(Also known as: diphenamide; diphenylamide; difenamide)
SUMMARY
Diphenamid is a selective herbicide for annual grasses and some broad-leaved weeds. It is moderately soluble in water and has a low volatility. It is expected to moderately persistent in soils. There are significant gaps in ecotoxicological data but diphenamid is highly toxic to aquatic invertebrates, moderately toxic to fish, and has a low avian and honeybee toxicity. The substance has a moderate oral mammalian toxicity.
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: GUS: Transition state; Drainflow: Moderately mobile
Warning: Significant data are missing
Ecotoxicity High alert: Daphnia acute ecotoxicity: High
Human health Moderate alert: Mammals acute toxicity: Moderate
GENERAL INFORMATION
Description
A herbicide used for pre-emergence control of annual grasses and some broad-leaved weeds
Selective, systemic, absorbed through roots. Inhibition of very long chain fatty acids (VLCFA, inhibition of cell division)
CAS RN
957-51-7
EC number
213-482-4
CIPAC number
372
US EPA chemical code
036601
PubChem CID
13728
CLP index number
616-007-00-2
Molecular mass
239.31
PIN (Preferred Identification Name)
N,N-dimethyl-2,2-diphenylacetamide
IUPAC name
N,N-dimethyldiphenylacetamide
CAS name
N,N-dimethyl-α-phenylbenzeneacetamide
Other status information
-
Relevant Environmental Water Quality Standards
-
Herbicide Resistance Class (HRAC MoA class)
K3
Herbicide Resistance Class (WSSA MoA class)
15
Insecticide Resistance Class (IRAC MoA class)
Not applicable
Fungicide Resistance Class (FRAC MOA class)
Not applicable
Examples of recorded resistance
-
Physical state
Colourless crystals
Formulations
Property
Value
Example manufacturers & suppliers of products using this active now or historically
Elanco
UpJohn
Example products using this active
Dymid
Enide
Formulation and application details
Supplied in a variety of formulations including wettable powders, liquid dispersions and granules
ENVIRONMENTAL FATE
Property
Value
Source; quality score; and other information
Interpretation
Solubility - In water at 20 °C (mg l⁻¹)
260
L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source
Moderate
Solubility - In organic solvents at 20 °C (mg l⁻¹)
189000
L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source
Acetone
-
50000
L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source
Xylene
-
Melting point (°C)
135
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
1.48 X 1002
Calculated
-
Log P
2.17
V3 V = ChemID Online Databases; Chemspider; PubChem. (ChemID ) 3 = Unverified data of known source
Low
Fat solubility of residues
Solubility
-
-
-
Data type
-
-
-
Density (g ml⁻¹)
1.17
L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source
-
Dissociation constant pKa) at 25 °C
-
-
-
-
Vapour pressure at 20 °C (mPa)
3.04 X 10-03
V3 V = ChemID Online Databases; Chemspider; PubChem. (ChemID ) 3 = Unverified data of known source
at 25 °C
Low volatility
Henry's law constant at 25 °C (Pa m³ mol⁻¹)
3.68 X 10-06
V3 V = ChemID Online Databases; Chemspider; PubChem. (ChemID ) 3 = Unverified data of known source
at 25 °C
Non-volatile
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)
30
M3 M = GLEAMS Model database (Groundwater Loading Effects of Agricultural Management Systems). Dataset no longer available. 3 = Unverified data of known source
Moderately 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 (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)
-
M3 M = GLEAMS Model database (Groundwater Loading Effects of Agricultural Management Systems). Dataset no longer available. 3 = Unverified data of known source
Moderately mobile
Koc (mL g⁻¹)
210
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
2.48
Calculated
Transition state
SCI-GROW groundwater index (μg l⁻¹) for a 1 kg ha⁻¹ or 1 l ha⁻¹ application rate
Value
1.35 X 10-01
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
-
-
-
Bio-concentration factor
BCF (l kg⁻¹)
54
Q2 Q = Miscellaneous data from online sources 2 = Unverified data of unknown source
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