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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C.  20460

OFFICE OF              

PREVENTION, PESTICIDES

AND TOXIC SUBSTANCES 

MEMORANDUM

DATE:  	December 14, 2010

SUBJECT:	Preliminary of Product Chemistry, Toxicity and Environmental
Effects in Support of the Registration Review of (Z)-9-tricosene
(Muscalure)  

				Registration Review Case #: 	4112

Chemical Class: 				Biochemical

PC Code: 					103201

  FROM:	Manying Xue, Chemist   

Biochemical Pesticides Branch

Biopesticides & Pollution Prevention Division (7511P)

		

TO:	John Fournier, Regulatory Action Leader

Biochemical Pesticides Branch

Biopesticides & Pollution Prevention Division (7511P)

Action Requested

The following is a preliminary product chemistry, human health
assessment and environmental effect for the biopesticide,
(Z)-9-tricosene (Muscalure) in support of the development of the
Registration Review Work Plan.  

Background

(Z)-9-tricosene (a.k.a. Muscalure Fly Attractant or cis-9-tricosene) is
an attractant pheromone for house flies (Musca domestica), stable flies
(Stomoxys calcitrans), eye gnats, and horse flies.  (Z)-9-tricosene was
classified as a biochemical pest control agent on May 5, 1989 because,
even though chemically synthesized, it is identical to the sex pheromone
of the female house fly.  It is used as a pest insect attractant in
traps and, as such, has a non-toxic mode of action.  

Pesticide products containing (Z)-9-tricosene were first registered in
1975 for use in fly bait products to disrupt fly mating. In 1994, the
Agency published a Reregistration Eligibility Document (RED) and a RED
Fact Sheet for (Z)-9-tricosene.Products containing this active
ingredient (a.i.) are used in a number of places where fly control is
considered necessary, including food/feed handling establishments and
livestock premises.  There are no established tolerances or tolerance
exemptions for (Z)-9-tricosene.

Conclusions:

1.	The existing data of product chemistry, toxicity and environmental
effects for the TGAI of (Z)-9-tricosene (Muscalure) have been evaluated.
 No data deficiencies have been found for this registration review
action. 

2.	However, the registrant needs to submit a petition for tolerance
exemption, because the end use products are used around food and feed
handling. Therefore, the products are considered as food use. In
addition, the products are not covered by tolerance exemption of
arthropod pheromones under 40 CFR 180.1124. The Agency will re-evaluate
the risk for this food use. The petition will require additional data
based on 40 CFR 158.2030, 158.2040, 158.2050, & 158.2060.

Product Analysis (40 CFR 158.2030)

	

The Agency has conducted a review of the available product chemistry
data and information for the a.i., (Z)-9-tricosene. Product chemistry
information for (Z)-9-tricosene, provided by the registrants, produces a
complete product chemistry data set.  

The chemical identity data for (Z)-9-tricosene is summarized in Table 1.
Currently, there are four technical grade active
ingredient/manufacturing-use products (TGAI/MUP) registered by the
Agency that contain this active ingredient. The most recently
EPA-registered TGAI product, Z-9 Tricosene Technical (EPA Reg. No.
57978-7) was registered on September 30, 1998, and is 70% pure.  All of
the registered TGAI products are labeled for the manufacturing of
end-use products for use in bait stations, insecticide strips, and
granules for the control of house flies, stable flies, and blow flies. 
In accordance with 40CFR 152.25(b), a technical grade (Z)-9-tricosene
product may be used in traps and lures without further registration
requirements when it is the only active ingredient. Physical and
chemical properties are shown in Table 2. 

