UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON D.C., 20460 

MEMORANDUM 

SUBJECT: 

TO: 

FROM: 

REVIEWED BY: 

APPROVED BY: 

OFFICE OF CHEMICAL SAFETY 

AND POLLUTION PREVENTION 

PC Code: 129093 

DP Barcode: 420682 

June 12, 2014 

Registration Review: Preliminary Ecological Risk Assessment and 

Endangered Species Effects Determination for Chlorfenapyr 

Margaret Hathaway, Chemical Review Manager 

Tom Myers, Team Leader 

Risk Management and Implementation Branch II 

Pesticide Re-evaluation Division (7508P) t/l~f(" 

Stephen 

Environmental 

P. Wente, 

Risk 

Ph.D.

Branch 

, Biologist 

I 

~~ 

Environmental Fate and Effects Division (7507P) 

Meghan Radtke, Ph.D., Acting RAPL ~ ~ i.J /I)..//'( 

Environmental Risk Branch I 

Environmental Fate and Effects Division (7507P) t ~, 

<" )\ex. v... -......- I::_ G r r ;.:l-\ I J 

Sujatha Sankula, Ph.D., Branch Chief ( F--_ \.\.:- ;:::::;::::= 

Environmental Risk Branch I 

Environmental Fate and Effects Division (7507P) 

Chlorfenapyr is an insecticide mit~cide with currently registered uses confined to greenhouses, 

where it is applied to indoor food and non-food crops, and structural uses, where it is used as a 

termiticide and crack and crevice treatment. 

In the Preliminary Work Plan (PWP; USEPA 2010a) for chlorfenapyr (CAS No. 122453-73-0; 

PC Code 129093) and Chlorfenapyr Problem Formulation (USEPA 2010b; DP 383511), the 

Agency anticipated conducting a comprehensive ecological risk assessment in support of the 

Registration Review of chlorfenapyr, including an endangered species assessment, for all uses of 

chlorfenapyr and its metabolites of concern. However, due to a label amendment explained 

below and re-examination of potential environmental exposure, the Agency has determined that 

there is no environmental exposure, and therefore there is no risk to non-target organisms. Based 

on this, the Agency has come to a No Effect determination regarding chlorfenapyr's impact on 

federally listed threatened and endangered species (hereafter referred to as "listed" species). 

Based on this same logic, no effects are expected for non-listed species as well. The registration 

review docket for chlorfenapyr is EPA-HQ-OPP- 2010-0467. 

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The Agency typically evaluates the likelihood of an adverse effect, i.e., risk, using a quantitative 

approach where conservative exposure estimates are compared to the most sensitive toxicity 

endpoints. However, in the case of chlorfenapyr, there is a lack of a complete exposure pathway 

from the use site to non-target terrestrial and aquatic organisms. 

The first use identified in the PWP as having potential outdoor environmental exposure was 

application to fruiting vegetables grown in a greenhouse. The Agency believed that exposure 

could occur because the label stated to "Compost any discarded plant material that has been 

treated." Following publication of the PWP, the registrant amended the label to prohibit 

com posting of chlorfenapyr-treated material. Therefore, the Agency has determined that this use 

no longer results in outdoor environmental exposure and a comprehensive ecological risk 

assessment for this use is not needed. 

The second use identified in the PWP as having potential outdoor environmental exposure was 

application to soil underlying a concrete slab prior to the slab being poured (during construction). 

The PWP stated that there is a potential for exposure to chlorfenapyr in adjacent areas via runoff 

from the use site if a major rain event occurred after application, but prior to pouring the concrete 

slab. After re-examining this use pattern, the Agency has determined that the potential for 

outdoor environmental exposure is negligible. This is because only a small area would be treated 

before the concrete is applied, and the time between application and pouring of the concrete slab 

would be minimal. Therefore, the Agency concludes that outdoor environmental exposure 

would not occur as a result of this use and would not lead to ecological risk. 

All other chlorfenapyr use sites are indoors and result in no complete environmental exposure 

pathways, or are crack and crevice treatments with little potential for outdoor release. 

Based on incomplete exposure pathways for all chlorfenapyr uses, the Agency makes a No 

Effects (NE) determination for all listed species as well as a No Habitat Modification 

determination for all designated critical habitats for the currently registered uses of chlorfenapyr. 

If, in the future, chlorfenapyr is considered for additional uses that could result in environmental 

releases, further analysis will need to be undertaken to determine potential effects to non-target 

organisms, including listed species and their designated critical habitat. 

REFERENCES 

USEPA. 2010a. Chlorfenapyr Preliminary Work Plan. Office of Pesticide Programs, United 

States Environmental Protection Agency. Washington, D.C. June 17,2010. 

USEPA. 2010b. Registration Review: Problem Formulation Revised Based on Public Comments 

for Ecological Risk, Environmental Fate, and Endangered Species Assessments for 

Chlorfenapyr (PC Code 129093). Office of Pesticide Programs, United States 

Environmental Protection Agency. Washington, D.C. October 28, 2010. (DP Barcode: 

383511) 

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