SERA TR-052-29-03a Imazapyr Human Health and Ecological Risk Assessment FINAL REPORT Submitted to: Paul Mistretta, COR USDA/Forest Service, Southern Region 1720 Peachtree RD, NW Atlanta, Georgia 30309 USDA Forest Service Contract: AG-3187-C-06-0010 USDA Forest Order Number: AG-43ZP-D-11-0012 SERA Internal Task No. 52-29 Submitted by: Patrick R. Durkin Syracuse Environmental Research Associates, Inc. 8125 Solomon Seal Manlius, New York 13104 E-Mail: [email protected] Home Page: www.sera-inc.com December 16, 2011 Table of Contents LIST OF FIGURES ...................................................................................................................... vii LIST OF TABLES ........................................................................................................................ vii LIST OF APPENDICES ............................................................................................................... vii ACRONYMS, ABBREVIATIONS, AND SYMBOLS .............................................................. viii COMMON UNIT CONVERSIONS AND ABBREVIATIONS .................................................... x CONVERSION OF SCIENTIFIC NOTATION ........................................................................... xi EXECUTIVE SUMMARY .......................................................................................................... xii 1. INTRODUCTION ...................................................................................................................... 1 1.1. Chemical Specific Information ............................................................................................ 1 1.2. General Information ............................................................................................................. 3 2. PROGRAMS DESCRIPTION ................................................................................................... 5 2.1. Overview .............................................................................................................................. 5 2.2. Chemical Description and Commercial Formulations ......................................................... 5 2.3. Application Methods ............................................................................................................ 7 2.3.1. Terrestrial Applications ................................................................................................ 7 2.3.2. Aquatic Applications .................................................................................................... 8 2.4. Mixing and Application Rates ............................................................................................. 9 2.4.1. Terrestrial Broadcast Applications ............................................................................... 9 2.4.2. Spot (Foliar) Treatments ............................................................................................. 10 2.4.3. Cut Surface and Basal Bark Treatments ..................................................................... 10 2.4.4. Aquatic Applications .................................................................................................. 10 2.5. Use Statistics ...................................................................................................................... 11 3. HUMAN HEALTH .................................................................................................................. 13 3.1. HAZARD IDENTIFICATION ........................................................................................ 13 3.1.1. Overview ..................................................................................................................... 13 3.1.2. Mechanism of Action .................................................................................................. 13 3.1.3. Pharmacokinetics and Metabolism ............................................................................. 14 3.1.3.1. General Considerations ........................................................................................ 14 3.1.3.2. Absorption............................................................................................................ 15 3.1.3.3. Excretion .............................................................................................................. 16 3.1.4. Acute Oral Toxicity .................................................................................................... 18 3.1.4.1. Experimental Mammals ....................................................................................... 18 3.1.4.2. Case Reports (Human Poisoning) ........................................................................ 19 3.1.5. Subchronic or Chronic Systemic Toxic Effects .......................................................... 20 3.1.6. Effects on Nervous System ......................................................................................... 21 3.1.7. Effects on Immune System ......................................................................................... 23 3.1.8. Effects on Endocrine System ...................................................................................... 23 3.1.9. Reproductive and Developmental Effects .................................................................. 24 ii 3.1.9.1. Developmental Studies ........................................................................................ 24 3.1.9.2. Reproduction Studies ........................................................................................... 25 3.1.10. Carcinogenicity and Mutagenicity ............................................................................ 25 3.1.11.1. Mutagenicity ..................................................................................................... 25 3.1.11.2. Carcinogenicity .................................................................................................. 26 3.1.11. Irritation and Sensitization (Effects on the Skin and Eyes) ...................................... 26 3.1.11.1. Skin Irritation ..................................................................................................... 26 3.1.11.2. Skin Sensitization............................................................................................... 27 3.1.11.3. Ocular Effects .................................................................................................... 27 3.1.12. Systemic Toxic Effects from Dermal Exposure ....................................................... 28 3.1.13. Inhalation Exposure .................................................................................................. 28 3.1.14. Adjuvants and Other Ingredients .............................................................................. 29 3.1.14.1. Other Ingredients ........................................................................................... 29 3.1.14.2. Adjuvants ....................................................................................................... 30 3.1.15. Impurities and Metabolites ....................................................................................... 30 3.1.15.1. Metabolites ......................................................................................................... 30 3.1.15.2. Impurities ........................................................................................................... 31 3.1.16. Toxicological Interactions ........................................................................................ 31 3.2. EXPOSURE ASSESSMENT .......................................................................................... 32 3.2.1. Overview ..................................................................................................................... 32 3.2.2. Workers ....................................................................................................................... 33 3.2.2.1. General Exposures ............................................................................................... 33 3.2.2.1.1. Terrestrial Applications ................................................................................ 33 3.2.2.1.2. Aquatic Applications .................................................................................... 34 3.2.2.2. Accidental Exposures........................................................................................... 35 3.2.3. General Public ........................................................................................................... 36 3.2.3.1. General Considerations ........................................................................................ 36 3.2.3.1.1. Likelihood and Magnitude of Exposure ....................................................... 36 3.2.3.1.2. Summary of Assessments ............................................................................. 37 3.2.3.2. Direct Spray ......................................................................................................... 37 3.2.3.3. Dermal Contact with Contaminated Vegetation .................................................. 38 3.2.3.4. Contaminated Water ............................................................................................ 38 3.2.3.4.1. Accidental Spill ............................................................................................. 38 3.2.3.4.2. Accidental Direct Spray/drift for a Pond or Stream ...................................... 39 3.2.3.4.3. GLEAMS Modeling.....................................................................................