Dicrotophos (Ref: OMS 253)	Last updated: 22/08/2024
(Also known as: ENT 24482; SD 3546; carbomicron ; dicrotofos; C709)

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SUMMARY

Dicrotofos is an organophosphate insecticide. It has a high aqueous solubility, quite volatile and, based on its chemical properties, it may leach to groundwater. It is not usually persistent in soils. It is highly toxic to mammals and has a low tendency to bioaccumulate. Dicrotofos is also an acetyl cholinesterase inhibitor. It has a highly toxicity to most biodiversity including honeybees and earthworms. However, it appears to be slightly less 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: GUS: High leachability Warning: Significant data are missing	Ecotoxicity High alert: Birds acute ecotoxicity: High; Daphnia acute ecotoxicity: High; Daphnia chronic ecotoxicity: High; Bees acute contact ecotoxicity: High; Bees acute oral ecotoxicity: High	Human health High alert: Mammals acute toxicity: High; Acetyl cholinesterase inhibitor

GENERAL INFORMATION

Description	An insecticide used to control sucking and chewing pests, boring insects and mites
Example pests controlled	Aphids; Thrips; Spider mites; Fleahoppers; Sink bugs; Lygus bugs; Caterpillars; Boll weevils; Elm bark bettle
Example applications	Coffee; Cotton; Rice; Pecans; Non-food producing and ornamental trees
Efficacy & activity	-
Availability status	Current
Introduction & key dates	circa 1965, introduced

GB regulatory status

GB COPR regulatory status	Not approved
Date COPR inclusion expires	Expired
GB LERAP status	No UK approval for use as a pesticide

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status	Not approved
Dossier rapporteur/co-rapporteur	Not applicable
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	-

Chemical structure

Isomerism	Isomeric existing in the E- and Z-forms. The E-isomer is more insecticidally active than the Z-isomer.
Chemical formula	C₈H₁₆NO₅P
Canonical SMILES	CC(=CC(=O)N(C)C)OP(=O)(OC)OC
Isomeric SMILES	O=P(O/C(=C/C(=O)N(C)C)C)(OC)OC
International Chemical Identifier key (InChIKey)	VEENJGZXVHKXNB-VOTSOKGWSA-N
International Chemical Identifier (InChI)	InChI=1S/C8H16NO5P/c1-7(6-8(10)9(2)3)14-15(11,12-4)13-5/h6H,1-5H3/b7-6+
2D structure diagram/image available?	Yes

General status

Pesticide type	Insecticide, Acaricide
Substance groups	Organophosphate insecticide
Minimum active substance purity	-
Known relevant impurities	-
Substance origin	Synthetic
Mode of action	Systemic with contact and stomach action. Acetylcholinesterase (AChE) inhibitor.
CAS RN	141-66-2
EC number	205-494-3
CIPAC number	299
US EPA chemical code	035201
PubChem CID	5371560
CLP index number	015-073-00-4
Molecular mass	237.19
PIN (Preferred Identification Name)	(2E)-4-(dimethylamino)-4-oxobut-2-en-2-yl dimethyl phosphate
IUPAC name	(E)-2-dimethylcarbamoyl-1-methylvinyl dimethyl phosphate
CAS name	(1E)-3-(dimethylamino)-1-methyl-3-oxo-1-propenyl dimethyl phosphate
Other status information	Potential groundwater pollutant; Marine Pollutant
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	Leucoptera meyricki, Lygus lineolaris, Panonychus ulmi, Psylla pyricola, Bemisia tabaci, Boophilus microplus, many others
Physical state	Yellow brown liquid

Formulations

Property	Value
Example manufacturers & suppliers of products using this active now or historically	Amvac Chemical Co Shell Ciba-Geigy Kenogard
Example products using this active	Carbicron Ektafos Carbomicron Bidrin Diapadrin
Formulation and application details	Often supplied as a water soluble concentrate or ULV spray.

ENVIRONMENTAL FATE

Property		Value	Source; quality score; and other information	Interpretation
Solubility - In water at 20 °C (mg l⁻¹)		1000000	V3 V = ChemID Online Databases; Chemspider; PubChem. (ChemID ) 3 = Unverified data of known source at 25 °C	High
Solubility - In organic solvents at 20 °C (mg l⁻¹)		Miscible	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source Acetone	-
		Miscible	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source Xylene	-
		Miscible	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source Dichloromethane	-
Melting point (°C)		-	-	-
Boiling point (°C)		-	-	-
Degradation point (°C)		-	-	-
Flashpoint (°C)		-	-	-
Octanol-water partition coefficient at pH 7, 20 °C	P	3.16 X 10-01	Calculated	-
	Log P	-0.5	H4 H = The US ARS pesticide properties database. Dataset is no longer available. 4 = Verified data	Low
Fat solubility of residues	Solubility	-	-	-
	Data type	-	-	-
Density (g ml⁻¹)		1.22	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)		9.3	H4 H = The US ARS pesticide properties database. Dataset is no longer available. 4 = Verified data	Moderately volatile. If applied directly to plants or soil, drift is a concern & mitigation is advisable
Henry's law constant at 25 °C (Pa m³ mol⁻¹)		5.10 X 10-06	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)	28	M4 M = GLEAMS Model database (Groundwater Loading Effects of Agricultural Management Systems). Dataset no longer available. 4 = Verified data	Non-persistent
	DT₅₀ (lab at 20 °C)	-	-	-
	DT₅₀ (field)	-	-	-
	DT₉₀ (lab at 20 °C)	-	-	-
	DT₉₀ (field)	-	-	-
	DT₅₀ modelling endpoint	-	-	-
	Note	Best available data
Dissipation rate RL₅₀ (days) on plant matrix	Value	1.0	R3 R = Peer reviewed scientific publications 3 = Unverified data of known source	-
	Note	Cotton leaves, n=1
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	-	-	-
	Note	-
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)	-	M3 M = GLEAMS Model database (Groundwater Loading Effects of Agricultural Management Systems). Dataset no longer available. 3 = Unverified data of known source	Moderately mobile
	Koc (mL g⁻¹)	75
	Notes and range	-
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		3.08	Calculated	High leachability
SCI-GROW groundwater index (μg l⁻¹) for a 1 kg ha⁻¹ or 1 l ha⁻¹ application rate	Value	2.83 X 10-01	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)	75	Q2 Q = Miscellaneous data from online sources 2 = Unverified data of unknown source Estimated	Low potential
	CT₅₀ (days)	Not available		-

Known soil metabolites

Metabolite	Major/Minor fraction	Estimated maximum occurrence fraction	Notes
butanamide	-	-	-
N,N-dimethylacetoacetamide	Major fraction	0.20	-
2-hydroxy-N,N-dimethylacetamide	-	-	Flooded soil

Known groundwater metabolites

None

Other known metabolites

Metabolite name and reference	Aliases	Formation medium / Rate	Estimated maximum occurrence fraction
monocrotophos (Ref: ENT 27129)	-	Animal; Plants	-

ECOTOXICOLOGY

Terrestrial ecotoxicology

Property		Value	Source; quality score; and other information	Interpretation
Mammals - Acute oral LD₅₀ (mg kg⁻¹)		22	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	High
Mammals - Short term dietary NOEL	(mg kg⁻¹)	0.05	L2 L = Pesticide manuals and hard copy reference books / other sources 2 = Unverified data of unknown source Rat 2 yr	High
	(ppm diet)	1		-
Mammals - Chronic 21d NOAEL (mg kg⁻¹ bw d⁻¹)		-	-	-
Birds - Acute LD₅₀ (mg kg⁻¹)		9.63	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 Anas platyrhynchos	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)	0.036	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 Apis mellifera	High
	Oral acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)	0.068	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 Apis mellifera	High
	Unknown mode acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)	-	-	-
	Chronic	-	-	-
	Notes	[The residual time to 25% mortality (RT25) value for honeybees is 48 hrs - USEPA data]
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)	0.0003	R4 R = Peer reviewed scientific publications 4 = Verified data Megachile rotundata	High
	Mode of exposure	Contact
Other bee species (2)	Acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg insect⁻¹)	0.685	R4 R = Peer reviewed scientific publications 4 = Verified data Trigona spinipes	High
	Mode of exposure	Contact
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)		6.3	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 Oncorhynchus mykiss	Moderate
Temperate Freshwater Fish - Chronic 21 day NOEC (mg l⁻¹)		-	-	-
Tropical Freshwater Fish - Acute 96 hour LC₅₀ (mg l⁻¹)		-	-	-
Temperate Freshwater Aquatic invertebrates - Acute 48 hour EC₅₀ (mg l⁻¹)		0.013	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 Daphnia magna	High
Temperate Freshwater Aquatic invertebrates - Chronic 21 day NOEC (mg l⁻¹)		0.00099	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 Daphnia magna	High
Tropical Freshwater Aquatic invertebrates - Acute 48 hour EC₅₀ (mg l⁻¹)		> 0.014	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 Ceriodaphnia dubia LC₅₀	High
Aquatic crustaceans - Acute 96 hour LC₅₀ (mg l⁻¹)		0.077	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	High
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 (free-floating, growth) - Acute 7 day EC₅₀, biomass (mg l⁻¹)		-	-	-
Aquatic plants (rooted, growth) - Acute 14 day EC₅₀, biomass (mg l⁻¹)		-	-	-
Algae - Acute 72 hour EC₅₀, growth (mg l⁻¹)		-	-	-
Algae - Chronic 96 hour NOEC, growth (mg l⁻¹)		-	-	-
Mesocosm study data	NOEAEC mg l⁻¹	-	-	-
	NOEAEC mg l⁻¹	-	-	-
Marine bivalves		-	-	-

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)		22	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	High
Mammals - Dermal LD₅₀ (mg kg⁻¹ body weight)		110	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source Rat	-
Mammals - Inhalation LC₅₀ (mg l⁻¹)		0.09	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)		-	-	-
ARfD - Acute Reference Dose (mg kg⁻¹ bw day⁻¹)		-	-	-
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	Low risk to Europeans as no longer approved for use
	Occupational	Rapidly absorbed through the skin, PPE/PPC essential
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 A0 A = Chromosome aberration (EFSA database) 0 = No data ; 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 ; E2 E = Unspecified genotoxicity type (miscellaneous data source) 2 = Mixed/ambiguous results ?Possibly, status not identified Reproduction / development effects Acetyl cholinesterase inhibitor Neurotoxicant No data found ✓Yes, known to cause a problem No data found Respiratory tract irritant Skin irritant Skin sensitiser No data found ?Possibly, status not identified No data found Eye irritant Phototoxicant   ?Possibly, status not identified No data found
General human health issues		Toxic if ingested, inhaled or by skin contact US EPA - weak evidence to support carcinogen classification

Handling issues

Property	Value and interpretation
General	IMDG Transport Hazard Class 6.1
CLP classification 2013	Health: H300, H311 Environment: H400, H410
WHO Classification	Ib (Highly hazardous)
UN Number	UN3018
Waste disposal & packaging	-
Shelf-life, storage, stability and reactivity	-

TRANSLATIONS

Language	Name
English	dicrotophos
French	dicrotophos
German	Dicrotophos
Danish	dicrotophos
Italian	dicrotofos
Spanish	dicrotofos
Greek	dicrotophos
Polish	dikrotofos
Swedish	-
Hungarian	-
Dutch	dicrotofos
Norwegian	-

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Record last updated:	22/08/2024
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