Bulnesol	Last updated: 23/02/2026
(Not known by any other names)

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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
		Human health Low alert Warning: Significant data are missing

GENERAL INFORMATION

Description	A botanical substance found in certain plant essential oils and which has some insecticide and repellency activity
Example pests controlled	Mites (Tetranychus urticae, Varroa destructor); Whiteflies; Aphids; Thrips; Leafminers; Nematodes (Meloidogyne spp.).
Example applications	Most horticulture & greenhouse crops including tomatoes, peppers and cucumbers; Fruit trees; Ornamentals; Residential & public spaces
Efficacy & activity	-
Appearance and life cycle	-
Taxonomic classification	-

GB regulatory status

GB COPR regulatory status	Not approved
Date COPR inclusion expires	Not applicable
GB LERAP status	No UK approval for use as a pest control 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	Not applicable
EU Candidate for substitution (CfS)	Not applicable
Listed in EU database	No
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	Bulnesol exhibits stereoisomerism due to the presence of three defined stereogenic (chiral) centres in its structure (at positions 3, 3a, and 5 of the hydroazulene skeleton). This means multiple stereoisomers are theoretically possible, including diastereomers and enantiomers, though naturally occurring bulnesol from sources like guaiacwood oil is typically isolated as a specific stereoisomer with (+)-optical rotation. Additionally, bulnesol is a constitutional isomer of other sesquiterpene alcohols with the same formula such as guaiol (which shares the molecular formula but has a different carbon skeleton arrangement and connectivity, often co-occurring in the same essential oils).
Chemical formula	C₁₅H₂₆O
Canonical SMILES	CC1CCC2=C(CCC(CC12)C(C)(C)O)C
Isomeric SMILES	-
International Chemical Identifier key (InChIKey)	LGOFSGDSFQNIAT-UHFFFAOYSA-N
International Chemical Identifier (InChI)	InChI=1S/C15H26O/c1-10-5-7-12(15(3,4)16)9-14-11(2)6-8-13(10)14/h11-12,14,16H,5-9H2,1-4H3
2D structure diagram/image available?	Yes

General status

Biopesticide type		Insecticide; Antimicrobial; Repellent
Substance groups		Plant-derived substance; Bicyclic sesquiterpenoid alcohol
Minimum active substance purity		-
Known relevant impurities		-
Substance origin		Natural
Mode of action		The primary mode of action of bulnesol as a biopesticide is neurotoxicity, specifically through the inhibition of acetylcholinesterase (AChE). This leads to an accumulation of acetylcholine in the synaptic cleft, causing constant nerve stimulation, hyperexcitation, and eventual paralysis or death of the pest. It has been associated with the induction of oxidative stress in target organisms. This increases levels of reactive oxygen species (ROS) and nitric oxide, causing lipid peroxidation and severe damage to cell membranes. Due to its hydrophobic nature, bulnesol can easily cross the lipid-rich membranes of insects and mites, facilitating rapid toxic action. Beyond direct toxicity, it acts as a behavioural deterrent by interfering with the gustatory and olfactory receptors of larvae and adult insects, leading to feeding cessation and starvation.
Substance source		A major constituent in guaiacwood oil and occurs in smaller amounts in other plant essential oils.
Uses		Crop protection; Public health
Target pests		Mites (Tetranychus urticae, Varroa destructor); Whiteflies; Aphids; Thrips; Leafminers; Nematodes (Meloidogyne spp.).
Target host		Most horticulture & greenhouse crops including tomatoes, peppers and cucumbers; Fruit trees; Ornamentals; Residential & public spaces
Farming system suitability		Suitable for all farming systems where approved for use in that country
CAS RN		22451-73-6
EC number		-
CIPAC number		-
US EPA chemical code		-
PubChem CID		90785
Molecular mass		222.37
PIN (Preferred Identification Name)		-
IUPAC name		2-(3,8-dimethyl-1,2,3,3a,4,5,6,7-octahydroazulen-5-yl)propan-2-ol
CAS name		5-azulenemethanol, 1,2,3,3a,4,5,6,7-octahydro-α,α,3,8-tetramethyl-, (3S,3aS,5R)-
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)		Not applicable
Examples of recorded resistance		-
Physical state		Typically appears as a colourless to pale yellow viscous liquid or semi-solid that solidifies at room temperature
Related substances & organisms		guaiacwood oil

