UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON, D.C. 20460 

JAN 16 2013 

OFFICE OF CHEMICAL SAFETY 

AND POLLUTION PREVENTION 

MEMORANDUM 

SUBJECT: 

FROM: 

THRU: 

TO: 

BEAD Chemical Profile for Registration Review: Niclosamide (077401) 

Colwell Cook, Entomologist~~ Biological Analysis Branch 

Rafael 

Science 

Prieto, 

Information 

Environmental 

and Analysis 

Protection 

Branch 

Specialisy a v7 hA '""'-J { · -P ~ 

John Faulkner, Economist \J...J All 

Economic Analysis Branch ~, v' ~ 

~iological and Economic011 Anl sis Division (7503P) 

Arnet Jones, Chief 

Biological Analysis Branc 

Diann Sims, Chief J{1 "? ~ Lr~~r­ Science Information and Analysis Branch 

Timothy Kiely, Chief !,\- W\_ \- .... 0 

Economic Analysis Branch \.} ) 'fA-() 

Biological and Economic Analysis Division (7503P) 

Kelly Ballard, Chemical Review Manager 

Risk Management and Implementation Branch 1 

Pesticide Re-evaluation Division (7508P) 

Product Review Panel date: November 28,2012 

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 niclosamide, and eventually the general public. This document builds upon the data already 

provided in the usage and label use data packages that are also provided to Registration Review 

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teams by BEAD. The document is based on information and data available to BEAD as of 

November 19, 2012. 

Niclosamide is a critically important pesticide. It is a chloronitrophenol derivative that is used to 

kill Atlantic sea lamprey larvae, Petromyzon marinus, in combination with another lampricide, 3-

trifluoromethyl-4-nitrophenol, TFM (EPA 1999; USGS 2012 Focus Meeting). These invasive 

pests are aggressive parasites offish and have reduced the populations of native fish in all of the 

Great Lakes (University of Wisconsin Sea Grant Institute 2002). Sea lampreys are native to the 

Atlantic Ocean. They are an ocean, eel-like, fish that spawn in fresh water. They were found in 

Lake Ontario in 1835, and introduced into Lake Erie in 1921, probably through the Weiland Canal 

(USDA 2011 ). Niclosamide targets the mitochondria and uncouples oxidative phosphorylation, 

which results in the lampreys not being able to meet their energy demands (Bayluscide Label). 

These products are manufactured by and for the U.S. Fish and Wildlife Services. 

HISTORY OF BEAD ASSESSMENTS FOR NICLOSAMIDE 

BEAD reviewed an emergency exemption from Mississippi (EPA, 2000) requesting the use of 

niclosamide to control the ram's hom snail, genus Planorbis, which is the intermediate host of a 

trematode that infects many species offish. BEAD concluded that catfish farmers would suffer a 

significant economic loss with the pest, since there were no alternatives for control. It appears 

that this could have been an ongoing problem. In 2004, niclosamide was registered for use against 

freshwater snails in catfish and fish ponds, when the ponds do not contain fish. 

FORMULATIONS 

Niclosamide is formulated as a granular, wettable powder and emulsifiable concentrate. 

USE SITES 

Agricultural Use Sites 

Niclosamide is used on fish and catfish ponds as a water treatment, when no fish are present. 

Non-Agricultural Use Sites 

Niclosamide is used only for aquatic sites [seines, potable water, irrigation supply systems, ponds 

(ornamental and fish), impounded water, lakes and ponds], and water treatment for rivers and 

streams to control sea lamprey. Granular niclosamide is used in lentic areas where the larvae live 

in still waters. It is sprayed over infested area, sinks to bottom, and dissolves. Larvae infest some 

lentic areas associated with streams (EPA, 2012). 

USAGE 

Available data from proprietary data, USDA/NASS, and California Department of Pesticide 

Regulation databases did not show any uses for this chemical on either agricultural crops or nonagricultural sites. In 2011 nine lentic areas were treated in the U.S. and seventeen areas were 

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treated in Canada. In 2010 and 2011 over 2000 acres were treated in the St. Marys River. The 

largest lentic areas are interconnecting waterways (St. Marys, St. Clair Rivers, which border 

Michigan and Canada) (EPA, 2012). 

BIOLOGICAL ASPECTS 

The sea lamprey is an invasive species introduced into the Great Lakes. This blood-sucking fish 

has devastated the native fishes of the Great Lakes (University of Wisconsin Sea Grant Institute 

2002). Niclosamide, in conjunction with TFM, is the lampricide used to control sea lamprey 

larvae in tributaries to the Great Lakes, the Finger Lakes and Lake Champlain (EPA 1999). These 

are the only products available to control sea lampreys. 

CONCLUSION 

The sea lamprey is an invasive, aggressive pest that has greatly impacted the native fish of the 

Great Lakes, and it is critical to control. Niclosamide is a major lampricide, used in conjunction 

with TFM, to control this significant pest; it is highly restricted to the tributaries of the Great 

Lakes; and can only be purchased and applied by certified applicators of the U.S. Fish and Wildlife 

Services, Fisheries and Oceans Canada, and provincial and state fish and game employees. In 

addition, there are no alternatives to control freshwater snails in fish ponds. 

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

NICLOSAMIDE 

The U.S. Fish and Wildlife Services will provide usage data to the Agency when it becomes 

available. BEAD will also need data regarding the use of this chemical in snail control. 

REFERENCES: 

EPA. 1999. Niclosamide Reregistration Eligibility Document (RED). Available at: 

http://www.epa.gov/oppsrrd1!REDs/3082red.pdf. Accessed November 19, 2012. 

EPA, 2000. BEAD Review of Documentation in Support of an Emergency Exemption for the Use of 

Niclosamide (Bayluscide®) in Catfish Ponds to Control the Rams Hom Snail (00-MS-0021), September 13. 

EPA, 2012. Registration Review Focus Meeting with Fish and Wildlife Service, U.S. Geological Survey, 

and Great Lakes Fishery Commission. November 5, 2012 

NYS Department of Environmental Conservation. 2011. Found at: 

http://www.dec.ny.gov/animals/7240.html. Accessed: August 6, 2009. 

USDA. 2011. Sea lamprey. Sea lamprey control. Found at: 

http://www.invasivespeciesinfo.gov/aquatics/lamprey.shtml. Accessed: August 6, 2009. 

University of Wisconsin Sea Grant Institute. 2002. Sea lamprey. Found at: 

http://seagrant.wisc.edu/greatlakesfish/sealamprey.html. Accessed: August 6, 2009. 

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