Table 1.  Muscalure Chemical Identity

Common Name	Muscalure or muscamone

Chemical Name	(Z)-9-tricosene or cis-9-tricosene

Technical Trade Names	Muscalure, Technical Tricosene, Technical
Muscalure, Z-9-Tricosene Technical Pheromone, Z-9-Tricosene Technical

Molecular Weight	322.62 g/mol

PC Code	103201

CAS Registry Number	27519-02-4

Empirical Formula	CH3(CH2)12CH=CH(CH2)7CH3

Registration Review Case Number	4112

Chemical Structure	



TABLE 2.  Physical and Chemical Properties for (Z)-9-tricosene
(Muscalure)



Guideline Reference No./Property	

Description of Result	

Methods



830.6302	Color	Colorless	Visual inspection



830.6303	Physical State	liquid 	Visual inspection 



830.6304	Odor	Faint waxy odor	factory inspection



830.6313	Stability	Stable to heat and light

	

830.6314	Oxidation/Reduction: 

Chemical Incompatibility	N/A

	

830.6315	Flammability	Flash point 113°C	Pensky-Mertens closed cup (ASTM
D93)



830.6316	Explodability	N/A, product does not contain explosive
ingredients

	

830.6317	Storage Stability	No change in 2 years when stored in a cool,
dark place.

	

830.6319	Miscibility	N/A, the product is not intended to be mixed with
petroleum solvents.

	

830.6320	Corrosion Characteristics	Not corrosive 

	

830.6321	Dielectric Breakdown Voltage	N/A

	

830.7000	pH	N/A	CIPAC MT-75



830.7050	UV/Visible Absorption	250nm

	

830.7100	Viscosity	3-4 cps@25°C	ASTM D445/D446



830.7200	Melting Range	> 0°C

	

830.7220	Boiling Range	378°C

	

830.7300	Density/Relative Density/Bulk Density	0.807 @25°C	CIPAC MT-3,
ASTM D891-95, OECD Guideline No. 109



830.7550	Partition Coefficient	Not Submitted

	

830.7840	Solubility	Insoluble in Water; slightly soluble in alcohol;
miscible with aliphatic and aromatic hydrocarbons.

	

830.7950	Vapor Pressure	0.000035 mm Hg at 27° C

	a Data from MRID 40883003.

Human Health Risk Assessment Status (40 CFR 158.2050)

Acute toxicity studies for (Z)-9-tricosene are available in the Agency
data base to fulfill the acute dermal toxicity requirement. There are
two sets acute toxicity studies were performed for acute oral toxicity,
acute dermal toxicity, acute inhalation toxicity, acute eye irritation,
acute dermal irritation and skin sensitization. The results indicate
toxicity category IV for acute oral toxicity, acute dermal toxicity,
acute inhalation toxicity and acute dermal irritation; and toxicity
category III for acute eye irritation. (Z)-9-tricosene is not a dermal
sensitizer (see Table 3).

Since this active ingredient is not related to a known mutagen and does
not belong to a class of chemical compounds containing known mutagens,
and since the use is not likely to result in significant human exposure,
this requirement is waived.  Requirements for immune response and
subchronic toxicity were waived because the pheromone is applied or
contained in a solid substance or matrix. Currently registered TGAIs
have human health toxicity data on file, which is summarized in Table 3.


Table 3.  Human Health Toxicity for (Z)-9-tricosene

Study Type/Guideline	

LD50/LC50/Results	

Toxicity Category	Source



Acute Oral Toxicity/OCSPP 870.1100	Acute oral LD50 > 5,000 mg/kg (rat)
IV	41783601

42077301



Acute Dermal Toxicity/OCSPP 870.1200	Acute dermal LD50 > 2,000 mg/kg
(rabbit)	IV	41783602

42077302



Acute Inhalation Toxicity/OCSPP 870.1300	Acute inhalation LC50 > 5 mg/L
(rat)	IV	42176701

42052802



Acute Eye Irritation/OCSPP 870.2400	Slight irritant (rabbit)	III
41783603

41785401



Acute Dermal Irritation/OCSPP 870.2500	Slight irritant (rabbit)	IV
41783604

41785402

Skin Sensitization/OCSPP 870.2600	Moderate sensitizer (guinea pig)	not
dermal sensitizer

