Acephate is an organophosphate insecticide that is used to control sucking and chewing pests. It is highly soluble in water and most organic solvents, and is volatile. It is not expected to leach to groundwater. Whilst it is mobile, it tends not to be persistence in soil or aquatic systems. It is moderately toxic to mammals and has a low potential for bioaccumulation. Acephate is also a recognised irritant. It is has a moderate to low toxicity to birds, honeybees, earthworms and most aquatic organisms.
Hazard 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. These hazard alerts do not take account of usage patterns or exposure, thus do not represent risk.
Environmental fate
Ecotoxicity
Human health
Environmental fate Moderate alert: Drainflow: Moderately mobile
Ecotoxicity High alert: Bees acute oral ecotoxicity: High
Human health High alert: Endocrine disrupter; Acetyl cholinesterase inhibitor; Neurotoxicant
GENERAL INFORMATION
Description
An organophosphate insecticide used normally as a foliar spray to control chewing and sucking insects
Example pests controlled
Aphids; Leaf miners; Lepidopterous larvae; Sawflies; Thrips; Ants
No UK approval for use as a plant protection agent
EC Regulation 1107/2009 (repealing 91/414)
EC Regulation 1107/2009 status
Not approved
Dossier rapporteur/co-rapporteur
Italy
Date EC 1107/2009 inclusion expires
Expired
EU Candidate for substitution (CfS)
Not applicable
Listed in EU database
Yes
Approved for use (✓) under EC 1107/2009 in the following EU Member States
ATAustria
BEBelgium
BGBulgaria
CYCyprus
CZCzech Republic
DEGermany
DKDenmark
EEEstonia
ELGreece
ESSpain
FIFinland
FRFrance
HRCroatia
HUHungary
IEIreland
ITItaly
LTLithuania
LULuxembourg
LVLatvia
MTMalta
NLNetherlands
PLPoland
PTPortugal
RORomania
SESweden
SISlovenia
SKSlovakia
Approved for use (✓) under EC 1107/2009 by Mutual Recognition of Authorisation and/or national regulations in the following EEA countries
ISIceland
NONorway
Additional information
Also used in
Australia; USA
Chemical structure
Isomerism
Acephate has a chiral centre on the phosphorus atom, leading to the possibility of enantiomers. However, these chiral forms are not commonly produced in the context of pesticide application.
Broad-spectrum, contact and ingestion systemic action. Weak acetylcholinesterase (AChE) inhibitor.
CAS RN
30560-19-1
EC number
250-241-2
CIPAC number
338
US EPA chemical code
103301
PubChem CID
1982
CLP index number
015-079-00-7
Molecular mass
183.17
PIN (Preferred Identification Name)
(E)-(O,S-dimethyl acetylphosphoramidothioate)
IUPAC name
(RS)-N-[methoxy(methylthio)phosphinoyl]acetamide
CAS name
O,S-dimethyl acetylphosphoramidothioate
Forever chemical
-
Other status information
Potential groundwater contaminant; Chemical subject to PIC regulations
Relevant Environmental Water Quality Standards
-
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
Adoxophyes orana,Aphis gossypii, Myzus persicae, Phorodon humuli, Trialeurodes vaporariorum, Lygus lineolaris, plus others
Physical state
Colourless/white solid
Commercial
Property
Value
Availability status
Current
Introduction & key dates
circa 1970, first introduced
Example manufacturers & suppliers of products using this active now or historically
Cheminova
King Tech Corp
United Phorsporus
Valent
Chevron
Example products using this active
Tornado
Ortril
Cekucefate
Sunphate
Orthene
Ortran
Acephate
Acephate 50 Fire Ant Insecticide
Formulation and application details
Usually supplied as a soluble powder or granules.
Commercial production
Acephate is manufactured through a continuous chemical process that enhances efficiency and yield. The synthesis begins by reacting O,O-dimethyl phosphoroamidothioate with dimethyl sulfate to produce methamidophos, a key intermediate. This compound is then acetylated using an acetylating agent to form acephate.
