2,4,5-trichlorophenol	Last updated: 24/05/2025
(Also known as: TCP; 2,4,5-TCP; trichlorophenol)

---

SUMMARY

2,4,5-trichlorophenol is a substance with fungal, herbicidal and bacterial activity. It is highly soluble in water has a low volatility and is slightly mobile in soil systems. It is moderately toxic to most biodiversity. 2,4,5-trichlorophenol has a moderate oral mammalian toxicity, is a neurotoxin and an irritant.

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: Slightly mobile Warning: Significant data are missing	Ecotoxicity Moderate alert: Fish acute ecotoxicity: Moderate; Fish chronic ecotoxicity: Moderate; Daphnia acute ecotoxicity: Moderate; Daphnia chronic ecotoxicity: Moderate; Bees acute unknown ecotoxicity: Moderate; Earthworms acute ecotoxicity: Moderate	Human health High alert: Neurotoxicant

GENERAL INFORMATION

Description	Active substance and pesticide transformation product with fungicial and herbicidal action, used particularly for the control of broadleaved weeds in grass
Example pests controlled	Gorse; Brush weeds; Thistles; Blight
Example applications	Solanaceous crops; Vegetables; Turf
Efficacy & activity	-
Availability status	Considered obsolete but may be available in some countries; Banned in many countries
Introduction & key dates	circa 1945, 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 plant protection agent

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	2,4,5-trichlorophenol is one of six isomers of trichlorophenol (2,3,4-; 2,3,5-; 2,3,6-; 2,4,5-, 2,4,6- and 3,4,5-)
Chemical formula	C₆H₃Cl₃O
Canonical SMILES	C1=C(C(=CC(=C1Cl)Cl)Cl)O
Isomeric SMILES	No data
International Chemical Identifier key (InChIKey)	LHJGJYXLEPZJPM-UHFFFAOYSA-N
International Chemical Identifier (InChI)	InChI=1S/C6H3Cl3O/c7-3-1-5(9)6(10)2-4(3)8/h1-2,10H
2D structure diagram/image available?	Yes

General status

Pesticide type	Fungicide; Herbicide; Metabolite; Algicide; Other substance
Metabolite Type	Soil; Plant
Other bioactivity & uses	Impurity; Bactericide
Substance groups	Organochloride fungicide; Organochloride herbicide; Organochloride biocide; Phenolic compound
Minimum active substance purity	-
Known relevant impurities	-
Substance origin	Synthetic
Mode of action	Causes distorted growth that affects respiration and cell function
CAS RN	95-95-4
EC number	202-467-8
CIPAC number	6
US EPA chemical code	064210
PubChem CID	44147467
CLP index number	604-017-00-X
Molecular mass	197.45
PIN (Preferred Identification Name)	-
IUPAC name	1-hydroxy-2,4,5-trichlorobenzene
CAS name	2,4,5-trichlorophenol
Other status information	POP; Chemical subject to PIC regulations
Relevant Environmental Water Quality Standards	-
Herbicide Resistance Class (HRAC MoA class)	Not known
Herbicide Resistance Class (WSSA MoA class)	Not known
Insecticide Resistance Class (IRAC MoA class)	Not applicable
Fungicide Resistance Class (FRAC MOA class)	Not known
Examples of recorded resistance	-
Physical state	Grey crystalline solid
Related substances & organisms	2,4,5-trichlorophenoxyacetic acid

Can be a metabolite of:

Parent	Formation medium	Estimated maximum occurrence fraction	1107/2009 relevancy
2,3,6-TBA	Soil	-	-

Formulations

Property	Value
Example manufacturers & suppliers of products using this active now or historically	-
Example products using this active	Dowcide 2 Collunosol
Formulation and application details	-

ENVIRONMENTAL FATE

Property		Value	Source; quality score; and other information	Interpretation
Solubility - In water at 20 °C (mg l⁻¹)		1200	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)		-	-	-
Melting point (°C)		68	V3 V = ChemID Online Databases; Chemspider; PubChem. (ChemID ) 3 = Unverified data of known source	-
Boiling point (°C)		247	V3 V = ChemID Online Databases; Chemspider; PubChem. (ChemID ) 3 = Unverified data of known source	-
Degradation point (°C)		-	-	-
Flashpoint (°C)		-	-	-
Octanol-water partition coefficient at pH 7, 20 °C	P	5.25 X 1003	Calculated	-
	Log P	3.72	V3 V = ChemID Online Databases; Chemspider; PubChem. (ChemID ) 3 = Unverified data of known source	High
Fat solubility of residues	Solubility	Likely to be soluble	Q3 Q = Miscellaneous data from online sources 3 = Unverified data of known source	-
	Data type	Based on chemical group	Q3 Q = Miscellaneous data from online sources 3 = Unverified data of known source	-
Density (g ml⁻¹)		1.68	V3 V = ChemID Online Databases; Chemspider; PubChem. (ChemID ) 3 = Unverified data of known source	-
Dissociation constant pKa) at 25 °C		7.4	V3 V = ChemID Online Databases; Chemspider; PubChem. (ChemID ) 3 = Unverified data of known source	-
		Weak acid
Vapour pressure at 20 °C (mPa)		0.0029	Q3 Q = Miscellaneous data from online sources 3 = Unverified data of known source	Low volatility
Henry's law constant at 25 °C (Pa m³ mol⁻¹)		0.16	V3 V = ChemID Online Databases; Chemspider; PubChem. (ChemID ) 3 = Unverified data of known source	Moderately 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)	-	-	-
	DT₅₀ (lab at 20 °C)	-	-	-
	DT₅₀ (field)	-	-	-
	DT₉₀ (lab at 20 °C)	-	-	-
	DT₉₀ (field)	-	-	-
	DT₅₀ modelling endpoint	-	-	-
	Note	-
Dissipation rate RL₅₀ (days) on plant matrix	Value	11.3	R3 R = Peer reviewed scientific publications 3 = Unverified data of known source	-
	Note	Turfgrass, 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)	-	Q2 Q = Miscellaneous data from online sources 2 = Unverified data of unknown source	Slightly mobile
	Koc (mL g⁻¹)	836
	Notes and range	Estimated
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		-	-	-
SCI-GROW groundwater index (μg l⁻¹) for a 1 kg ha⁻¹ or 1 l ha⁻¹ application rate	Value	Cannot be calculated	-	-
	Note	-
Potential for particle bound transport index		-	-	-
Potential for loss via drain flow		Slightly mobile	Calculated	-
Photochemical oxidative DT₅₀ (hrs) as indicator of long-range air transport risk		-	-	-
Bio-concentration factor	BCF (l kg⁻¹)	131	Q2 Q = Miscellaneous data from online sources 2 = Unverified data of unknown source	Threshold for concern
	CT₅₀ (days)	Not available		-

