UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON, D.C. 20460 

JUN 1 5 2015 

MEMORANDUM 

OFFICE OF CHEMICAL SAFETY 

AND POLLUTION PREVENTION 

SUBJECT: BEAD Chemical Profile for Registration Review: Chlorophacinone (067707) 

.,}' 

FROM: Colwell Cook, Biologist eW 

Biological Analysis Branch 

THRU: 

TO: 

Cynthia 

Science Information 

Doucoure, Environmental 

and Analysis Branch 

Protection Specialist {!. ~ 

Elizabeth Hill, Economist 

Economic Analysis Branch 

Biological and Economic Analysis Division (7503P) 

Amet Jones, Chief 

Biological Analysis Branc 

Diann Sims, Chief 

Science Information and Analysis Branch 

Timothy Kiely, Chief ~ \M.;iJ Economic Analysis Branch 

Biological and Economic Anal ts Division 503P) 

Russell Wasem, Chemical Review Manager 

Risk Management and Implementation Branch I 

Pesticide Re-evaluation Division (7508P) 

Product Review Panel date: May 27,2015 

Page 1 of 5 
SUMMARY 

Chlorophacinone was registered in 1971 as a vertebrate control agent. Based on available USDA 

NASS survey data, chlorophacinone is reported to be used to treat rodents in apples and cherries 

in very small quantities. The average percent crop treated (PCT) for both crops is <2.5% and the 

average annual pounds a.i. applied is <500. 

INTRODUCTION 

The purpose of this document is to convey usage information and a broad overview of the pest 

management roles of pesticides that are beginning to undergo registration review. The 

anticipated audience consists of the team of EPA staff currently evaluating the registration status 

of chlorophacinone and the general public. This document builds upon the data BEAD provides 

in the Label Use Information System (LUIS) reports and the Screening Level Usage Analysis 

(SLUA) to Registration Review teams. The document is based on information and data available 

to BEAD as of April 2015 

HISTORY OF BEAD ASSESSMENTS FOR CHLOROPHACINONE 

BEAD prepared a Screening Level Usage Analysis (SLUA) in April 2015 that contained 

agricultural usage information on the predominant uses of chlorophacinone during the 2004-

2013 time frame. Chlorophacinone was reported to be used on two crops: apples and cherries. 

The average percent crop treated (PCT) for both crops was <2.5% and the average pounds a.i. 

applied annually for both crops was <500 lbs a.i. 

BEAD conducted an analysis of rodenticide bait use in 2006 (Chiri, 2006) which examined nine 

rodenticide products, including chlorophacinone. Chlorophacinone is considered a firstgeneration anticoagulant for use against commensal rats and mice and other rodents. This 

analysis concluded that rodenticides are necessary for managing rodents, which are a significant 

public health risk and are capable of causing significant economic damage. It also concluded 

that rodenticide active ingredients, in general, are interchangeable and can be considered 

alternatives to one another. 

In 2010, BEAD conducted a benefits assessment for the use of chlorophacinone to control blacktailed prairie dogs (Chiri, et al., 2010). This assessment was done in response to a petition 

submitted by multiple environmental groups over concerns of secondary impacts to non-target 

species. BEAD found that the principle benefits of chlorophacinone baits to users was that these 

baits significantly reduced the time and labor required to effectively control black-tail prairie 

dogs. That is, the use does not result in bait aversion and does not require pre-baiting, which is 

necessary for alternatives that deliver a sublethal dose. It also reduces post-application 

requirements for disposal of prairie dogs. 

Page 2 of 5 
To date, BEAD has not reviewed any Section 18 Emergency Exemption Requests for the use of 

chlorophacinone. However, this should not be interpreted as a lack of benefits associated with 

the chemical. 

COMMON FORMULATIONS AND APPLICATION METHODS 

Chlorophacinone is formulated as pelletized and granular (hulled rolled oat) baits, and a 

powdered formulation. These are applied via aircraft, funnels, granule applicators, hand bulb 

dusters, mechanical burrow builders, dippers, and trap/bait stations. 

USE SITES 

Agricultural Use Sites: 

Chlorophacinone is registered for use in alfalfa, artichoke, barley, fruit tree orchards (pome and 

stone fruit) crops, nurseries, oats, pastures/rangelands, nurseries, Christmas tree plantations, and 

tree and forestry plantations. 

Non-Agricultural Use Sites: 

Chlorophacinone is registered for use in and around animal burrows and buildings (agricultural, 

public, industrial/commercial, homes, and food processing facilities) and transport vehicles 

(ships, trains, and aircraft) and in noncrop areas (fence lines, gullies, ditches, railroad rights-ofway, etc.), lawns/turf, golf courses, and ornamental flower and shrub gardens. 