Impact on climate of production and use
Data for the amount of life cycle GHGs produced by acephate are not available in the public domain. However, whilst estimates vary, more general data suggests that between 14 and 19 kilograms of CO₂e is emitted per kilogram of insecticide produced.
ENVIRONMENTAL FATE
Property
Value
Source; quality score; and other information
Interpretation
Solubility - In water at 20 °C (mg l⁻¹)
790000
W4 W = French database provided by ARVALIS-Institut du Végétal. Dataset no longer available. 4 = Verified data
High
Solubility - In organic solvents at 20 °C (mg l⁻¹)
151000
L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source
Acetone
-
100000
L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source
Ethanol
-
35000
L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source
Ethyl acetate
-
100
L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source
Hexane
-
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
L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source
-
Degradation point (°C)
-
-
-
Flashpoint (°C)
-
-
-
Octanol-water partition coefficient at pH 7, 20 °C
P
1.41 X 10-01
Calculated
-
Log P
-0.85
R3 R = Peer reviewed scientific publications 3 = Unverified data of known source
Low
Fat solubility of residues
Solubility
-
-
-
Data type
-
-
-
Density (g ml⁻¹)
1.35
L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source
L3 L = Pesticide manuals and hard copy reference books / other sources 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)
5.15 X 10-08
H4 H = The US ARS pesticide properties database. Dataset is no longer available. 4 = Verified data
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)
3
H4 H = The US ARS pesticide properties database. Dataset is no longer available. 4 = Verified data
Non-persistent
DT₅₀ (lab at 20 °C)
-
-
-
DT₅₀ (field)
3
H4 H = The US ARS pesticide properties database. Dataset is no longer available. 4 = Verified data
Non-persistent
DT₉₀ (lab at 20 °C)
-
-
-
DT₉₀ (field)
-
-
-
DT₅₀ modelling endpoint
-
-
-
Note
Best available data
Dissipation rate RL₅₀ (days) on plant matrix
Value
4.8
R4 R = Peer reviewed scientific publications 4 = Verified data
-
Note
Published literature RL₅₀ range 0.7-8.5 days, 8 field & undercover grown crops, various matrices, n=11
Dissipation rate RL₅₀ (days) on and in plant matrix
Value
6.16
R4 R = Peer reviewed scientific publications 4 = Verified data
-
Note
Published literature RL₅₀ range 1.0-12.4 days, 13 field & undercover grown crops, various matrices, n=23
Aqueous photolysis DT₅₀ (days) at pH 7
Value
2
L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source
Moderately fast
Note
-
Aqueous hydrolysis DT₅₀ (days) at 20 °C and pH 7
Value
50
V3 V = ChemID Online Databases; Chemspider; PubChem. (ChemID ) 3 = Unverified data of known source
Moderately persistent
Note
Hydrolysis data applies for pH range 5-7
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)
1.6
R4 R = Peer reviewed scientific publications 4 = Verified data
Moderately mobile
Koc (mL g⁻¹)
302
Notes and range
Literature data: Kd range 0.54-4.98 mL g⁻¹, Koc range 24.4-545 mL g⁻¹, Soils = 19
Freundlich
Kf (mL g⁻¹)
0.21
R4 R = Peer reviewed scientific publications 4 = Verified data
Mobile
Kfoc (mL g⁻¹)
40.3
1/n
1.81
Notes and range
Literature data: Kf range 0.01-0.90 mL g⁻¹, Kfoc range 1.9-188 mL g⁻¹, 1.n range 1.43-2.08, Soils = 19
pH sensitivity
-
Fate indices
Property
Value
Source; quality score; and other information
Interpretation
GUS leaching potential index
1.14
Calculated
Low leachability
SCI-GROW groundwater index (μg l⁻¹) for a 1 kg ha⁻¹ or 1 l ha⁻¹ application rate
Value
2.54 X 10-03
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)
0.03
J4 J = Pesticide Action Network database (click here ) 4 = Verified data
