Tea tree oil	Last updated: 15/02/2026
(Also known as: tea tree extract)

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Hazard alerts

The following Pesticide Hazard Tricolour (PHT) 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. The alerts for Highly Hazardous Pesticides (HHPs) are based on applying the FAO/WHO (Type 1) and the PAN (Type II) criteria to PPDB data. Further details on the HHP indicators are given in the tables below. Neither the PHT nor the HHP hazard alerts take account of usage patterns or exposure, thus they do not represent risk.

PHT: Environmental fate	PHT: Ecotoxicity	PHT: Human health	Highly Hazardous Pesticide
	Ecotoxicity Moderate alert: Fish acute ecotoxicity: Moderate; Daphnia acute ecotoxicity: Moderate; Bees acute oral ecotoxicity: Moderate	Human health Low alert

GENERAL INFORMATION

Description	Tee Tree Oil is a complex mixture of chemicals and can be exploited for its fungicidal and antimicrobial properties
Example pests controlled	Powdery mildew; Damping-off, Crown rot; Grey mold; Root rot
Example applications	Potatoes; Carrots; Herbs; Cucumbers; Tomatoes; Peppers; Watermelon; Grapes, Ornamentals
Efficacy & activity	-
Appearance and life cycle	-
Taxonomic classification	Class: Magnoliopsida; Order: Myrtales; Family: Myrtaceae

GB regulatory status

GB COPR regulatory status	Not approved
Date COPR inclusion expires	Withdrawn
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	Approved
Dossier rapporteur/co-rapporteur	Poland/Belgium
Date EC 1107/2009 inclusion expires	31/01/2026
EU Candidate for substitution (CfS)	No
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	Morocco

Chemical structure

Isomerism	Tea tree oil is a complex natural and many of its constituents exhibit both structural and stereoisomeric isomerism. These include the three structural isomers of terpinene, terpinen-4-ol that is part of a family of compounds that includes optical isomers, cineole that is known to have stereoisomeric forms and the structural isomers of pinene.
Chemical formula	-
Canonical SMILES	-
Isomeric SMILES	-
International Chemical Identifier key (InChIKey)	-
International Chemical Identifier (InChI)	-
2D structure diagram/image available?	No

General status

Biopesticide type		Fungicide
Other bioactivity & uses		Antimicrobial
Substance groups		Plant-derived substance; Plant oil
Minimum active substance purity		-
Known relevant impurities		-
Substance origin		Natural; Complex mixture
Mode of action		Via the disruption of the structural and functional integrity of bacterial membrane, inhibiting the formation of germ tubes, or mycelial conversion and by suppressing superoxide production
Substance source		Extracted for the Tea tree shrub (Melaleuca alternifolia), a species of tree or tall shrub in the myrtle family
Mixture composition		Tea tree oil is a complex mixture of over 100 volatile compounds, predominantly monoterpenes, sesquiterpenes, and their oxygenated derivatives. Its composition is standardised by the international norm ISO 4730:2017 ("Oil of Melaleuca, terpinen-4-ol type"), which defines acceptable ranges for key components to ensure quality and consistency in commercial products. The dominant and most biologically active constituent is terpinene-4-ol (35-48%). Other major components include: gamma-terpinene (14-28%), alpha-terpinene (6-12%), 1,8-vineole ( traces to 10%), terpinolene (1.5–5%), p-cymene (0.5-8%), alpha-pinene (1-6%) and alpha-terpineol (2-8%). Minor but notable sesquiterpenes include aromadendrene (0.2-3%), ledene/viridiflorene (0.1-3%).
Uses		Crop protection
Target pests		Powdery mildew; Damping-off, Crown rot; Grey mould; Root rot
Target host		Potatoes; Carrots; Herbs; Cucumbers; Tomatoes; Peppers; Watermelon; Grapes, Ornamentals
Farming system suitability		-
CAS RN		68647-73-4
EC number		285-377-1
CIPAC number		-
US EPA chemical code		-
PubChem CID		-
Molecular mass		-
Chemical name		tea tree oil
PIN (Preferred Identification Name)		-
IUPAC name		-
CAS name		-
Global Governance status: Listed (✓) under		UK Poisons List Order 1972 Rotterdam Convention Montreal Protocol XNo The Poisons List Order 1972 XNo Rotterdam Convention XNo Montreal Protocol Stockholm Convention OSPAR EU Water Framework Directive XNo Stockholm Convention XNo OSPAR XNo EU Water Framework Directive
Relevant Environmental Water Quality Standards		-
Forever chemical		-
Highly Hazardous Pesticide (HHP)	Type I	-
	Type II	-
Other status information		-
Herbicide Resistance Class (HRAC MoA class)		Not applicable
Herbicide Resistance Class (WSSA MoA class)		Not applicable
Insecticide Resistance Class (IRAC MoA class)		Not applicable
Fungicide Resistance Class (FRAC MOA class)		46
Examples of recorded resistance		-
Physical state		Pale straw coloured liquid comprised of a complex nd variable mixture of botanicl chemicals including terpinen-4-ol (35 to 45%), gamma-terpinene (14 to 28%), alpha-terpinene (6 to 12%) and 1,8-cineole (0 to 10%)
Related substances & organisms		terpinen-4-ol gamma-terpinene alpha-terpinene 1,8-cineole weeping paperbark oil

