UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON, D.C. 20460 

OFFICE OF CHEMICAL SAFETY 

AND POLLUTION PREVENTION 

MEMORANDUM 

Date: 

SUBJECT: 

FROM: 

THRU: 

TO: 

January 4, 2013 

De Minimis Subgroup Opinion on Polybutene Resins 

Science Policy Panel/Risk Management Forum De Minzmis ubgrou~~ fJ/1 ~r Joel Wolf, Chemical Review Manager rl . Risk Management and Implementation Branch 2 

Pesticide Re-evaluation Division (7508P) 

Office of Pesticide Programs 

Richard Keigwin, Jr. Division Director, PRD 

Donald Brady, Division Director, EFED 

Jack Housenger, Division Director, HED 

Susan Lewis, Acting Division Director, BEAD 

The Science Policy Panel and Risk Management Forum's De Minimis Subgroup (DMS) 

considered the registration review case Polybutene Resins during our December 12, 2012 

meeting. Dana Spatz ofEFED presented EFED's preliminary "no effect" determination for the 

registered uses of poly butene resins. The no effect determination was based on the conclusion 

that effects to federally listed threatened or endangered species are not reasonably expected to 

occur. 

The conclusion of no reasonable expectation of effects to federally listed threatened or 

endangered aquatic species is based on the use pattern and the extremely low water solubility of 

poly butene, whereby aquatic exposure from use of poly butene is expected to be negligible. 

Effects to listed plants are not reasonably expected to occur because exposure to plants is 

anticipated to be limited to the immediate treatment site, and the chance of occurrence of listed 

plants at the immediate treatment site is extremely small. Furthermore, exposure of plants to a 

small amount of synthetic polymer is not expected to result in any adverse effect. 

For terrestrial animals, exposure from dermal absorption or inadvertent ingestion of the product 

by listed species is unlikely, and considering the low toxicity ofpolybutene, it would not be 

expected to approach leveis that would cause toxicity should exposure occur. Concerning 

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physical entanglement with the product, numerous factors make this very unlikely to occur to 

threatened or endangered animal species. These factors include the following lines of evidence: 

• There is a complete exposure pathway, but the quantity used or amount applied is trivial 

• This bird repellent works by a non-toxic mode .of action (sticky surface repels target 

organisms) 

• Treated areas are very small relative to the range of species 

• Geographic location(s) of applications are generally remote from listed species locations. 

• There is a history of exposure to humans and/or environment with minimal toxicity. 

Because ofthese factors, EFED also concludes that use ofpolybutene resins will not result in 

unreasonable adverse effects to non-listed species. 

Members of the DMS questioned whether peregrine falcons, which might perch on ledges to 

which polybutene resins have been applied, might be at risk from contact with the product. One 

member noted that Florida scrub jays could be near use areas as development encroaches on their 

habitat. There have been two reported incidents involving songbird mortalities since polybutene 

resins were registered as a bird repellent in 1963. However, because of the reasons cited above, 

the fact that peregrine falcons are larger and more powerful than the songbirds reported in the 

two incidents, and the small number of incidents over nearly 50 years, the DMS concurs that 

there is no reasonable expectation of effects to federally listed threatened or endangered 

species from use of registered polybutene resins products. The public comment period for 

the polybutene resins case will provide an opportunity to receive additional incident reports, if 

they exist. 

Therefore, the DMS recoinmends that EFED prepare a qualitative endangered species risk 

assessment as they indicated they would in the Polybutene Resins Final Work Plan. This should 

be published with the qualitative human health risk assessment completed on June 13, 2012, 

which found no hiunan health risks of concern. 

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