Commercial

Property	Value
Availability status	Current
Introduction & key dates	-
Example manufacturers & suppliers of products using this active now or historically	Ecoflora Agro SAS Columbia
Example products using this active	Bulnesol is supplied commercially either within guaiacwood oil or as a high-purity fraction/extract for specialised uses, including research or niche biopesticide formulations.
Formulation and application details	Applied at low aqueous concentrations as foliar sprays or soil drenches
Commercial production	The commercial production process of bulnesol involves harvesting mature trees or utilising wood residues/sawdust from sustainable forestry or land clearance activities. The next step is grinding the extremely dense heartwood into fine sawdust or chips. Steam distillation of the ground wood/sawdust mixture is then used to yield a viscous, yellowish to greenish semi-solid oil. In some cases, the oil is diluted (e.g. in fractionated coconut oil) for easier handling and pouring, as pure guaiacwood oil is thick and paste-like.
Impact on climate of production and use	Data for specific plant oils is scarce. However, from publicly available data the carbon footprint of plant oils has been estimated at between 1.0 and 4.0 kg CO₂e per kg of oil. This depends on the plant oil content, agricultural practices and processing methods used.

ENVIRONMENTAL FATE

Property		Value	Source; quality score; and other information	Interpretation
Solubility - In water at 20 °C at pH 7 (mg l⁻¹)		7.1	Q3 Q = Miscellaneous data from online sources 3 = Unverified data of known source	Low
Solubility - In organic solvents at 20 °C (mg l⁻¹)		-	-	-
Melting point (°C)		40	Q3 Q = Miscellaneous data from online sources 3 = Unverified data of known source	-
Boiling point (°C)		-	-	-
Degradation point (°C)		-	-	-
Flashpoint (°C)		-	-	-
Octanol-water partition coefficient at pH 7, 20 °C	P	7.94 X 1004	Calculated	-
	Log P	4.9	Q3 Q = Miscellaneous data from online sources 3 = Unverified data of known source	High
Fat solubility of residues	Solubility	-	-	-
	Data type	-	-	-
Density (g ml⁻¹)		0.939	Q3 Q = Miscellaneous data from online sources 3 = Unverified data of known source	-
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)		-	-	-
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)		-	-	-
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)	-	-	-
	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	-
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)		-	-	-
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)		-	-	-
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)		-	-	-
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	No data	No data for acute and chronic mammals
Birds	No data	No data for 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	No data	No data for contact and oral honeybees
Arthropods	No data	No data for parasitic wasps and predatory mites
Fish	No data	No data for temperate acute and chronic fish
Aquatic invertebrates	No data	No data for temperate acute and chronic aquatic invertebrates
Aquatic plants	No data	No data for 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)		Low (class I)	-	-
Mammals - Acute oral LD₅₀ (mg kg⁻¹)		-	-	-
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)		-	-	-
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 ; E3 E = Unspecified genotoxicity type (miscellaneous data source) 3 = Negative No data found Reproduction / development effects Acetyl cholinesterase inhibitor Neurotoxicant No data found No data found No data found Respiratory tract irritant Skin irritant Skin sensitiser No data found XNo, known not to cause a problem XNo, known not to cause a problem Eye irritant Phototoxicant   XNo, known not to cause a problem No data found
General human health issues		Generally considered low toxicity for humans at standard exposure levels

Handling issues

Property	Value and interpretation
General	No information available
CLP classification 2013	-
WHO Classification	-
UN Number	-
Waste disposal & packaging	-
Shelf-life, storage, stability and reactivity	-

TRANSLATIONS

Language	Name
English	bulnesol
French	-
German	-
Danish	-
Italian	-
Spanish	-
Greek	-
Polish	-
Swedish	-
Hungarian	-
Dutch	-
Norwegian	-

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Record last updated:	23/02/2026
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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