	42052801

41783605



90-day Oral/ OCSPP 870.3100	Waived 

-

90-day Dermal – rat/OCSPP 870.3250	Waived

-



90-day Inhalation – rat/OCSPP 870.3465	Waived

-



Prenatal Developmental/OCSPP 870.3700	Waived

-

Mutagenicity:

Bacterial Reverse Mutation Test (Ames)/OCSPP 870.5100	Waived

-

Mutagenicity:

In vitro Mammalian Cell Assay (mouse lymphoma)/OCSPP 870.5300	Waived

-

1 highest dose tested

Environmental Fate and Ecological Risk Assessment Status (40 CFR
158.2060)

Avian Toxicity Studies 

Avian acute oral toxicity studies and avian subacute dietary toxicity
studies demonstrate that (Z)-9-tricosene is practically non-toxic to
bobwhite quail and mallard duck.  There was reproductive impairment in
mallard duck at 2.0ppm (TGAI), and 20 ppm (98.7% a.i.).  In one
additional study, no reproductive effects were observed at 0.10ppm.  No
reproductive effects were noted in bobwhite quail tested at up to 20.0
ppm with TGAI and 98.7% of (Z)-9-Tricosene, ai (see Table 4).

Table 4. Summary of Avian Toxicity for (Z)-9-tricosene

Guideline/Study Type	Results	Classification	MRID No.

850.2100

Acute Oral

Bobwhite quail

(Colinus virginianus)	LD50>2,000 mg/kg	Practically non-toxic	41785403



850.2200

Acute Dietary

Bobwhite quail

(Colinus virginianus)	LC50>5,000 ppm; NOEC = 5,000 ppm	Practically
non-toxic	41785404



Aquatic Toxicity Studies

Freshwater fish acute toxicity and freshwater aquatic invertebrates
acute toxicity studies using the TGAI are used to establish the toxicity
of (Z)-9-tricosene to aquatic species.  Results of these studies are
summarized below in Table 5.  (Z)-9-tricosene has been shown to be
practically non-toxic to fish and highly toxic to aquatic invertebrates
based on the available data where toxicity values are LC50>1,000ppm in
Oncorhynchus mykiss (fish) and LC50 = 1.08 ppm in Daphnia magna (aquatic
invertebrate).  

Table 5. Summary of Aquatic Toxicity Studies for (Z)-9-tricosene

Guideline/Study Type	Results	Classification	MRID No.

850.1075

Rainbow trout

(Oncorhynchus mykiss)	96-hr LC50 >5,000 ppm	Practically non-toxic
00232388

00232017

850.1010

Water flea

(Daphnia magna)	48-hr LC50 = 1.08 ppm

	Highly toxic	00232388



Risk to Threatened and Endangered Species 

	

Based on the specific use patterns, the Agency does not anticipate the
need to require additional data for (Z)-9-tricosene. The active
ingredient has very low mammalian toxicity based on submitted acute
toxicology data.  Avian acute oral toxicity studies and avian subacute
dietary toxicity studies demonstrate that (Z)-9-tricosene is practically
non-toxic to bobwhite quail and mallard duck.  

The active ingredient was shown to cause reproductive impairment in
mallard duck at 2.0 ppm and 20 ppm and is also highly toxic to water
fleas (Daphnia magna).  For products which contain impregnated materials
and solid matrix forms (bait stations and strips), exposure to
terrestrial and aquatic species will be minimal.  For products
formulated as crystals or granules, minimal acute effects to terrestrial
species can be expected.  To mitigate the avian reproduction toxicity
concern for broadcast products and the accessibility to birds, the
Agency is requiring registrants to modify their products in a manner
that would significantly reduce the exposure potential to birds, such as
bait stations. There no information available for a risk assessment to
supports a complete endangered species determination for
(Z)-9-tricosene.  

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