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

# Minz**mis ubgrou** **~~**

# fJ/1**~r** Joel Wolf, Chemical Review Manager 

# rl
. Risk Management and Implementation Branch 2 Pesticide Re-evaluation Division (7508P) Office ofPesticide 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 ofEFEDpresented EFED'spreliminary "no effect" determination for the registered uses ofpolybutene resins. The no effect determination was based onthe conclusion that effects to federally listed threatened or endangered species are not reasonably expectedto occur. The conclusion ofno reasonable expectation ofeffects to federally listed threatened or endangered aquatic species is based on the use pattern and the extremely lowwater solubility of poly butene, whereby aquatic exposure from use ofpolybutene 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 ofoccurrence oflisted plants at the immediate treatment site is extremely small. Furthermore, exposure ofplants to a small amount ofsynthetic polymer is not expected to result in any adverse effect. Forterrestrial animals, exposure from dermal absorption or inadvertent ingestion ofthe product by listed species is unlikely, and considering the lowtoxicity ofpolybutene, it would not be expected to approach leveis that would cause toxicity should exposure occur. Concerning
Page 1 of2physical entanglement withthe product, numerous factors make this very unlikely to occurto threatened or endangered animal species. These factors include the following lines ofevidence:
• There is a complete exposure pathway, butthe quantity used oramount applied is trivial
• This bird repellent works by a non-toxic mode
.ofaction (sticky surface repels target organisms)
• Treated areas are very small relative to the range ofspecies
• Geographic location(s) ofapplications are generally remote from listed species locations.
• There is a history ofexposure to humans and/or environment with minimal toxicity. Because ofthese factors, EFED also concludes that use ofpolybuteneresins will not result in unreasonable adverse effects to non-listed species. Members ofthe DMS questioned whetherperegrine falcons, whichmight perch on ledges to which polybutene resins have been applied, might be at risk from contactwith the product. One member noted that Florida scrubjays 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 ofthe reasons cited above, the fact thatperegrine falcons are larger and more powerful than the songbirds reported in the two incidents, and the small number ofincidents overnearly 50 years, the DMS concurs that there is no reasonable expectation ofeffects to federally listed threatened orendangered species from use ofregistered polybutene resins products. The public commentperiod for the polybutene resins case will provide an opportunityto 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 withthe qualitative human health risk assessment completed onJune 13, 2012, which found no hiunan health risks ofconcern.

Page 2 of2