UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON , D.C

. 20460 

### APR 2 82014

MEMORANDUM OFFICE OF CHEMICAL SAFETY AND POLLUTION PREVENTION

SUBJECT: BEAD Chemical Profile (BCP) for Registration Review: Dipropyl isocinchomeronate (PC Code 047201) FROM: David Brassard, Entomologist )

# ~**~** Biological Analysis Branch / SepehrHaddad, Environmental Protection Specialist ( 

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# ~~ Michelle Ranville, Economist 

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_ V\1\J 1 Biological and Economic Analysis Division ( 3P) TO: Molly Clayton, Chemical ReviewManager Risk Management and Implementation Branch III Pesticide Re-evaluation Division (7508P)

Peer Review Panel date: April 9, 2014

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### SUMMARY Dipropyl isocinchomeronate orMorpel® Repellent 326 (formerly MGK® Repellent 326) is never used as the sole active ingredient (a.i). Rather, it is used to expand the spectrum of repellency ofother formulation components. For instance, when found in products intended for use onhumans, dipropyl isocinchomeronate is always combined with DEET (N,N-diethyl-mtoluamide) and MGK® 264 at or below a concentration of2.5 percentby weight. Application methods include aerosols ortowelettes. For companion animal use, dipropyl isocinchomeronate is used at a concentration of4 percent for dip applications to dogs and cats and spray and towelettes products at a concentration from 0.2 to 1.0 percentthat are applied to horses (Vertellus Specialities, Inc., 2014). 

### INTRODUCTION The Biological and Economic Analysis Division (BEAD) Chemical Profile (BCP) provides an overview ofthe pest management roles and quantitative usage information for dipropyl isocinchomeronate. The BCP includes summaries ofprevious BEAD products and available public and/or private use and usage data for dipropyl isocinchomeronate to describe the role of this chemical inpestmanagement. Additional information on use is available inthe dipropyl isocinchomeronate LUIS Reports posted in the registrationreviewpublic docket. Information provided inthis BCP may be used by stakeholders (e.g., users and registrants), OPP risk assessors, OPP risk managers, and the general public during the Registration Reviewprocess of this pesticide. 

### USE SITES Agricultural Use Sites There are no agricultural uses for dipropyl isocinchomeronate. Non-agricultural Use Sites Registered non-agricultural use sites for dipropyl isocinchomeronate include indoor non-food (i.e., pet living/sleeping quarters) and residential use (i.e., repellents for humans and companion animals). 

### FORMULATIONS AND APPLICATION METHODS Application methods include aerosols and towelettes for humans, and dip and spray for applicationto cats and dogs, and spray and towelettes for horses. Application rates for insect repellentproducts are applied on an "as needed" basis for human and companion animal uses. 

### IDSTORY OFDIPROPYL ISOCINCHOMEROATE AND BEAD PRODUCTS Dipropyl isocinchomeronate was initially registered bythe USDA in 1957 as an insectrepellent for livestock. Tolerances were established for meat and milk and are found in 40 CFR 

### § Page2180.143. However, in 1993, McLaughlin Gormley and King Company, the technical registrant, elected to voluntarily cancel use onlivestock intended for slaughter, which resulted inthe chemical being limited to indoor non-food (i.e., pet living/sleeping quarters) and residential use (i.e., repellents for humans and companion animals).
A Reregistration Eligibility Decision (RED) document was issued in September 2003. As perthe RED, for the potential residential cancer risks associated with use ofdipropyl isocinchomeronate over a lifetime, the Agency limited production and distribution ofthe chemical for personal insect repellents to 20,000 lbs ofa.i. peryear. Additionally, the Agency limited and reduced the maximum concentration ofa.i. to 2.5 percent for end-use products containing dipropyl isocinchomeronate intended for use on humans. The Agency believedthat these steps were necessary to provide assurance that human exposure to dipropyl isocinchomeronate in the U.S. would not increase beyond current levels. Further, to limit potential overexposure to young children, no more than 3 applications per day ofdipropyl isocinchomeronate is allowed on children ages twelve and under (US EPA, 2003). A search ofthe BEAD database for previous BEAD products for dipropyl isocinchomeronate indicates that there are no records ofprior BEAD benefits assessments or Section 18 requests for this chemical. A lack ofSection 18 requests does not indicate the relative importance ofthe chemical. 

