds; Annual and perennial Cyperaceous weeds
Example applications
Rice
Efficacy & activity
-
Availability status
-
Introduction & key dates
circa 1981, introduced
UK regulatory status
UK COPR regulatory status
Not approved
Date COPR inclusion expires
Not applicable
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
Not applicable
Date EC 1107/2009 inclusion expires
Not applicable
EU Candidate for substitution (CfS)
Not applicable
Listed in EU database
No
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
Naproanilide is a chiral molecule and the technical material is an isomeric mixture of the S- and R-isomeric forms. The R-form exhibits the strongest herbicidal activity and is around 8x more effective than the S-form.
Example manufacturers & suppliers of products using this active now or historically
United Phosphorus
AgriGuard
Example products using this active
Devrinol
Jouster
Naprop
Formulation and application details
Often supplied as a soluble concentrate that is mixed with water and used as a spray
ENVIRONMENTAL FATE
Property
Value
Source; quality score; and other information
Interpretation
Solubility - In water at 20 °C (mg l⁻¹)
0.75
Q3 Q = Miscellaneous data from online sources 3 = Unverified data of known source
at 27 °C
Low
Solubility - In organic solvents at 20 °C (mg l⁻¹)
171000
E3 E = Manufacturers safety data sheets 3 = Unverified data of known source
Acetone
-
42000
E3 E = Manufacturers safety data sheets 3 = Unverified data of known source
Toluene
-
17000
E3 E = Manufacturers safety data sheets 3 = Unverified data of known source
Ethanol
-
Melting point (°C)
128
V3 V = ChemID Online Databases; Chemspider; PubChem. (ChemID ) 3 = Unverified data of known source
-
Boiling point (°C)
-
-
-
Degradation point (°C)
-
-
-
Flashpoint (°C)
-
-
-
Octanol-water partition coefficient at pH 7, 20 °C
P
2.00 X 1003
Calculated
-
Log P
3.3
Q3 Q = Miscellaneous data from online sources 3 = Unverified data of known source
High
Fat solubility of residues
Solubility
-
-
-
Data type
-
-
-
Density (g ml⁻¹)
1.256
Q3 Q = Miscellaneous data from online sources 3 = Unverified data of known source
-
Dissociation constant pKa) at 25 °C
Not applicable
Q3 Q = Miscellaneous data from online sources 3 = Unverified data of known source
-
No dissociation
Vapour pressure at 20 °C (mPa)
3.0 X 10-06
Q3 Q = Miscellaneous data from online sources 3 = Unverified data of known source
Low volatility
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)
0.1
R3 R = Peer reviewed scientific publications 3 = Unverified data of known source
Non-persistent
DT₅₀ (lab at 20 °C)
0.1
R3 R = Peer reviewed scientific publications 3 = Unverified data of known source
Non-persistent
DT₅₀ (field)
-
-
-
DT₉₀ (lab at 20 °C)
-
-
-
DT₉₀ (field)
-
-
-
DT₅₀ modelling endpoint
-
-
-
Note
Substance rapidly degrades to its major metabolite
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)
-
-
-
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)
-
Q3 Q = Miscellaneous data from online sources 3 = Unverified data of known source
Moderately mobile
Koc (mL g⁻¹)
370
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
-1.43
Calculated
Low leachability
SCI-GROW groundwater index (μg l⁻¹) for a 1 kg ha⁻¹ or 1 l ha⁻¹ application rate
Value
8.27 X 10-06
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
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