Known metabolites

None

ECOTOXICOLOGY

Terrestrial ecotoxicology

Property		Value	Source; quality score; and other information	Interpretation
Mammals - Acute oral LD₅₀ (mg kg⁻¹)		820	V3 V = ChemID Online Databases; Chemspider; PubChem. (ChemID ) 3 = Unverified data of known source Rat	Moderate
Mammals - Short term dietary NOEL	(mg kg⁻¹)	-	-	-
	(ppm diet)	-		-
Mammals - Chronic 21d NOAEL (mg kg⁻¹ bw d⁻¹)		-	-	-
Birds - Acute LD₅₀ (mg kg⁻¹)		-	-	-
Birds - Short term dietary (LC₅₀/LD₅₀)		-	-	-
Birds - Chronic 21d NOEL (mg kg⁻¹ bw d⁻¹)		-	-	-
Earthworms - Acute 14 day LC₅₀ (mg kg⁻¹)		46	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 Eisenia andrei	Moderate
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)	-	-	-
	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)	> 50	Q3 Q = Miscellaneous data from online sources 3 = Unverified data of known source	Moderate
	Chronic	-	-	-
	Notes	-
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)	-	-	-
	Mode of exposure	-
Other bee species (2)	Acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg insect⁻¹)	-	-	-
	Mode of exposure	-
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)		0.49	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)		0.0625	P3 P = Other non-EU, UK or US Governments and Regulators 3 = Unverified data of known source Oncorhynchus mykiss	Moderate
Tropical Freshwater Fish - Acute 96 hour LC₅₀ (mg l⁻¹)		-	-	-
Temperate Freshwater Aquatic invertebrates - Acute 48 hour EC₅₀ (mg l⁻¹)		0.9	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 Daphnia magna	Moderate
Temperate Freshwater Aquatic invertebrates - Chronic 21 day NOEC (mg l⁻¹)		0.375	P3 P = Other non-EU, UK or US Governments and Regulators 3 = Unverified data of known source Daphnia magna	Moderate
Tropical Freshwater Aquatic invertebrates - Acute 48 hour EC₅₀ (mg l⁻¹)		> 1.34	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	Moderate
Aquatic crustaceans - Acute 96 hour LC₅₀ (mg l⁻¹)		3.83	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	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 (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)		1.2	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 Pseudokirchneriella subcapitata	Moderate
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)		820	V3 V = ChemID Online Databases; Chemspider; PubChem. (ChemID ) 3 = Unverified data of known source Rat	Moderate
Mammals - Dermal LD₅₀ (mg kg⁻¹ body weight)		-	-	-
Mammals - Inhalation LC₅₀ (mg l⁻¹)		-	-	-
Other Mammal toxicity endpoints		-	-	-
ADI - Acceptable Daily Intake (mg kg⁻¹ bw day⁻¹)		0.03	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	-
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	Negligible risk to bystanders
	Occupational	Exposure may occur via inhalation or skin absorption
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 ?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 ; E0 E = Unspecified genotoxicity type (miscellaneous data source) 0 = No data ?Possibly, status not identified Reproduction / development effects Acetyl cholinesterase inhibitor Neurotoxicant ?Possibly, status not identified 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 No data found Eye irritant Phototoxicant   ✓Yes, known to cause a problem No data found
General human health issues		IARC listed carcinogen 2B May be toxic to gastrointestinal tract, skin May cause hypotension, myocardial failure and pulmonary edema

Handling issues

Property	Value and interpretation
General	Corrosive Not expected to auto-ignite; Not highly flammable IMDG Transport Hazard Class 6.1
CLP classification 2013	Health: H302, H315, H319 Environment: H400, H410
WHO Classification	Not classified: Obsolete (Not classified: Obsolete)
UN Number	UN2020
Waste disposal & packaging	{Packaging Group III (minor danger)
Shelf-life, storage, stability and reactivity	-

TRANSLATIONS

Language	Name
English	2,4,5-trichlorophenol
French	-
German	-
Danish	2,4,5-trichlorphenol
Italian	-
Spanish	-
Greek	-
Polish	2,4,5-trichlorofenol
Swedish	-
Hungarian	-
Dutch	-
Norwegian	-

---

Record last updated:	24/05/2025
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