Muscalure

Muscalure	Last updated: 25/08/2025
(Also known as: Z-9-tricosene; (Z)-9-tricosene; cis-tricos-9-ene; muscamone; house fly sex pheromone)

SUMMARY

Non-toxic to humans. Major environmental pathways include volatilisation and microbial degradation. Highly toxic to aquatic invertebrates but practically non-toxic to freshwater fish however minimal exposure would be expected. Not expected to be harmful to beneficial insects.

Hazard 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. These hazard alerts do not take account of usage patterns or exposure, thus do not represent risk.

Environmental fate	Ecotoxicity	Human health
Environmental fate Moderate alert: Drainflow: Moderately mobile Warning: Significant data are missing	Ecotoxicity Moderate alert: Daphnia acute ecotoxicity: Moderate	Human health Low alert

GENERAL INFORMATION

Description

An insect sex pheromone of the housefly used to trap flies in agricultural and domestic situations

Example pests controlled

Flies

Example applications

Animal houses; Public and domestic buildings

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 plant protection agent

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status

Not approved

Dossier rapporteur/co-rapporteur

Austria

Date EC 1107/2009 inclusion expires

Not applicable

EU Candidate for substitution (CfS)

Not applicable

Listed in EU database

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

Known to be also used in the following countries

Australia, USA

Chemical structure

Isomerism

Muscalure exhibits geometrical isomerism due to the presence of a carbon-carbon double bond at the 9th position of a long hydrocarbon chain. This double bond restricts rotation, allowing for two possible configurations: cis (Z) and trans (E). Muscalure is specifically the cis-isomer, where the substituents on either side of the double bond are on the same side.

Chemical formula

C₂₃H₄₆

Canonical SMILES

CCCCCCCCCCCCCC=CCCCCCCCC

Isomeric SMILES

CCCCCCCCCCCCC/C=C\CCCCCCCC

International Chemical Identifier key (InChIKey)

IGOWHGRNPLFNDJ-ZPHPHTNESA-N

International Chemical Identifier (InChI)

InChI=1S/C23H46/c1-3-5-7-9-11-13-15-17-19-21-23-22-20-18-16-14-12-10-8-6-4-2/h17,19H,3-16,18,20-23H2,1-2H3/b19-17-

2D structure diagram/image available?

Yes

General status

Biopesticide type

Insecticide; Semiochemical

Substance groups

Pheromone

Minimum active substance purity

Known relevant impurities

Substance origin

Natural

Mode of action

As male populations are reduced, breeding cycle is disrupted resulting in less egg production and lower populations

Substance source

Substance is secreted by female house flies (Musca domestica)

Uses

Animal welfare; Public health

Target pests

Flies

Target host

Animal houses; Public and domestic buildings

Farming system suitability

CAS RN

27519-02-4

EC number

248-505-7

CIPAC number

None allocated

US EPA chemical code

103201

PubChem CID

Molecular mass

322.6

PIN (Preferred Identification Name)

IUPAC name

(Z)-tricos-9-ene

CAS name

(9Z)-9-tricosene

Forever chemical

Other status information

Relevant Environmental Water Quality Standards

Herbicide Resistance Class (HRAC MoA class)

Not applicable

Herbicide Resistance Class (WSSA MoA class)

Not applicable

Insecticide Resistance Class (IRAC MoA class)

UNM

Fungicide Resistance Class (FRAC MOA class)

Not applicable

Examples of recorded resistance

Physical state

Colourless to amber oil

Related substances & organisms

imidacloprid

Commercial

Property

Value

Availability status

Current

Introduction & key dates

1971, first isolated; 1975, introduced USA

Example manufacturers & suppliers of products using this active now or historically

Bayer Environmental Science
Control Solutions
Troy Biosciences Inc, USA

Example products using this active

Maxforce Fly Spot bait
Bonanza Fly bait
Stimukil Fly Bait

Formulation and application details

Used in traps, sticky paper and dispensers, product may include rapid knockdown insecticide

Commercial production

Muscalure is commercially produced through chemical synthesis, typically starting from long-chain fatty acids or alkenes. The process involves constructing a 23-carbon chain with a cis double bond at the 9th position, which is crucial for its biological activity as a sex pheromone in houseflies. One common route includes olefin metathesis or Wittig reactions to introduce the double bond in the correct configuration. The synthesis is carefully controlled to ensure high purity and stereoselectivity, as only the (Z)-isomer is biologically active.

Impact on climate of production and use

While exact CO₂e values are not published for specific pheromones, some general information is available. The PHERA reported that biotechnological production (e.g. yeast fermentation) of pheromones can reduce GHG emissions by up to 90% compared to traditional chemical synthesis and GHG emissions are typically in the 5 to 10 kg CO₂e per kg of pheromone produced. Other sources suggest that small scale pheromone synthesis typically has emissions in the range 1 – 3 kg CO₂e per kg of pheromone produced.

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

Solubility - In water at 20 °C (mg l⁻¹)

0.000004

Low

Solubility - In organic solvents at 20 °C (mg l⁻¹)

Melting point (°C)

Boiling point (°C)

378

Degradation point (°C)

Flashpoint (°C)

113

(closed cup)

Octanol-water partition coefficient at pH 7, 20 °C

1.23 X 10⁰⁴

Calculated

Log P

4.09

High

Fat solubility of residues

Solubility

Data type

Density (g ml⁻¹)

0.807

Dissociation constant pKa) at 25 °C

Vapour pressure at 20 °C (mPa)

0.064

Low volatility

Henry's law constant at 25 °C (Pa m³ mol⁻¹)

5.30 X 10^-06

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)

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

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

K_d (mL g⁻¹)

Moderately mobile

K_oc (mL g⁻¹)

180

Notes and range

Best available data

Freundlich

K_f (mL g⁻¹)

K_foc (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)

> 10000

Rat

Low

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)

> 4640

Anas platyrhynchos

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)

> 1000

Eisenia foetida

Low

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)

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)

> 100

Expert judgement

Low

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)

> 1000

Oncorhynchus mykiss

Low

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)

1.08

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)

Algae - Chronic (growth rate, fresh; mg l⁻¹)

Mesocosm study data

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)

Low (class I)

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

> 10000

Rat

Low

Mammals - Dermal LD₅₀ (mg kg⁻¹ body weight)

2000

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

5.71

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

Health issues

Specific human health issues

Carcinogen

Genotoxic

Endocrine disruptor

; ; ; ;

No data found

Reproduction / development effects

Acetyl cholinesterase inhibitor

Neurotoxicant

No data found

Respiratory tract irritant

Skin irritant

Skin sensitiser

Eye irritant

Phototoxicant

No data found

General human health issues

No further information available

Handling issues

Property

Value and interpretation

General

No information available

CLP classification 2013

Health: H317

WHO Classification

Not listed (Not listed)

UN Number

Waste disposal & packaging

Shelf-life, storage, stability and reactivity

TRANSLATIONS

Language

Name

English

muscalure

French

muscalure

German

Muscalur

Danish

muscalur

Italian

muscalure

Spanish

muscalure

Greek

Polish

muskalur

Swedish

Hungarian

Dutch

Norwegian

Record last updated:	25/08/2025
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