Tralomethrin (Ref: OMS 3048)	Last updated: 15/09/2025
(Also known as: tralomethrine; HAG 107; RU 25474)

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GENERAL INFORMATION

Description	A pyrethroid ester insecticide
Examples of veterinary uses	Used for general control of insect pests associated with animals
Examples of species treated	Cats; Dogs

Approval status

VMR 2013/2033 approval status (GB/UK)	Not approved
EU Regulatory approval status	Not approved

Chemical structure

Isomerism	Tralomethrin exhibits stereoisomerism, specifically chiral and epimeric forms, due to the presence of multiple stereocenters in its cyclopropane carboxylate structure. As a synthetic pyrethroid insecticide, it contains asymmetric carbon atoms that give rise to a mixture of stereoisomers.
Chemical formula	C₂₂H₁₉Br₄NO₃
Canonical SMILES	CC1(C(C1C(=O)OC(C#N)C2=CC(=CC=C2)OC3=CC=CC=C3)C(C(Br)(Br)Br)Br)C
Isomeric SMILES	CC1([C@H]([C@H]1C(=O)O[C@H](C#N)C2=CC(=CC=C2)OC3=CC=CC=C3)C(C(Br)(Br)Br)Br)C
International Chemical Identifier key (InChIKey)	YWSCPYYRJXKUDB-KAKFPZCNSA-N
International Chemical Identifier (InChI)	InChI=1S/C22H19Br4NO3/c1-21(2)17(19(23)22(24,25)26)18(21)20(28)30-16(12-27)13-7-6-10-15(11-13)29-14-8-4-3-5-9-14/h3-11,16-19H,1-2H3/t16-,17-,18+,19+/m1/s1
2D structure diagram/image available?	Yes

General status

Veterinary substance type	Ecotoparasiticide
Substance groups	Pyrethroid insecticide; Pyrethroid ester insecticide
Minimum active substance purity	-
Known relevant impurities	-
Substance origin	Synthetic
Mode of action	Non-systemic with contact and stomach action. Sodium channel modulator.
Molecular targets	[Sodium channel, Modulator]
CAS RN	66841-25-6
EC number	266-493-1
CIPAC number	-
US EPA chemical code	121501
PubChem CID	48132
Therapeutic Class	-
ATCvet Code	None allocated
Controlled Drug?	No
Regulation 37/2010 MRL Classification	-
Molecular mass	665.0
PIN (Preferred Identification Name)	(S)-cyano(3-phenoxyphenyl)methyl (1R,3S)-2,2-dimethyl-3-[(1?)-1,2,2,2-tetrabromoethyl]cyclopropane-1-carboxylate
IUPAC name	(S)-α-cyano-3-phenoxybenzyl (1R,3S)-2,2-dimethyl-3-[(RS)-1,2,2,2-tetrabromoethyl]cyclopropanecarboxylate
CAS name	(S)-cyano(3-phenoxyphenyl)methyl (1R,3S)-2,2-dimethyl-3-(1,2,2,2-tetrabromoethyl)cyclopropanecarboxylate
Forever chemical	-
Other status information	PAN listed Highly Hazardous Chemical
Relevant Environmental Water Quality Standards	-
Physical state	Yellow resinous solid
Related substances & organisms	permethrin transpermethrin

Commercial

Property	Value
Availability status	Current
Introduction & key dates	1993, first registration USA; 2023, withdrawn UK
Example manufacturers & suppliers of products using this active now or historically	Aventis
Example products using this active	Scout-X-TRA Hotshot Rid a bug Spectracide
Formulation and application details	Formulations included emulsifiable concentrates, gels, and sprays
Commercial production	The commercial production of tralomethrin involves a complex multi-step synthesis typical of pyrethroid insecticides, beginning with the formation of a cyclopropane carboxylic acid derivative that serves as the core structure. This is then esterified with a (S)-cyano-(3-phenoxyphenyl)methanol moiety, resulting in a molecule with multiple chiral centres and epimeric forms.
Impact on climate of production and use	Data for the amount of life cycle GHGs produced by tralomethrin are not available in the public domain. However, whilst estimates vary, more general data suggests that between 14 and 19 kilograms of CO₂e is emitted per kilogram of insecticide produced.

ENVIRONMENTAL FATE

Property		Value	Source; quality score; and other information	Interpretation
Solubility - In water at 20 °C (mg l⁻¹)		0.08	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source	Low
Solubility - In organic solvents at 20 °C (mg l⁻¹)		1000000	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source Xylene	-
		1000000	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source Toluene	-
		1000000	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source Acetone	-
Melting point (°C)		143	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source	-
Boiling point (°C)		-	-	-
Degradation point (°C)		-	-	-
Flashpoint (°C)		26	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source	-
Octanol-water partition coefficient at pH 7, 20 °C	P	1.00 X 1005	Calculated	-
	Log P	5	L2 L = Pesticide manuals and hard copy reference books / other sources 2 = Unverified data of unknown source	High
Fat solubility of residues	Solubility	-	-	-
	Data type	-	-	-
Density (g ml⁻¹)		1.7	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)		4.80 X 10-06	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)		1.60 X 10-10	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)		-	-	-
Refractive Index		-	-	-
Environmental release		-

