Acephate	Last updated: 27/04/2021
(Also known as: orthene)

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SUMMARY

Acephate is an organophosphate insecticide that does not have approval for use in the EU. 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

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 group	Organophosphate
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
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
Related substances & organisms	chlorpyrifos imidacloprid

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 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
Bulk 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 (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 (click here ) 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 (click here ) 4 = Verified data	Non-persistent
	DT₅₀ (lab at 20 °C)	-	-	-
	DT₅₀ (field)	3	H4 H = The US ARS pesticide properties database (click here ) 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	CA3 CA = Medical and toxicological databases and information systems e.g. TOXNET (click here ) 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	-

Key metabolites

Metabolite	Formation medium	Estimated maximum occurrence fraction	1107/2009 relevancy
methamidophos (Ref: ENT 27396)	Soil	-	-

ECOTOXICOLOGY

Property		Value	Source; quality score; and other information	Interpretation
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		-
Mammals - Acute oral LD₅₀ (mg kg⁻¹)		945	F4 F = U.S. EPA ECOTOX database / U.S. EPA pesticide fate database / Miscellaneous WHO documents (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 (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)		-	-	-
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 (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 (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 (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)		-	-	-
Non-target plants		-	-	-
		-	-	-
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)		-	-	-
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)	-	-	-
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 pollinators (1)	Acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg insect⁻¹)	-	-	-
	Mode of exposure	-
Other pollinators (2)	Acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg insect⁻¹)	-	-	-
	Mode of exposure	-
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)		-	-	-
Other soil macro-organisms	Acute LC₅₀ (mg kg⁻¹)	-	-	-
	Chronic NOEC (mg kg⁻¹)	-	-	-
Other arthropod (1)	LR₅₀ g ha⁻¹	-	-	-
	% Effect	Harmful	Q2 Q = Miscellaneous internet resources 2 = Unverified data of unknown source Parasitoids	-
Other arthropod (2)	LR₅₀ g ha⁻¹	-	-	-
	% Effect	-	-	-
Soil micro-organisms		-	-	-
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 (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)		0.03	F5 F = U.S. EPA ECOTOX database / U.S. EPA pesticide fate database / Miscellaneous WHO documents (US EPA Databases Related to Pesticide Risk Assessment ) 5 = Verified data used for regulatory purposes JMPR 2005	-
ARfD - Acute Reference Dose (mg kg⁻¹ bw day⁻¹)		0.1	F5 F = U.S. EPA ECOTOX database / U.S. EPA pesticide fate database / Miscellaneous WHO documents (US EPA Databases Related to Pesticide Risk Assessment ) 5 = Verified data used for regulatory purposes JMPR 2005	-
AAOEL - Acute Acceptable Operator Exposure Level (mg kg⁻¹ bw day⁻¹)		-	-	-
AOEL - Acceptable Operator Exposure Level - Systemic (mg kg⁻¹ bw day⁻¹)		-	-	-
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)		-	-	-

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 Code is 6.1
CLP classification 2013	Health: H302
EC Risk Classification	Xn - Harmful: R22
EC Safety Classification	S2, S36
WHO Classification	II (Moderately hazardous)
UN Number	Active 2783, liquid products usually 3018
Waste disposal & packaging	-

TRANSLATIONS

Language	Name
English	acephate
French	acéphate
German	Acephat
Danish	acephat
Italian	acefate
Spanish	acefato
Greek	-
Polish	acefat
Swedish	-
Hungarian	acefat
Dutch	-

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Record last updated:	27/04/2021
Contact:	aeru@herts.ac.uk
Please cite as:	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