Commercial

Property	Value
Availability status	Current
Introduction & key dates	1920s, start of production
Example manufacturers & suppliers of products using this active now or historically	Syngenta AG Summit Agro USA
Example products using this active	Timorex Gold Timorex Act
Formulation and application details	Often formulated as liquid concetrates and ready-to-use products
Commercial production	The oil is produced through steam distillation of the leaves and terminal branchlets of the tea tree shrub (Melaleuca alternifolia)
Impact on climate of production and use	While specific data for tea tree oil is scarce, similar essential oils (like eucalyptus or lavender) have estimated carbon footprints ranging from 1.5 to 5 kg CO₂e per kg of oil, depending on farming practices and energy sources used in distillation. This is in line with general data for plant oils which have been estimated at between 1.0 and 4.0 kg CO₂e per kg of oil.

ENVIRONMENTAL FATE

Property		Value	Source; quality score; and other information	Interpretation
Solubility - In water at 20 °C at pH 7 (mg l⁻¹)		-	-	-
Solubility - In organic solvents at 20 °C (mg l⁻¹)		-	-	-
Melting point (°C)		-	-	-
Boiling point (°C)		-	-	-
Degradation point (°C)		-	-	-
Flashpoint (°C)		39	E4 E = Manufacturers safety data sheets 4 = Verified data	-
Octanol-water partition coefficient at pH 7, 20 °C	P	-	-	-
	Log P	-	-	-
Fat solubility of residues	Solubility	-	-	-
	Data type	-	-	-
Density (g ml⁻¹)		0.925	E4 E = Manufacturers safety data sheets 4 = Verified data	-
Dissociation constant pKa) at 25 °C		-	-	-
		-
Vapour pressure at 20 °C (mPa)		-	-	-
Henry's law constant at 25 °C (Pa m³ mol⁻¹)		-	-	-
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		Readily biodegradable
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	-	-	-
	Note	-
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)	-	-	-
	Koc (mL g⁻¹)	-
	Notes and range	-
Freundlich	Kf (mL g⁻¹)	-	-	-
	Kfoc (mL g⁻¹)	-
	1/n	-
	Notes and range	-
pH sensitivity		-

Known metabolites

None

ECOTOXICOLOGY

Terrestrial ecotoxicology

Property		Value	Source; quality score; and other information	Interpretation
Mammals - Acute oral LD₅₀ (mg kg⁻¹)		> 2000	E4 E = Manufacturers safety data sheets 4 = Verified data Rat	Low
Mammals - Short Term Oral NOAEL (mg kg⁻¹ bw d⁻¹)		-	-	-
Mammals - Long Term (Chronic) Oral NOAEL (mg kg⁻¹ bw d⁻¹)		-	-	-
Birds - Acute LD₅₀ (mg kg⁻¹)		> 2000	R4 R = Peer reviewed scientific publications 4 = Verified data Colinus virginianus	Low
Birds - Short term dietary LC₅₀ (mg kg⁻¹ bw d⁻¹)		-	-	-
Birds - Chronic 21d NOEL (mg kg⁻¹ bw d⁻¹)		-	-	-
Earthworms - Acute 14 day LC₅₀ (mg kg⁻¹ dw soil)		-	-	-
Earthworms - Chronic NOEC, reproduction (mg kg⁻¹ dw soil)		-	-	-
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)	> 331	R4 R = Peer reviewed scientific publications 4 = Verified data Apis mellifera	Low
	Oral acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)	> 66.0	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 Apis mellifera	Moderate
	Unknown mode acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)	-	-	-
	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)		-	-	-
Beneficial insects (Butterflies)	Contact	-	-	-
	Notes	-
	Oral	-	-	-
	Notes	-

