Azamethiphos is an organophosphate used as an insecticide and as an antiparasitic agent for veterinary use. It is highly soluble in water, volatile and not expected to leach to groundwater. Not a great deal is known about its environmental persistence. It is moderately toxic to mammals and not expected to bioaccumulate. It is a mutagen, neurotoxicant and an acetyl cholinesterase inhibitor. Azamethiphos is highly toxic to birds and aquatic invertebrates and moderately toxic to fish.
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: Drainflow: Mobile
Warning: Significant data are missing
Ecotoxicity High alert: Birds acute ecotoxicity: High; Daphnia acute ecotoxicity: High; Bees acute oral ecotoxicity: High
Human health High alert: Genotoxic; Acetyl cholinesterase inhibitor; Neurotoxicant
GENERAL INFORMATION
Description
A residual organophoshorus insecticide for fly control. Also has some applications in fish farming.
UK non-statutory standard for protection of freshwater and saltwater aquatic life 0.02 µg l⁻¹ as annual average, 0.05 as max acceptable conc.
Herbicide Resistance Class (HRAC MoA class)
Not applicable
Herbicide Resistance Class (WSSA MoA class)
Not applicable
Insecticide Resistance Class (IRAC MoA class)
1B
Fungicide Resistance Class (FRAC MOA class)
Not applicable
Examples of recorded resistance
Musca domestica
Physical state
Colourless to grey cystalline solid
Formulations
Property
Value
Example manufacturers & suppliers of products using this active now or historically
Syngenta
Ciba-Geigy
Example products using this active
Alfacron
Snip
Zazafly
Formulation and application details
Often supplied as a wettable powders, direct use bait formulations and as bath additives
ENVIRONMENTAL FATE
Property
Value
Source; quality score; and other information
Interpretation
Solubility - In water at 20 °C (mg l⁻¹)
1100
E3 E = Manufacturers safety data sheets 3 = Unverified data of known source
High
Solubility - In organic solvents at 20 °C (mg l⁻¹)
610000
L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source
Dichloromethane
-
130000
L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source
Benzene
-
100000
L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source
Methanol
-
5800
L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source
n-Octanol
-
Melting point (°C)
89
L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source
-
Boiling point (°C)
Decomposes before boiling
Q3 Q = Miscellaneous data from online sources 3 = Unverified data of known source
-
Degradation point (°C)
-
-
-
Flashpoint (°C)
150
L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source
-
Octanol-water partition coefficient at pH 7, 20 °C
P
1.12 X 1001
Calculated
-
Log P
1.05
L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source
Low
Fat solubility of residues
Solubility
-
-
-
Data type
-
-
-
Density (g ml⁻¹)
1.6
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)
0.0049
E3 E = Manufacturers safety data sheets 3 = Unverified data of known source
Low volatility
Henry's law constant at 25 °C (Pa m³ mol⁻¹)
1.45 X 10-06
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)
0.25
L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source
Non-persistent
DT₅₀ (lab at 20 °C)
-
-
-
DT₅₀ (field)
-
-
-
DT₉₀ (lab at 20 °C)
-
-
-
DT₉₀ (field)
-
-
-
DT₅₀ modelling endpoint
-
-
-
Note
Best available data, Industry data DT₅₀ in loamy sand circa 6 hours (E3)
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
11
L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source
Non-persistent
Note
pH sensitive ranging from 33 days at pH 5 to 4.3 hrs at pH 9
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)
-
S1 S = Expert judgement 1 = Estimated data with little or no verification
Mobile
Koc (mL g⁻¹)
25
Notes and range
Estimated
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
-1.57
Calculated
Low leachability
SCI-GROW groundwater index (μg l⁻¹) for a 1 kg ha⁻¹ or 1 l ha⁻¹ application rate
Value
2.92 X 10-04
Calculated
-
Note
-
Potential for particle bound transport index
Low
Calculated
-
Potential for loss via drain flow
Mobile
Calculated
-
Photochemical oxidative DT₅₀ (hrs) as indicator of long-range air transport risk
-
-
-
Bio-concentration factor
BCF (l kg⁻¹)
1.56
Q2 Q = Miscellaneous data from online sources 2 = Unverified data of unknown source
Estimated
Low potential
CT₅₀ (days)
Not available
-
Known metabolites
None
ECOTOXICOLOGY
Terrestrial ecotoxicology
Property
Value
Source; quality score; and other information
Interpretation
Mammals - Acute oral LD₅₀ (mg kg⁻¹)
1180
L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source
Rat
Moderate
Mammals - Short term dietary NOEL
(mg kg⁻¹)
2
L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source
Rat
High
(ppm diet)
20
-
Mammals - Chronic 21d NOAEL (mg kg⁻¹ bw d⁻¹)
-
-
-
Birds - Acute LD₅₀ (mg kg⁻¹)
> 30.2
L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source
Colinus virginianus
High
Birds - Short term dietary (LC₅₀/LD₅₀)
-
-
-
Birds - Chronic 21d NOEL (mg kg⁻¹ bw d⁻¹)
-
-
-
Earthworms - Acute 14 day LC₅₀ (mg kg⁻¹)
-
-
-
Earthworms - Chronic NOEC, reproduction (mg kg⁻¹)
-
-
-
Soil micro-organisms
-
-
-
Collembola
Acute LC₅₀ (mg kg⁻¹)
-
-
-
Chronic NOEC (mg kg⁻¹)
-
-
-
Non-target plants
-
-
-
-
-
-
Honeybees (Apis spp.)
Contact acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)
10.0
R3 R = Peer reviewed scientific publications 3 = Unverified data of known source
Apis mellifera
Moderate
Oral acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)
0.1
R3 R = Peer reviewed scientific publications 3 = Unverified data of known source
Apis mellifera
High
Unknown mode acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)
-
-
-
Chronic
-
-
-
Notes
-
Bumblebees (Bombus spp.)
Contact acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)
-
-
-
-
Oral acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)
-
-
-
-
Mason bees (Osmia spp.)
Contact acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)
-
-
-
Oral acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)
-
-
-
Other bee species (1)
Acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg insect⁻¹)
-
-
-
Mode of exposure
-
Other bee species (2)
Acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg insect⁻¹)
-
-
-
Mode of exposure
-
Beneficial insects (Ladybirds)
-
-
-
Beneficial insects (Lacewings)
-
-
-
Beneficial insects (Parasitic wasps)
-
-
-
Beneficial insects (Predatory mites)
-
-
-
Beneficial insects (Ground beetles)
-
-
-
Aquatic ecotoxicology
Property
Value
Source; quality score; and other information
Interpretation
Temperate Freshwater Fish - Acute 96 hour LC₅₀ (mg l⁻¹)
> 0.115
L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source
Oncorhynchus mykiss
Moderate
Temperate Freshwater Fish - Chronic 21 day NOEC (mg l⁻¹)
-
-
-
Tropical Freshwater Fish - Acute 96 hour LC₅₀ (mg l⁻¹)
L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source
Rat
Moderate
Mammals - Dermal LD₅₀ (mg kg⁻¹ body weight)
2150
L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source
Rat
-
Mammals - Inhalation LC₅₀ (mg l⁻¹)
> 0.56
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)
0.025
A5 A = EU regulatory and evaluation data as published by EC, EFSA (RAR, DAR & Conclusion dossiers), EMA (e.g. EU Annex III PIC DGD) (EU - Pesticides database; EFSA Scientific Publications ) 5 = Verified data used for regulatory purposes
In rats azamethiphos is excreted via faeces, urine & in expelled air. In fish adsorption after topical application is slow and low. Excretion is rapid in all species.
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:
