Dicofol (Ref: ENT 23648)	Last updated: 11/01/2021
(Also known as: kelthane; FW-293; decofol; DTMC)

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SUMMARY

Dicofol is an organochloride acaricide that is not approved for use in the EU. It has a low aqueous solubility, volatile and, based on its chemical properties, is unlikely to leach to groundwater. It is moderately persistent in soils but does not normally persist in water. It is moderately toxic to mammals and has a high tendency to bioaccumulate. Dicofol is also an irritant and neurotoxin. It has a moderate toxicity to most biodiversity including honeybees and earthworms.

GENERAL INFORMATION

Description	An acaricide used to control many species of phytophagous mite on a range of food and ornamental crops
Example pests controlled	Various mites including Pacific mite; two-spotted spider mite, tropical mites, tomato russet mite, citrus mite, European red mite
Example applications	Vegetables including beans, squash, peppers; Cotton; Cucumbers; Hops; Fruit including apples, pears, citrus, grapes
Efficacy & activity	-
Availability status	Current
Introduction & key dates	1956, first reported; 1957, first marketed USA

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	Spain
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

Also used in

Also used in	-

Chemical structure

Isomerism	Isomeric - the o,p'-substituted isomer is chiral and may have enantiomer-specific activity but, the stereospecific activity of o,p'-dicofol has not been reported.
Chemical formula	C₁₄H₉Cl₅O
Canonical SMILES	C1=CC(=CC=C1C(C2=CC=C(C=C2)Cl)(C(Cl)(Cl)Cl)O)Cl
Isomeric SMILES	Clc1ccc(cc1)C(O)(c2ccc(Cl)cc2)C(Cl)(Cl)Cl
International Chemical Identifier key (InChIKey)	UOAMTSKGCBMZTC-UHFFFAOYSA-N
International Chemical Identifier (InChI)	InChI=1S/C14H9Cl5O/c15-11-5-1-9(2-6-11)13(20,14(17,18)19)10-3-7-12(16)8-4-10/h1-8,20H
2D structure diagram/image available?	Yes

Cambridge Crystallographic Data Centre diagrams

Common Name	Relationship	Link
dicofol	-

General status

Pesticide type	Acaricide
Substance group	Organochlorine
Minimum active substance purity	-
Known relevant impurities	-
Substance origin	Synthetic
Mode of action	Non-systemic with contact action
CAS RN	115-32-2
EC number	204-082-0
CIPAC number	123
US EPA chemical code	10501
PubChem CID	8268
Molecular mass	370.49
PIN (Preferred Identification Name)	2,2,2-trichloro-1,1-bis(4-chlorophenyl)ethan-1-ol
IUPAC name	2,2,2-trichloro-1,1-bis(4-chlorophenyl)ethanol
CAS name	4-chloro-α-(4-chlorophenyl)-α-(trichloromethyl)benzenemethanol
Other status information	POP candidate; OSPAR pfa/soc; 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)	2A
Fungicide Resistance Classification (FRAC)	Not applicable
Examples of recorded resistance	Panonychus citri, Tetranychus arabicus, Tetranychus kanzawai, Tetranychus urticae, many others
Physical state	White crystals
Related substances & organisms	sodium lignosulfonate dimethoate hexythiazox tetradifon

Formulations

Property	Value
Example manufacturers & suppliers of products using this active now or historically	Carbax Mitigan Acarin Mitex kelthane Hilfol
Example products using this active	Agan Chemical Makhteshim-Agan Rohm & Hass Sedagri
Formulation and application details	Usually supplied as emulsifiable concentrates and wettable powders

