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Acephate
(Also known as: orthene)
SUMMARY
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.
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: Moderately mobile
Ecotoxicity
High alert:
Bees acute oral ecotoxicity: High
Human health
High alert:
Endocrine distrupter; 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
Example applications
Fruit; Vegetables; Potatoes; Sugarbeet; Vines; Rice; Hops; Ornamentals; Greenhouse crops including peppers, cucumbers
Efficacy & activity
-
Availability status
Current
Introduction & key dates
circa 1970
UK regulatory status
UK COPR regulatory status
Not approved
Date COPR inclusion expires
Expired
UK LERAP status
No UK approval for use
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
Chiral, existing in the S- and R-forms
Chemical formula
C₄H₁₀NO₃PS
Canonical SMILES
CC(=O)NP(=O)(OC)SC
Isomeric SMILES
No data
International Chemical Identifier key (InChIKey)
YASYVMFAVPKPKE-UHFFFAOYSA-N
International Chemical Identifier (InChI)
InChI=1S/C4H10NO3PS/c1-4(6)5-9(7,8-2)10-3/h1-3H3,(H,5,6,7)
2D structure diagram/image available?
Yes
Cambridge Crystallographic Data Centre diagrams
Common Name Relationship Link
acephate -
General status
Pesticide type
Insecticide
Substance groups
Organophosphate insecticide; Phosphoramidothioate insecticide
Minimum active substance purity
-
Known relevant impurities
-
Substance origin
Synthetic
Mode of action
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
Other status information
Potential groundwater contaminant; Chemical subject to PIC regulations
Relevant Environmental Water Quality Standards
-
Herbicide Resistance Classification (HRAC)
Not applicable
Herbicide Resistance Classification (WSSA)
Not applicable
Insecticide Resistance Classification (IRAC)
1B
Fungicide Resistance Classification (FRAC)
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
Formulations
Property
Value
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.
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
 -
Dissociation constant pKa) at 25 °C
8.35
F4 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 )
4 = Verified data
 -
Weak acid
Vapour pressure at 20 °C (mPa)
0.226
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)
5.15 X 10-08
H4 H = The US ARS pesticide properties database. Dataset is no longer available.
4 = Verified data
 Non-volatile
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 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 on and in plant matrix
Value
5.8
R4 R = Peer reviewed scientific publications
4 = Verified data
 -
Note
Published literature RL₅₀ range 1.0-12.4 days, 12 field & undercover grown crops, various matrices, n=19
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)
- - -
Soil adsorption and mobility
Property
Value
Source; quality score; and other information
Interpretation
Linear
Kd
1.6
R4 R = Peer reviewed scientific publications
4 = Verified data
 Moderately mobile
Koc
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
0.21
R4 R = Peer reviewed scientific publications
4 = Verified data
 Mobile
Kfoc
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 -
Bio-concentration factor
BCF (l kg⁻¹)
0.03
J4 J = Pesticide Action Network database (click here )
4 = Verified data
 Low potential
CT₅₀ (days)
Not available -
Known soil metabolites
Metabolite
Major/Minor fraction
Estimated maximum occurrence fraction
Notes
methamidophos (Ref: ENT 27396)
- - -
Known groundwater metabolites

None

Other known metabolites

None
ECOTOXICOLOGY
Terrestrial ecotoxicology
Property
Value
Source; quality score; and other information
Interpretation
Mammals - Acute oral LD₅₀ (mg kg⁻¹)
945
F4 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 )
4 = Verified data
Rat		 Moderate
Mammals - Short term dietary NOEL
(mg kg⁻¹)
0.25
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
- - -
- - -
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
- - -
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
Parasitic wasp		 -
Beneficial insects (Predatory mites)
- - -
Beneficial insects (Ground beetles)
- - -
Aquatic ecotoxicology
Property
Value
Source; quality score; and other information
Interpretation
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
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
Aquatic invertebrates - Acute 48 hour EC₅₀ (mg l⁻¹)
67.2
L3 L = Pesticide manuals and hard copy reference books / other sources
3 = Unverified data of known source
Daphnia magna		 Moderate
Aquatic invertebrates - Chronic 21 day NOEC (mg l⁻¹)
43
L3 L = Pesticide manuals and hard copy reference books / other sources
3 = Unverified data of known source
Daphnia magna		 Low
Aquatic crustaceans - Acute 96 hour LC₅₀ (mg l⁻¹)
7.3
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
Americamysis bahia		 Moderate
Sediment dwelling organisms - Acute 96 hour LC₅₀ (mg l⁻¹)
- - -
Sediment dwelling organisms - Chronic 28 day NOEC, static, water (mg l⁻¹)
- - -
Sediment dwelling organisms - Chronic 28 day NOEC, sediment (mg kg⁻¹)
- - -
Aquatic plants - Acute 7 day EC₅₀, biomass (mg l⁻¹)
- - -
Algae - Acute 72 hour EC₅₀, growth (mg l⁻¹)
980
L2 L = Pesticide manuals and hard copy reference books / other sources
2 = Unverified data of unknown source
Unknown species		 Low
Algae - Chronic 96 hour NOEC, growth (mg l⁻¹)
- - -
Mesocosm study data
NOEAEC mg l⁻¹
- - -
NOEAEC mg l⁻¹
- - -
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)
945
F4 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 )
4 = Verified data
Rat		 Moderate
Mammals - Dermal LD₅₀ (mg kg⁻¹ body weight)
10000
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
 -
AAOEL - Acute Acceptable Operator Exposure Level (mg kg⁻¹ bw day⁻¹)
- - -
AOEL - Acceptable Operator Exposure Level - Systemic (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
 -
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
USEPA - possible human carcinogen
Endocrine issues - Disruption of hormone expression in the hypothalamus
Handling issues
Property
Value and interpretation
General
IMDG Transport Hazard Class 6.1
CLP classification 2013
Health: H302
WHO Classification
II (Moderately hazardous)
UN Number
UN2811
Waste disposal & packaging
Packaging Group III (minor danger)
Shelf-life, storage, stability and reactivity
-
TRANSLATIONS
Language
Name
English
acephate
French
acéphate
German
Acephat
Danish
acephat
Italian
acefate
Spanish
acefato
Greek
-
Polish
acefat
Swedish
-
Hungarian
acefat
Dutch
-
Norwegian
-
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