Diphacinone is an anticoagulant rodenticide. It has a low aqueous solubility and a low volatility. It is not expected to be persistent in soils but may be in water systems depending on local conditions. Based on its physico-chemical properties, diphacinone is not expected to leach to groundwater. Ecotoxicological data is limited but diphacinone is moderately toxic to fish but less so to birds. This substance has a high mammalian oral toxicity and is an eye irritant.
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 High alert: Persistent; Potential for particle bound transport: High
Example manufacturers & suppliers of products using this active now or historically
Velsicol
Bell laboratories
Example products using this active
Ratindan
Diphacine
Ditrac
Gold crest
Kill-Ko
Ramik
Formulation and application details
Available in a wide variety of formulations including meal, pellet, wax block, liquid bait and concentrate formulations.
ENVIRONMENTAL FATE
Property
Value
Source; quality score; and other information
Interpretation
Solubility - In water at 20 °C (mg l⁻¹)
0.3
C4 C = AGRITOX dataset. Dataset is no longer available. 4 = Verified data
Low
Solubility - In organic solvents at 20 °C (mg l⁻¹)
22900
C4 C = AGRITOX dataset. Dataset is no longer available. 4 = Verified data
Acetone
-
16800
C4 C = AGRITOX dataset. Dataset is no longer available. 4 = Verified data
Ethanol
-
1224
C4 C = AGRITOX dataset. Dataset is no longer available. 4 = Verified data
Heptane
-
43000
C4 C = AGRITOX dataset. Dataset is no longer available. 4 = Verified data
Xylene
-
Melting point (°C)
146
L3 L = Pesticide manuals and hard copy reference books / other 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
7.08 X 1004
Calculated
-
Log P
4.85
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)
1.28
L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source
-
Dissociation constant pKa) at 25 °C
Not applicable
L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source
-
Acidic
Vapour pressure at 20 °C (mPa)
1.37 X 10-05
L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source
Low volatility
Henry's law constant at 25 °C (Pa m³ mol⁻¹)
1.55 X 10-05
L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source
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)
5
S1 S = Expert judgement 1 = Estimated data with little or no verification
Non-persistent
DT₅₀ (lab at 20 °C)
-
-
-
DT₅₀ (field)
102
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
Persistent
DT₉₀ (lab at 20 °C)
-
-
-
DT₉₀ (field)
-
-
-
DT₅₀ modelling endpoint
-
-
-
Note
Best available data - literature variable DT₅₀ 1-150 days
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
Stable
C4 C = AGRITOX dataset. Dataset is no longer available. 4 = Verified data
Stable
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)
-
S3 S = Expert judgement 3 = Unverified data of known source
Slightly mobile
Koc (mL g⁻¹)
2255
Notes and range
Other data source: 5477 mL g⁻¹ (US3)
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
1.30
Calculated
Low leachability
SCI-GROW groundwater index (μg l⁻¹) for a 1 kg ha⁻¹ or 1 l ha⁻¹ application rate
Value
3.11 X 10-02
Calculated
-
Note
-
Potential for particle bound transport index
High
Calculated
-
Potential for loss via drain flow
Slightly 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
Environmental fate
Ecotoxicity