CHLOROPHACINONE USAGE 

According to USDA NASS survey data, chlorophacinone was reportedly used in apple and 

cherry orchards in relatively low quantities; total acres treated, pounds applied, and average AI 

rates of application as shown in Table 1 below. Chlorophacinone was also reported to be used 

by consumers in very low quantities in 2009 as shown in Table 2 below. 

T a e bl 1 A . gncu . tura lU se o fChl h . oropJ acmone, 2007 an d 2009 

Site Year Acres Treated Lbs A.I. Avg AI. No. of 

Applied Rate Apps 

Apples 2007 5,760 5.76 0.001 1.1 

Cherries 2009 1,176.5 100 0.085 1.1 

Source: USDA NASS Agricultural Chemical Usage Reports, 2007 and 2009 

Page 3 of 5 
T a e bl 2 N A on- ~ogncu . tura lU se o 

Sector Year 

Consumer 2009 

Markets for 

Pesticides & 2011 

Fertilizers 

Source: Kline & Company, 2009 

Proprietary Data, 20 I I 

fChl h . orop acmone, 2009 an d 2011 

Lbs A.I. Applied % ofTotal 

Rodenticides 

48 0.3 

52 0.3 

BEAD also reviewed California data to determine if use of 1st generation anticoagulant 

rodenticides is increasing. It appears that, based on California Department of Pesticide 

Regulations (DPR) data from 2009-2013, chlorophacinone use increased slightly in 2011, 

followed by a slight decrease at the end of the period, as shown in Table 3 below. 

T a e bl 3 Chi h . orop1 acmone u . c l"f sage m a I ornia: A .g an dN on-ag 

Chemical Pounds A.I. Applied 

2009 2010 2011 2012 2013 

Chlorophacinone 12.95 10.95 28.6 19.88 13.59 .. Source: California DPR, PestiCide Use Reportmg, Summary Data, 2009-2013 

BIOLOGICAL ASPECTS RELEVANT TO CHLOROPHACINONE 

Chlorophacinone is considered to be a first generation rodenticide, belonging to the indandione 

class of anticoagulants. These compounds must be ingested and require several feedings for the 

rodent to ingest a toxic dose. These chemicals interfere with normal blood-clotting mechanisms 

resulting in capillary damage and hemorrhage. 

ROLE OF CHLOROPHACINONE IN PEST MANAGEMENT 

Many rodents are public health pests, such as Norway rats, roof rats, and house mice. These 

animals carry diseases, impacting human health as well as domestic animals. Rodents also 

impact agriculture. Many will feed directly on crops, both in the field and after harvest. In 

addition their gnawing can directly damage farm equipment and structures. Their burrowing 

activities also impact agriculture and other human activities. 

Chlorophacinone is a critical component of a rodent management strategy. For a homeowner, 

along with sanitation and exclusion, chlorophacinone may be used in bait traps. 

Chlorophacinone, in addition to diphacinone, is an important component of control for prairie 

dogs, ground squirrels, and other rodent pests in agriculture, especially in orchards, vineyards, 

and rangelands. Managers of forested areas and parks use these first generation anticoagulant 

Page 4 of 5 
rodenticides to control populations of rodents to reduce spread of diseases (e.g. Hantavirus) and 

maintain the grounds. 

INFORMATION THAT MAY BE USEFUL FOR BEAD'S FUTURE WORK ON 

CHLOROPHACINONE 

For future BEAD assessments, the following information would be helpful: usage data for nonagricultural sites (lbs a.i. applied, typical number of applications per year, maximum dose per 

year), and more detail about how chlorophacinone is used in agriculture to control vertebrate 

pests. 

REFERENCES 

California Department of Pesticide Regulation, Pesticide Use Reporting, Summary Data, 2009-

2013 

Chiri, A. 2006. Analysis of Rodenticide Bait Use. U.S. Environmental Protection Agency, 

Office of Chemical Safety and Pollution Prevention. 

Chiri, A., C. Cook, T. Wyatt, and E. Hill. 2010. Benefits Assessment for Chlorophacinone 

(Rozol) Use to Control Black-Tailed Prarie Dogs. U.S. Environmental Protection Agency, 

Office of Chemical Safety and Pollution Prevention. 

EPA Screening Level Usage Analysis (SLUA), April 2015 

Kline & Company, Inc., 2009 

Proprietary Data, 2011 

USDA NASS, Agricultural Chemical Usage Reports, 2007 and 2009 

Page 5 of 5