### USAGE Non-Agricultural Usage According to marketing data available atthe time the RED for this chemical was issued, the total amount ofdipropyl isocinchomeronate sold to customers withpesticide labels for use as "personal insectrepellents" was approximately 15,000 to 20,000 pounds (lbs) ofa.i. Whereas use on dogs/cats and horses averaged 2,100 and 14,000 lbs ofa.i., respectively (US EPA, 2003). However, in a personal communication, the sole registrant Vertellus Specialties, Inc. has provided more recentproduction data for the years 2010-2013 for dipropyl isocinchomeronate as shown in Table 1. Comparingthe more recent production datato the dataprovided previous to the RED shows that average annual domestic use priorto the red (26,000 lbs annually for years 1997-2001) has decreased tojustunder 7,000 lbs per year. The only available usage data from public orprivate databases was from USDA'sNational Agricultural Statistics Service. The Agricultural Chemical Usage survey showedthat 500 lbs a.i. were used on dairy cattle in 2006 at a rate of5.9 grams perheadperyear (USDA NASS, 2006). Atthis rate, approximately 38,000 head ofdairy cattle would be treated. The 2001 survey showed 1,900 lbs a.i. applied at a rate of 13.2 grams perheadperyear. At this rate, approximately 65,000 head ofcattle would be treated. The 1999 survey showed that 3,100 lbs a.i. were used onbeefcattle (USDANASS, 2000). This survey has not beenupdated.

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### 1. Total Production (lbs) and End Uses ofdipropyl isocinchomeronate, 1997-2001 and 2010-2013 Year 1997-2001 2010-2013 annual average annual average Total Production (lbs) Not Available 17,200 Volume Exported Outside ofUS NotAvailable 10,500 (lbs) Total Domestic Usage (lbs) 26,000 6,800 US Sales for Insect RepellentUse Not Available 4,800 onHumans (lbs) US Sales for Animal-only Insect Not Available 2,000 Repellent Uses (lbs) Sources: Vertellus Specialties, Inc. 2014; US EPA, 2003 BIOLOGICAL ASPECTS RELEVANT TO DIPROPYL ISOCINCHOMEROATE Dipropyl isocinchomeronate is added to insecticide products because ofits repellency properties and, in some cases, because ofits ability to extend the period ofrepellency ofother active ingredients. (Debboun et al., 2007) Dipropyl insosinchomeronate is formulated with a number of other active ingredients including diethyl toluamide (DEET), piperonyl butoxide, MGK 264, permethrin, and pyrethins in products labeled to repel fleas, ticks, flies, and other pests. ROLE OF DIPROPYL ISOCINCHOMEROATE IN PEST MANAGEMENT While there is limited information available for dipropyl isocinchomeroate, this chemical could play a role in public health protectionto the extentthat it improves the repellency ofproducts used to repel insects which vector Lyme disease, WestNile virus, and otherpathogens. Before the RED was issued in2003, the Agency requested a consultation withthe Centers for Disease Control and Prevention (CDC) regarding thepotential public health benefits ofdipropyl isocinchomeronate as an insectrepellent. CDC indicated its support for the registration ofthe chemical despite a lack ofdata on its efficacy. One dated study onhousefly 

### (Musca domestica) repellency found that dipropyl isocinchomeronate was the most effective chemical tested and more effective than DEET for repelling houseflies (Campbell, 1983). In addition to improving the repellency ofDEET products by preventing evaporation, dipropyl isocincheromeronate might increase repellency against stable flies, horse flies, and malaria mosquitoes (Strickman et al., 2009). The ongoing usage on cattle indicates that the chemical is an importanttool for fly control. DATA NEEDS The Agency currently does not have needed and important information on dipropyl isocinchomeronate. Obtaining the following information may improve future assessments conducted bythe Agency related to the use and importance ofthis chemical:

Page4Information onthe importance ofdipropyl isocinchomeronate for repellency

- Alternatives to dipropyl isocinchomeronate



### REFERENCES Campbell, M. M. 1983. A Test for Repellency to Non-biting Flies and A Comparison of Repellents UsingMusca domestica L. Pesticide Science 14: 199-212. Debboun, M., Frances, S. & Strickman, D. 2007. InsectRepellents: Principles, Methods, and Uses. New York: CRC Press. P. 376-377. Online: http:/ /www.crcpress.com/product/isbn/9780849371967. Accessed 31 March 2014. Strickman, D., Frances, S., & Debboun, M. 2009. Prevention of BugBites, Stings, andDisease. New York: OxfordUniversity Press. USDANASS. 2007. Agricultural Chemical Usage, 2006 Dairy Cattle and Dairy Facilities Summary. Online: http:/ /usdaO 1.librruy

.comell.edu/usda/current/ AgriChem UsDairv/ AgriChemUsDairy-05-23- 2007.pdf USDANASS. 2002. Agricultural Chemical Usage, 2001 Dairy Cattle and Dairy Facilities Summary. Online: http:/ /usdaO 1.librruy.comell.edu/usda/nass/ AgriChernUsDairy/ /2000s/2002/ AgriChemUsDai ry-05-29-2002.pdf USDANASS. 2000. Agricultural Chemical Usage, 1999 Cattle and Cattle Facilities. Online: http://usdaO1.library.comell.edu/usda/current/ AgChemUsCa/ AgChemUsCa-04-26-2000.pdf U.S. EPA, Reregistration Eligibility Decision for Dipropyl isocinchomeronate (MGK Repellent 326), 2003. Online: http://www.epa.gov/oppsrrd11REDs/mgl£ 326 red.pdf Vertellus Specialties, Inc. Personal communicationwith Beth Sullivan, ProductRegulatory Manager, February 24,2014.

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