Dicrotophos (Ref: OMS 253)	Last updated: 26/11/2019
(Also known as: ENT 24482; SD 3546; carbomicron ; dicrotofos; C709)

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SUMMARY

Dicrotofos is an organophosphate insecticide that is not approved for use in the EU. 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.

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

UK regulatory status

UK approval status	Not approved

EC Regulation 1107/2009 (repealing 91/414)

EC Directive 91/414 Status	Not approved
Dossier rapporteur/co-rapporteur	Not applicable
Date inclusion expires	Expired
EU Candidate for substitution (CfS)	Not applicable
Listed in EU database	Yes
Approved for use (✓) or known to be used (#) in the following EU-27 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

Also used in

Also used in	USA

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 group	Organophosphate
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
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 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	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	Carbicron Ektafos Carbomicron Bidrin Diapadrin
Example products using this active	Amvac Chemical Co Shell Ciba-Geigy Kenogard
UK LERAP status	No UK approval for use as a pesticide under EC Regulation 1107/2009
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 / IPCS INCHEM (ChemID; IPCS INCHEM ) 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 (click here ) 4 = Verified data	Low
Bulk 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		9.3	H4 H = The US ARS pesticide properties database (click here ) 4 = Verified data	Moderately volatile
Henry's law constant at 25 °C		5.10 X 10-06	H4 H = The US ARS pesticide properties database (click here ) 4 = Verified data	Non-volatile
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	-
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) (click here ) 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 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 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)		-	-	-

Soil adsorption and mobility

Property		Value	Source; quality score; and other information	Interpretation
Linear	Kd	-	M3 M = GLEAMS Model database (Groundwater Loading Effects of Agricultural Management Systems) (click here ) 3 = Unverified data of known source	Moderately mobile
	Koc	75
	Notes and range	-
Freundlich	Kf	-	-	-
	Kfoc	-
	1/n	-
	Notes and range	-
pH sensitivity		-

Key metabolites

Metabolite	Formation medium	Estimated maximum occurrence fraction	1107/2009 relevancy
butanamide	Soil	-	-

ECOTOXICOLOGY

Property		Value	Source; quality score; and other information	Interpretation
Bio-concentration factor	BCF (l kg⁻¹)	75	Q2 Q = Miscellaneous internet resources 2 = Unverified data of unknown source Estimated	Low potential
	CT₅₀ (days)	Not available		-
Mammals - Acute oral LD₅₀ (mg kg⁻¹)		17	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source 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 year	High
	(ppm diet)	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 (US EPA Databases Related to Pesticide Risk Assessment ) 4 = Verified data Anas platyrhynchos	High
Birds - Short term dietary (LC₅₀/LD₅₀)		-	-	-
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 (US EPA Databases Related to Pesticide Risk Assessment ) 4 = Verified data Oncorhynchus mykiss	Moderate
Fish - Chronic 21 day NOEC (mg l⁻¹)		-	-	-
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 (US EPA Databases Related to Pesticide Risk Assessment ) 3 = Unverified data of known source Daphnia magna	High
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 (US EPA Databases Related to Pesticide Risk Assessment ) 3 = Unverified data of known source Daphnia magna	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 (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 - Acute 7 day EC₅₀, biomass (mg l⁻¹)		-	-	-
Non-target plants		-	-	-
		-	-	-
Algae - Acute 72 hour EC₅₀, growth (mg l⁻¹)		-	-	-
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)	-	-	-
	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 (US EPA Databases Related to Pesticide Risk Assessment ) 4 = Verified data	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)	-	-	-
		-
	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 pollinators (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 pollinators (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
Earthworms - Acute 14 day LC₅₀ (mg kg⁻¹)		-	-	-
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	-	-	-
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)		17	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source 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
European MRLs		EU MRL pesticide database
Drinking Water Standards		-	-	-
Drinking Water MAC (μg l⁻¹)		-	-	-

Health issues

Specific human health issues		Carcinogen Genotoxic Endocrine disruptor ?Possibly, status not identified 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

Handling issues

Property	Value and interpretation
General	No information available
CLP classification 2013	Health: H300, H311 Environment: H400, H410
EC Risk Classification	T+ - Very toxic: R28 T - Toxic: R24 N - Dangerous for the environment: R50, R53
EC Safety Classification	S1/2, S28, S36/37, S45, S60, S61
WHO Classification	Ib (Highly hazardous / Highly hazardous)
UN Number	3018
Waste disposal & packaging	-

TRANSLATIONS

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

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Record last updated:	26/11/2019
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