Aquatic ecotoxicology

Property		Value	Source; quality score; and other information	Interpretation
Temperate Freshwater Fish - Acute 96 hour LC₅₀ (mg l⁻¹)		5.67	R4 R = Peer reviewed scientific publications 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)		1.45	R4 R = Peer reviewed scientific publications 4 = Verified data Daphnia magna	Moderate
Temperate Freshwater Aquatic invertebrates - Chronic 21 day NOEC (mg l⁻¹)		-	-	-
Tropical Freshwater Aquatic invertebrates - Acute 48 hour EC₅₀ (mg l⁻¹)		-	-	-
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) (EC₅₀)		7.21	R4 R = Peer reviewed scientific publications 4 = Verified data Desmodesmus subspicatus	Moderate
Algae - Chronic (growth rate, fresh; mg l⁻¹)		-	-	-
Mesocosm study data	NOEAEC mg l⁻¹	-	-	-
	NOEAEC mg l⁻¹	-	-	-
Marine bivalves		-	-	-

Regulatory Threshold Levels (RTLs)

Note: These RTLs have been calculated using the regulatory approach used in the European Union and based on ecotoxocity values in the PPDB.

Species group	RTL	Notes
Mammals	200	Worst case of acute and chronic mammals
Birds	200	Worst case of acute and chronic birds
Soil organisms	No data	No data for acute and chronic earthworms
Terrestrial plants	No data	No data for non-target plants vegetative vigour and seedling emergence
Pollinators	1.32	Worst case of contact and oral honeybees
Arthropods	No data	No data for parasitic wasps and predatory mites
Fish	0.0567	Worst case of temperate acute and chronic fish
Aquatic invertebrates	0.0145	Worst case of temperate acute and chronic aquatic invertebrates
Aquatic plants	0.721	Worst case of free-floating plants, rooted plants, acute and chronic algae

HUMAN HEALTH AND PROTECTION

General

Property		Value	Source; quality score; and other information	Interpretation
Threshold of Toxicological Concern (Cramer Class)		-	-	-
Mammals - Acute oral LD₅₀ (mg kg⁻¹)		> 2000	E4 E = Manufacturers safety data sheets 4 = Verified data Rat	Low
Mammals - Short Term Oral NOAEL (mg kg⁻¹ bw d⁻¹)		-	-	-
Mammals - Long Term (Chronic) Oral NOAEL (mg kg⁻¹ bw d⁻¹)		-	-	-
Mammals - Dermal LD₅₀ (mg kg⁻¹ body weight)		> 2000	E4 E = Manufacturers safety data sheets 4 = Verified data Rat	-
Mammals - Inhalation LC₅₀ (mg l⁻¹)		-	-	-
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		-	-	-

Health issues

Specific human health issues (hazard-based)		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 ; E0 E = Unspecified genotoxicity type (miscellaneous data source) 0 = No data XNo, known not to cause a problem Reproduction / development effects Acetyl cholinesterase inhibitor Neurotoxicant No data found XNo, known not to cause a problem XNo, known not to cause a problem Respiratory tract irritant Skin irritant Skin sensitiser ?Possibly, status not identified ✓Yes, known to cause a problem ✓Yes, known to cause a problem Eye irritant Phototoxicant   ✓Yes, known to cause a problem No data found
General human health issues		Tea tree oil is not a substance of serios toxicological concern when used as a pesticide but is an irritant

Handling issues

Property	Value and interpretation
General	Flammable Use foam, carbon dioxide or dry chemical for fire fighting Portect against electrostatic charges Not explosive or oxidising IMDG Transport Hazard Class 3
CLP classification 2013	-
WHO Classification	Not listed (Not listed)
UN Number	UN1993
Waste disposal & packaging	-
Shelf-life, storage, stability and reactivity	-

TRANSLATIONS

Language	Name
English	tea tree oil
French	-
German	-
Danish	-
Italian	-
Spanish	-
Greek	-
Polish	-
Swedish	-
Hungarian	-
Dutch	-
Norwegian	-

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Record last updated:	15/02/2026
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

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