(Also known as: mefenpyr-diethyl; AE F107892; AEF 107892)
SUMMARY
Mefenpyr diethyl is a herbicide safener with no herbicidal activity. It has a low aqueous solubility, is relatively volatile and a low potential for groundwater leaching. It is non-persistent in soil and moderately persistent in aquatic systems. it is not highly toxic to mammals and no serious human health issues have been reported although it is an irritant. It is moderately toxic to birds, earthworms and most aquatic organisms. It is not toxic to honeybees.
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
Q3 Q = Miscellaneous data from online sources 3 = Unverified data of known source
Slow
Water phase only DT₅₀ (days)
80
Q3 Q = Miscellaneous data from online sources 3 = Unverified data of known source
Stable
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)
-
C3 C = AGRITOX dataset. Dataset is no longer available. 3 = Unverified data of known source
Slightly mobile
Koc (mL g⁻¹)
634
Notes and range
Best available data
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
1.49
Calculated
Low leachability
SCI-GROW groundwater index (μg l⁻¹) for a 1 kg ha⁻¹ or 1 l ha⁻¹ application rate
Value
3.23 X 10-02
Calculated
-
Note
-
Potential for particle bound transport index
Low
Calculated
-
Potential for loss via drain flow
Slightly mobile
Calculated
-
Photochemical oxidative DT₅₀ (hrs) as indicator of long-range air transport risk
L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source
Rat
-
Other Mammal toxicity endpoints
-
-
-
ADI - Acceptable Daily Intake (mg kg⁻¹ bw day⁻¹)
0.1
B4 B = UK CRD and ACP Evaluation Documents / and other DEFRA (UK) documents; Also Chemicals Regulation Division, Health and Safety Executive (HSE), UK (click here ) 4 = Verified data
B4 B = UK CRD and ACP Evaluation Documents / and other DEFRA (UK) documents; Also Chemicals Regulation Division, Health and Safety Executive (HSE), UK (click here ) 4 = Verified data
UK ACP 1997
-
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
-
-
-
Drinking Water MAC (μg l⁻¹)
-
-
-
Mammalian dose elimination route and rate
-
-
-
Health issues
Specific human health issues
Carcinogen
Genotoxic
Endocrine disruptor
XNo, known not to cause a problem
A3 A = Chromosome aberration (EFSA database) 3 = Negative
;
B3 B = DNA damage/repair (EFSA database) 3 = Negative
;
C3 C = Gene mutation (EFSA database) 3 = Negative
;
D0 D = Genome mutation (EFSA database) 0 = No data
;
E3 E = Unspecified genotoxicity type (miscellaneous data source) 3 = Negative
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