L2 L = Pesticide manuals and hard copy reference books / other sources 2 = Unverified data of unknown source
Rat
High
(ppm diet)
-
-
Mammals - Chronic 21d NOAEL (mg kg⁻¹ bw d⁻¹)
-
-
-
Birds - Acute LD₅₀ (mg kg⁻¹)
350
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
Anas platyrhynchos
Moderate
Birds - Short term dietary (LC₅₀/LD₅₀)
-
-
-
Birds - Chronic 21d NOEL (mg kg⁻¹ bw d⁻¹)
-
-
-
Earthworms - Acute 14 day LC₅₀ (mg kg⁻¹)
> 22974
L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source
Low
Earthworms - Chronic NOEC, reproduction (mg kg⁻¹)
-
-
-
Soil micro-organisms
-
-
-
Collembola
Acute LC₅₀ (mg kg⁻¹)
-
-
-
Chronic NOEC (mg kg⁻¹)
-
-
-
Non-target plants
Vegetative vigour ER₅₀ (g ha⁻¹)
-
-
-
Seedling emergence ER₅₀ (g ha⁻¹)
-
-
-
Honeybees (Apis spp.)
Contact acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)
1.78
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)
> 0.23
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
[USEPA LD50 contact reported as 1.2 ug/bee, oral reported as 1.37 ug/bee]
Bumblebees (Bombus spp.)
Contact acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)
3.99
R3 R = Peer reviewed scientific publications 3 = Unverified data of known source
Bombus terrestris 72 hr
Moderate
-
Oral acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)
7.37
R3 R = Peer reviewed scientific publications 3 = Unverified data of known source
Bombus terrestris 72 hr
Moderate
Literature LD₅₀ varies 3.93-135.5 µg bee⁻¹ depending on test duration 24-72 hrs
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)
Harmful
Q2 Q = Miscellaneous data from online sources 2 = Unverified data of unknown source
Aphidius rhopalosiphi
-
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)
110
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
Oncorhynchus mykiss
Low
Temperate Freshwater Fish - Chronic 21 day NOEC (mg l⁻¹)
4.7
F2 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 ) 2 = Unverified data of unknown source
Galaxias maculatus 20 day
Moderate
Tropical Freshwater Fish - Acute 96 hour LC₅₀ (mg l⁻¹)
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
L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source
Rat
-
Mammals - Inhalation LC₅₀ (mg l⁻¹)
15.0
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)
None allocated
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
-
ARfD - Acute Reference Dose (mg kg⁻¹ bw day⁻¹)
None allocated
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
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
-
Dermal penetration studies (%)
-
-
-
Dangerous Substances Directive 76/464
List I; List II
-
-
Exposure Routes
Public
Dermal route highest risk Minimal risk of dietary exposure Small risk of exposure in food and water from metabolite methamidophos Source: US EPA
Occupational
Possible exposure via inhalation and dermal contact Source: US EPA
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
?Possibly, status not identified
A3 A = Chromosome aberration (EFSA database) 3 = Negative
;
B0 B = DNA damage/repair (EFSA database) 0 = No data
;
C0 C = Gene mutation (EFSA database) 0 = No data
;
D0 D = Genome mutation (EFSA database) 0 = No data
;
E3 E = Unspecified genotoxicity type (miscellaneous data source) 3 = Negative
✓Yes, known to cause a problem
Reproduction / development effects
Acetyl cholinesterase inhibitor
Neurotoxicant
No data found
✓Yes, known to cause a problem
✓Yes, known to cause a problem
Respiratory tract irritant
Skin irritant
Skin sensitiser
No data found
?Possibly, status not identified
No data found
Eye irritant
Phototoxicant
No data found
No data found
General human health issues
US EPA - possible human carcinogen Endocrine issues - Disruption of hormone expression in the hypothalamus
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