ENVIRONMENTAL FATE

Property		Value	Source; quality score; and other information	Interpretation
Solubility - In water at 20 °C (mg l⁻¹)		0.8	B5 B = UK CRD and ACP evaluation documents / and other Defra (UK) documents (click here ) 5 = Verified data used for regulatory purposes	Low
Solubility - In organic solvents at 20 °C (mg l⁻¹)		2600000	C4 C = AGRITOX (click here ) 4 = Verified data Dichloromethane	-
		2750000	C4 C = AGRITOX (click here ) 4 = Verified data Methanol	-
		1350000	C4 C = AGRITOX (click here ) 4 = Verified data Xylene	-
		400000	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source Acetone	-
Melting point (°C)		370.5	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	-
Boiling point (°C)		193	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source	-
Degradation point (°C)		-	-	-
Flashpoint (°C)		193	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source (open cup)	-
Octanol-water partition coefficient at pH 7, 20 °C	P	2.00 X 1004	Calculated	-
	Log P	4.3	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source	High
Bulk density (g ml⁻¹)		1.45	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)		0.25	B5 B = UK CRD and ACP evaluation documents / and other Defra (UK) documents (click here ) 5 = Verified data used for regulatory purposes	Low volatility
Henry's law constant at 25 °C (Pa m³ mol⁻¹)		2.45 X 10-02	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)	80	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source	Moderately persistent
	DT₅₀ (lab at 20 °C)	45	DW4 DW = Don Wauchope personal database for Pka data: Wauchope, R. D. and Edwards, J. Dissociation constants for pesticide active ingredients: a database and comparison with predicted values. MS in preparation 4 = Verified data	Moderately persistent
	DT₅₀ (field)	-	-	-
	DT₉₀ (lab at 20 °C)	-	-	-
	DT₉₀ (field)	-	-	-
	DT₅₀ modelling endpoint	-	-	-
	Note	Best available data DT₅₀ range 40-80 days
Dissipation rate RL₅₀ on plant matrix	Value	3.7	R4 R = Peer reviewed scientific publications 4 = Verified data	-
	Note	Published literature RL₅₀ range 1.7-5.9 days, 5 field & undercover grown crops, various matrices, n=6
Dissipation rate RL₅₀ on and in plant matrix	Value	2.7	R4 R = Peer reviewed scientific publications 4 = Verified data	-
	Note	Published literature RL₅₀ range 2.6-2.8 days, 36 field crops, various matrices, n=3
Aqueous photolysis DT₅₀ (days) at pH 7	Value	26	K3 K = Research datasets, e.g. Pandora, Demetra 3 = Unverified data of known source	Slow
	Note	-
Aqueous hydrolysis DT₅₀ (days) at 20 °C and pH 7	Value	3.3	K3 K = Research datasets, e.g. Pandora, Demetra 3 = Unverified data of known source	Non-persistent
	Note	pH sensitive: DT₅₀ 85 days at pH 5, 26 minutes at pH 9 (L3)
Water-sediment DT₅₀ (days)		29	K2 K = Research datasets, e.g. Pandora, Demetra 2 = Unverified data of unknown source	Fast
Water phase only DT₅₀ (days)		-	-	-

Soil adsorption and mobility

Property		Value	Source; quality score; and other information	Interpretation
Linear	Kd	-	H3 H = The US ARS pesticide properties database (click here ) 3 = Unverified data of known source	Non-mobile
	Koc	6064
	Notes and range	Other source: 6945 mL g⁻¹ sandy soil (H3); 5000 (G3)
Freundlich	Kf	-	-	-
	Kfoc	-
	1/n	-
	Notes and range	-
pH sensitivity		-

Fate indices

Property		Value	Source; quality score; and other information	Interpretation
GUS leaching potential index		0.36	Calculated	Low leachability
SCI-GROW groundwater index (μg l⁻¹) for a 1 kg ha⁻¹ or 1 l ha⁻¹ application rate	Value	8.34 X 10-03	Calculated	-
	Note	-
Potential for particle bound transport index		High	Calculated	-
Potential for loss via drain flow		Non-mobile	Calculated	-

Key metabolites

Metabolite	Formation medium	Estimated maximum occurrence fraction	1107/2009 relevancy
2-chlorobenzoic acid (Ref: AE-C500233)	Soil	-	-

Other known metabolites

Metabolite name and reference	Aliases	Formation medium / Rate	Estimated maximum occurrence fraction	Metabolising enzymes
1-(2-chlorophenyl)-1-(4'-chlorophenyl)-2,2-dichloroethanol	-	Soil (Aerobic)	-	-
o,p-dichlorobenzohydrol	o,p-DCBH	Soil (Aerobic)	-	-
3-hydroxy-2,4-dichlorobenzophenone	OH-DCBP	Soil (Aerobic)	-	-
3-hydroxy-4,4'-dichlorobenzophenone	3-OH-DCBP	Soil (Aerobic)	-	-
1-(2-chlorophenyl)-1-(4'-chlorophenyl)-2,2-dichloroethanol (Ref: FW-152)	-	Soil (Aerobic)	-	-
1,1-bis(4-chlorophenyl)-2,2-dichloroethanole	-	Soil (Anaerobic)	-	-
2,4-dichlorobenzophenone	-	Soil (Photolysis)	-	-
2,4-dichlorobenzhydrol	-	Soil (Aerobic)	-	-