Degradation

Property		Value	Source; quality score; and other information	Interpretation
Soil degradation (days) (aerobic)	DT₅₀ (typical)	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	Non-persistent
	DT₅₀ (lab at 20 °C)	27	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	Non-persistent
	DT₅₀ (field)	-	-	-
	DT₉₀ (lab at 20 °C)	-	-	-
	DT₉₀ (field)	-	-	-
	Note	Best available data
Manure DT₅₀ (days)		-	-	-
Aqueous photolysis DT₅₀ (days) at pH 7	Value	0.05	R3 R = Peer reviewed scientific publications 3 = Unverified data of known source	Fast
	Note	-
Aqueous hydrolysis DT₅₀ (days) at 20 °C and pH 7	Value	Stable	W4 W = French database provided by ARVALIS-Institut du Végétal. Dataset no longer available. 4 = Verified data	Stable
	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)	-	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source	Non-mobile
	Koc (mL g⁻¹)	359732
	Notes and range	Best available data
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		-2.23	Calculated	Low leachability
Bio-concentration factor	BCF (l kg⁻¹)	1200	J4 J = Pesticide Action Network database (click here ) 4 = Verified data	Threshold for concern
	CT₅₀ (days)	Not available		-

Known soil metabolites

Metabolite	Major/Minor fraction	Estimated maximum occurrence fraction	Notes
deltamethrin (Ref: OMS 1998)	Major fraction	0.400	-

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)		99	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)	0.75	L2 L = Pesticide manuals and hard copy reference books / other sources 2 = Unverified data of unknown source Rat 2 yr	High
	(ppm diet)	-		-
Mammals - Chronic 21d NOAEL (mg kg⁻¹ bw d⁻¹)		-	-	-
Birds - Acute LD₅₀ (mg kg⁻¹)		> 2510	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source Phasianidae	Low
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	Vegetative vigour ER₅₀ (g ha⁻¹)	-	-	-
	Seedling emergence ER₅₀ (g ha⁻¹)	-	-	-
Honeybees (Apis spp.)	Contact acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)	0.13	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
	Oral acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)	-	-	-
	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 0.5 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)	0.011	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)	1.27	R4 R = Peer reviewed scientific publications 4 = Verified data Nomia melanderi	Moderate
	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)		0.0016	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source Oncorhynchus mykiss	High
Temperate Freshwater Fish - Chronic 21 day NOEC (mg l⁻¹)		0.000088	P3 P = Other non-EU, UK or US Governments and Regulators 3 = Unverified data of known source Pimephales promelas survival	High
Tropical Freshwater Fish - Acute 96 hour LC₅₀ (mg l⁻¹)		-	-	-
Temperate Freshwater Aquatic invertebrates - Acute 48 hour EC₅₀ (mg l⁻¹)		0.000038	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source Daphnia magna	High
Temperate Freshwater Aquatic invertebrates - Chronic 21 day NOEC (mg l⁻¹)		0.0000544	P3 P = Other non-EU, UK or US Governments and Regulators 3 = Unverified data of known source Daphnia magna	High
Tropical Freshwater Aquatic invertebrates - Acute 48 hour EC₅₀ (mg l⁻¹)		> 0.00014	R4 R = Peer reviewed scientific publications 4 = Verified data Ceriodaphnia dubia	High
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 (free-floating, fonds growth, fresh) - 7 day (mg l⁻¹)		-	-	-
Aquatic plants (rooted, growth rate, fresh) - 14 day (mg l⁻¹)		-	-	-
Algae - Acute (growth rate, fresh; mg l⁻¹)		-	-	-
Algae - Chronic (growth rate, fresh; 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)		99	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)		2000	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source Rabbit	-
Mammals - Inhalation LC₅₀ (mg l⁻¹)		0.4	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		-	-	-
Exposure Routes	Public	-
	Occupational	-
Mammalian dose elimination route and rate		Excreted hrough faecal and urinary routes following hepatic metabolism	Q3 Q = Miscellaneous data from online sources 3 = Unverified data of known source	-

Health issues

Specific human health issues		Carcinogen Genotoxic Endocrine disruptor XNo, known not to cause a problem 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 ; E0 E = Unspecified genotoxicity type (miscellaneous data source) 0 = No data No data found Reproduction / development effects Acetyl cholinesterase inhibitor Neurotoxicant ?Possibly, status not identified XNo, known not to cause a problem XNo, known not to cause a problem Respiratory tract irritant Skin irritant Skin sensitiser No data found ✓Yes, known to cause a problem No data found Eye irritant Phototoxicant   ✓Yes, known to cause a problem No data found
General human health issues		No further information available

Handling issues

Property	Value and interpretation
General	IMDG Transport Hazard Class 6.1
CLP classification 2013	Health: H302, H315, H319 Environment: H400, H410
WHO Classification	II (Moderately hazardous)
UN Number	UN3349
Waste disposal & packaging	-
Shelf-life, storage, stability and reactivity	-

TRANSLATIONS

Language	Name
English	tralomethrin
French	tralomethrine
German	Tralomethrin
Danish	tralomethrin
Italian	tralometrina
Spanish	tralometrina
Greek	-
Polish	tralometryna
Swedish	-
Hungarian	-
Dutch	-
Norwegian	-

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Record last updated:	15/09/2025
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