SERA TR-056-01-03a Aminocyclopyrachlor Human Health and Ecological Risk Assessment FINAL REPORT Submitted to: Dr. Harold Thistle USDA Forest Service Forest Health Technology Enterprise Team 180 Canfield St. Morgantown, WV 26505 Email: [email protected] USDA Forest Service Contract: AG-3187-C-12-0009 USDA Forest Order Number: AG-3187-D-12-0081 SERA Internal Task No.: 56-001 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 September 27, 2012 Table of Contents LIST OF TABLES ....................................................................................................................... viii LIST OF FIGURES ..................................................................................................................... viii LIST OF APPENDICES ................................................................................................................ ix LIST OF ATTACHMENTS .......................................................................................................... ix ACRONYMS, ABBREVIATIONS, AND SYMBOLS ................................................................. x COMMON UNIT CONVERSIONS AND ABBREVIATIONS .................................................. xii CONVERSION OF SCIENTIFIC NOTATION ......................................................................... xiii EXECUTIVE SUMMARY ......................................................................................................... xiv 1. INTRODUCTION ...................................................................................................................... 1 1.1. Chemical Specific Information ............................................................................................ 1 1.2. Workbooks and Other Attachments ..................................................................................... 2 1.3. General Information ............................................................................................................. 3 2. PROGRAM DESCRIPTION ...................................................................................................... 4 2.1. Overview .............................................................................................................................. 4 2.2. Chemical Description and Commercial Formulations ......................................................... 5 2.2.1. Aminocyclopyrachlor and Related Compounds ........................................................... 5 2.2.2. Formulations ................................................................................................................. 7 2.2.2.1. Aminocyclopyrachlor as Sole Active Ingredient ................................................... 7 2.2.2.2. Aminocyclopyrachlor with Other Herbicides ........................................................ 9 2.3. Application Methods ............................................................................................................ 9 2.4. Mixing and Application Rates ........................................................................................... 10 2.5. Use Statistics ...................................................................................................................... 11 3. HUMAN HEALTH .................................................................................................................. 12 3.1. HAZARD IDENTIFICATION ........................................................................................ 12 3.1.1. Overview ..................................................................................................................... 12 3.1.2. Mechanism of Action .................................................................................................. 13 3.1.3. Pharmacokinetics and Metabolism ............................................................................. 13 3.1.3.1. General Considerations ........................................................................................ 14 3.1.3.2. Dermal Absorption............................................................................................... 15 3.1.3.3. Excretion .............................................................................................................. 16 3.1.4. Acute Oral Toxicity .................................................................................................... 17 3.1.5. Subchronic or Chronic Systemic Toxic Effects .......................................................... 17 3.1.6. Effects on Nervous System ......................................................................................... 18 3.1.7. Effects on Immune System ......................................................................................... 19 3.1.8. Effects on Endocrine System ...................................................................................... 20 3.1.9. Reproductive and Developmental Effects .................................................................. 20 3.1.9.1. Developmental Studies ........................................................................................ 20 3.1.9.2. Reproduction Studies ........................................................................................... 21 ii 3.1.10. Carcinogenicity and Mutagenicity ............................................................................ 22 3.1.11. Irritation and Sensitization (Effects on the Skin and Eyes) ...................................... 22 3.1.11.1. Skin Irritation ..................................................................................................... 22 3.1.11.2. Skin Sensitization............................................................................................... 23 3.1.11.3. Ocular Effects .................................................................................................... 23 3.1.12. Systemic Toxic Effects from Dermal Exposure ....................................................... 23 3.1.12.1. Acute Dermal Toxicity ...................................................................................... 23 3.1.12.2. Subchronic Dermal Toxicity .............................................................................. 24 3.1.13. Inhalation Exposure .................................................................................................. 24 3.1.14. Adjuvants and Other Ingredients .............................................................................. 25 3.1.14.1. Other Ingredients (Inerts) ................................................................................... 25 3.1.14.2. Adjuvants ........................................................................................................... 25 3.1.15. Impurities and Metabolites ....................................................................................... 26 3.1.15.1. Metabolites ......................................................................................................... 26 3.1.15.2. Impurities ........................................................................................................... 27 3.1.16. Toxicological Interactions ........................................................................................ 28 3.2. EXPOSURE ASSESSMENT .......................................................................................... 29 3.2.1. Overview ..................................................................................................................... 29 3.2.2. Workers ....................................................................................................................... 30 3.2.2.1. General Exposures ............................................................................................... 30 3.2.2.2. Accidental Exposures........................................................................................... 31 3.2.3. General Public ........................................................................................................... 33 3.2.3.1. General Considerations ........................................................................................ 33 3.2.3.1.1. Likelihood and Magnitude of Exposure ....................................................... 33 3.2.3.1.2. Summary of Assessments ............................................................................. 33 3.2.3.2. Direct Spray ......................................................................................................... 34 3.2.3.3. Dermal Exposure from Contaminated Vegetation ............................................... 35 3.2.3.4. Contaminated Water ............................................................................................ 35 3.2.3.4.1. Accidental Spill ............................................................................................. 35 3.2.3.4.1.1. Aminocyclopyrachlor ............................................................................ 35 3.2.3.4.1.2. Cyclopropanecarboxylic acid................................................................. 36 3.2.3.4.2. Accidental Direct Spray/drift for a Pond or Stream ...................................... 38 3.2.3.4.2.1. Aminocyclopyrachlor ............................................................................ 38 3.2.3.4.2.2. Cyclopropanecarboxylic acid................................................................. 39 3.2.3.4.3. GLEAMS Modeling.....................................................................................