Acifluorfen is a post-emergence herbicide, usually used as the sodium salt. It is highly soluble in water, with a low vapour pressure and may be moderately persistent in soils and water depending upon conditions. Based on its chemical properties it has a high potential for leaching to groundwater. It has a low to moderate toxicity to most biodiversity. It is not highly toxic to human but is known to be a skin and eye irritant.
Hazard alerts
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 High alert: GUS: High leachability
Human health High alert: Mammals chronic toxicity: High
GENERAL INFORMATION
Description
Post emergence herbicide, usually used as the sodium salt; particularly effective against broadleaved weeds and grasses. Also a pesticide transformation product.
Example manufacturers & suppliers of products using this active now or historically
Rohm & Haas
United Phosphorus
Example products using this active
Blazer
Tackle
Formulation and application details
Formulations include liquid, ready-to-use, and soluble concentrates.
Commercial production
Acifluorfen is commercially produced through the synthesis of diphenyl ether derivatives, specifically by coupling a substituted nitrophenol with a halogenated benzoic acid derivative. The process typically involves nitration, etherification, and halogenation steps under controlled conditions to form the active herbicidal compound. These reactions require organic solvents, catalysts, and purification stages to ensure product stability and efficacy.
Impact on climate of production and use
There are no direct GHG emission data publicly reported for the commercial production of acifluorfen, but is likely to be in the range of 30–60 kg CO₂e per kg of active ingredient, based on life cycle assessments of similar diphenyl ether herbicides. This figure is likely to include packaging, transport and application.
ENVIRONMENTAL FATE
Property
Value
Source; quality score; and other information
Interpretation
Solubility - In water at 20 °C at pH 7 (mg l⁻¹)
250000
G3 G = Extension Toxicology network database EXTOXNET. Available online but no longer updated. (click here ) 3 = Unverified data of known source
High
Solubility - In organic solvents at 20 °C (mg l⁻¹)
50000
Q2 Q = Miscellaneous data from online sources 2 = Unverified data of unknown source
Acetone
-
1000
Q2 Q = Miscellaneous data from online sources 2 = Unverified data of unknown source
n-Hexane
-
Melting point (°C)
155
G3 G = Extension Toxicology network database EXTOXNET. Available online but no longer updated. (click here ) 3 = Unverified data of known source
-
Boiling point (°C)
-
-
-
Degradation point (°C)
235
L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source
-
Flashpoint (°C)
-
-
-
Octanol-water partition coefficient at pH 7, 20 °C
P
1.51 X 1001
Calculated
-
Log P
1.18
G3 G = Extension Toxicology network database EXTOXNET. Available online but no longer updated. (click here ) 3 = Unverified data of known source
Low
Fat solubility of residues
Solubility
-
-
-
Data type
-
-
-
Density (g ml⁻¹)
-
-
-
Dissociation constant pKa) at 25 °C
3.86
R3 R = Peer reviewed scientific publications 3 = Unverified data of known source
-
Weak acid
Vapour pressure at 20 °C (mPa)
0.133
G3 G = Extension Toxicology network database EXTOXNET. Available online but no longer updated. (click here ) 3 = Unverified data of known source
Low volatility. If applied directly to plants, drift is a concern & mitigation is advisable
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)
54
G3 G = Extension Toxicology network database EXTOXNET. Available online but no longer updated. (click here ) 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
Other sources: DT₅₀ 108 (silt loam) - 200 (clay) days (R3)
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
4
G3 G = Extension Toxicology network database EXTOXNET. Available online but no longer updated. (click here ) 3 = Unverified data of known source
Moderately fast
Note
-
Aqueous hydrolysis DT₅₀ (days) at 20 °C and pH 7
Value
Stable
G3 G = Extension Toxicology network database EXTOXNET. Available online but no longer updated. (click here ) 3 = Unverified data of known source
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)
-
G2 G = Extension Toxicology network database EXTOXNET. Available online but no longer updated. (click here ) 2 = Unverified data of unknown source
Moderately mobile
Koc (mL g⁻¹)
113
Notes and range
-
Freundlich
Kf (mL g⁻¹)
13.2
R4 R = Peer reviewed scientific publications 4 = Verified data
Moderately mobile
Kfoc (mL g⁻¹)
160
1/n
1.05
Notes and range
Literature data: Kf range 0.57-43.11 mL g⁻¹, Kfoc range 65.3-291.3 mL.g, 1/n range 0.952-1.190, Soils=5
pH sensitivity
-
Fate indices
Property
Value
Source; quality score; and other information
Interpretation
GUS leaching potential index
3.11
Calculated
High leachability
SCI-GROW groundwater index (μg l⁻¹) for a 1 kg ha⁻¹ or 1 l ha⁻¹ application rate
Value
3.53 X 10-01
Calculated
-
Note
-
Potential for particle bound transport index
Medium
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)
Low risk
Q3 Q = Miscellaneous data from online sources 3 = Unverified data of known source
Based on LogP < 3
Low risk
CT₅₀ (days)
-
-
Known metabolites
None
ECOTOXICOLOGY
Terrestrial ecotoxicology
Property
Value
Source; quality score; and other information
Interpretation
Mammals - Acute oral LD₅₀ (mg kg⁻¹)
1370
G3 G = Extension Toxicology network database EXTOXNET. Available online but no longer updated. (click here ) 3 = Unverified data of known source
Rat
Moderate
Mammals - Short Term Oral NOAEL (mg kg⁻¹ bw d⁻¹)
-
-
-
Mammals - Long Term (Chronic) Oral NOAEL (mg kg⁻¹ bw d⁻¹)
0.63
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
Dog 1-yr
High
Birds - Acute LD₅₀ (mg kg⁻¹)
> 2821
G3 G = Extension Toxicology network database EXTOXNET. Available online but no longer updated. (click here ) 3 = Unverified data of known source
Anas platyrhynchos
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 dw soil)
> 1800
L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source
Regulatory Threshold Levels (RTLs) used to calculate Total Applied Toxicity (TAT)
Species group
RTL
Notes
Mammals
0.126
Worst case of acute and chronic mammals
Birds
282.1
Worst case of acute and chronic birds
Soil organisms
360
Worst case of acute and chronic earthworms
Terrestrial plants
No data
No data for non-target plants vegetative vigour and seedling emergence
Pollinators
2
Worst case of contact and oral honeybees
Arthropods
No data
No data for parasitic wasps and predatory mites
Fish
0.54
Worst case of temperate acute and chronic fish
Aquatic invertebrates
0.28
Worst case of 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)
High (class III)
-
-
Mammals - Acute oral LD₅₀ (mg kg⁻¹)
1370
G3 G = Extension Toxicology network database EXTOXNET. Available online but no longer updated. (click here ) 3 = Unverified data of known source
Rat
Moderate
Mammals - Short Term Oral NOAEL (mg kg⁻¹ bw d⁻¹)
-
-
-
Mammals - Long Term (Chronic) Oral NOAEL (mg kg⁻¹ bw d⁻¹)
0.63
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
Dog 1-yr
High
Mammals - Dermal LD₅₀ (mg kg⁻¹ body weight)
> 2000
G3 G = Extension Toxicology network database EXTOXNET. Available online but no longer updated. (click here ) 3 = Unverified data of known source
Rabbit
-
Mammals - Inhalation LC₅₀ (mg l⁻¹)
6.9
G3 G = Extension Toxicology network database EXTOXNET. Available online but no longer updated. (click here ) 3 = Unverified data of known 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
Environmental fate
Warning:
Ecotoxicity