ECOTOXICOLOGY

Property		Value	Source; quality score; and other information	Interpretation
Bio-concentration factor	BCF (l kg⁻¹)	10000	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 Whole fish	High potential
	CT₅₀ (days)	Not available		-
Mammals - Acute oral LD₅₀ (mg kg⁻¹)		578	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source 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 2 year	High
	(ppm diet)	5		-
Mammals - Chronic 21d NOAEL (mg kg⁻¹ bw d⁻¹)		-	-	-
Birds - Acute LD₅₀ (mg kg⁻¹)		1418	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source Coturnix japonica	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)		0.51	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source Lepomis macrochirus	Moderate
Fish - Chronic 21 day NOEC (mg l⁻¹)		0.0044	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source Oncorhynchus mykiss	High
Aquatic invertebrates - Acute 48 hour EC₅₀ (mg l⁻¹)		0.14	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)		125	Q2 Q = Miscellaneous internet resources 2 = Unverified data of unknown source Daphnia magna	Low
Aquatic crustaceans - Acute 96 hour LC₅₀ (mg l⁻¹)		-	-	-
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)		0.075	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source Scenedemus subspicatus	Moderate
Algae - Chronic 96 hour NOEC, growth (mg l⁻¹)		0.05	Q2 Q = Miscellaneous internet resources 2 = Unverified data of unknown source Unknown species	Moderate
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)	> 50	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source	Moderate
	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)	-	-	-
	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)		43.1	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source	Moderate
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	Moderately harmful	Q2 Q = Miscellaneous internet resources 2 = Unverified data of unknown source Parasitoids	-
Other arthropod (2)	LR₅₀ g ha⁻¹	-	-	-
	% Effect	Harmful	Q2 Q = Miscellaneous internet resources 2 = Unverified data of unknown source Predatory mites	-
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)		578	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source Rat	Moderate
Mammals - Dermal LD₅₀ (mg kg⁻¹ body weight)		2500	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source Rabbit	-
Mammals - Inhalation LC₅₀ (mg l⁻¹)		5.0	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)		0.002	B4 B = UK CRD and ACP evaluation documents / and other Defra (UK) documents (click here ) 4 = Verified data UK ACP 1993	-
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	Low risk to Europeans as no longer approved for use
MRLs	European	EU MRL pesticide database
	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 ; B3 B = DNA damage/repair (EFSA database) 3 = Negative ; C3 C = Gene mutation (EFSA database) 3 = Negative ; D0 D = Genome mutation (EFSA database) 0 = No data ; E3 E = Unspecified genotoxicity type (miscellaneous data source) 3 = Negative ?Possibly, status not identified Reproduction / development effects Acetyl cholinesterase inhibitor Neurotoxicant No data found XNo, known not to cause a problem ✓Yes, known to cause a problem Respiratory tract irritant Skin irritant Skin sensitiser ✓Yes, known to cause a problem ✓Yes, known to cause a problem ?Possibly, status not identified Eye irritant Phototoxicant   ✓Yes, known to cause a problem No data found
General human health issues		Harmful by inhalation, ingestion and through skin contact IARC group 3 carcinogen; USEPA - possible human carcinogen Endocrine issues - Inhibition of androgen synthesis

Handling issues

Property	Value and interpretation
General	No information available
CLP classification 2013	Health: H302, H312, H315, H317 Environment: H400, H410
EC Risk Classification	Xn - Harmful: R21/22, R43 Xi - Irritant: R38 N - Dangerous for the environment: R50, R53
EC Safety Classification	S2, S36/37, S60, S61
WHO Classification	II (Moderately hazardous)
UN Number	-
Waste disposal & packaging	-

TRANSLATIONS

Language	Name
English	dicofol
French	dicofol
German	Dicofol
Danish	dicofol
Italian	dicofol
Spanish	dicofol
Greek	dicofol
Polish	dikofol
Swedish	-
Hungarian	-
Dutch	dicofol

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Record last updated:	11/01/2021
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