SERA TR-052-22-03b Glyphosate 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-09-0031 SERA Internal Task No. 52-22 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 March 25, 2011 Table of Contents LIST OF TABLES ......................................................................................................................... xi LIST OF FIGURES ...................................................................................................................... xii LIST OF APPENDICES ............................................................................................................... xii LIST OF ATTACHMENTS ......................................................................................................... xii ACRONYMS, ABBREVIATIONS, AND SYMBOLS .............................................................. xiii COMMON UNIT CONVERSIONS AND ABBREVIATIONS ................................................. xvi CONVERSION OF SCIENTIFIC NOTATION ........................................................................ xvii EXECUTIVE SUMMARY ....................................................................................................... xviii 1. INTRODUCTION ...................................................................................................................... 1 1.1. Chemical Specific Considerations ....................................................................................... 1 1.2. General Considerations ........................................................................................................ 3 2. PROGRAMS DESCRIPTION.................................................................................................... 5 2.1. Overview .............................................................................................................................. 5 2.2. Chemical Description and Commercial Formulations ......................................................... 5 2.2.1. Chemical Description.................................................................................................... 5 2.2.2. Commercial Formulations ............................................................................................ 6 2.2.3. Classification of Formulations ...................................................................................... 9 2.2.3.1. Low Toxicity/High Confidence ........................................................................... 11 2.2.3.2. Low Toxicity/Medium Confidence ...................................................................... 11 2.2.3.3. Low Toxicity/Low Confidence ............................................................................ 11 2.2.3.4. Medium Toxicity/Medium Confidence ............................................................... 12 2.2.3.5. Medium Toxicity/Low Confidence...................................................................... 12 2.2.3.6. High Toxicity/High Confidence .......................................................................... 12 2.2.3.7. High Toxicity/Medium Confidence ..................................................................... 13 2.2.3.8. High Toxicity/Low Confidence ........................................................................... 13 2.2.3.9. Formulations Not Classified ................................................................................ 14 2.3. Application Methods ......................................................................................................... 15 2.3.1. Foliar Applications..................................................................................................... 15 2.3.2. Other Ground Applications ........................................................................................ 15 2.3.3. Aquatic Applications ................................................................................................. 16 2.4. Mixing and Application Rates .......................................................................................... 16 2.4.1. Foliar Applications..................................................................................................... 16 ii 2.4.2. Aquatic Applications ................................................................................................. 17 2.5. Use Statistics ..................................................................................................................... 17 3. HUMAN HEALTH .................................................................................................................. 19 3.1. HAZARD IDENTIFICATION ........................................................................................ 19 3.1.1. Overview ..................................................................................................................... 19 3.1.2. Mechanism of Action .................................................................................................. 20 3.1.3. Pharmacokinetics and Metabolism ............................................................................. 21 3.1.3.1. General Considerations ........................................................................................ 21 3.1.3.2. Dermal Absorption............................................................................................... 25 3.1.3.2.1. First-Order Dermal Absorption ..................................................................... 25 3.1.3.2.2. Zero-Order Dermal Absorption .................................................................... 26 3.1.3.3. Excretion .............................................................................................................. 27 3.1.4. Acute Oral Toxicity .................................................................................................... 27 3.1.4.1. Technical Grade Glyphosate ................................................................................ 27 3.1.4.2. Glyphosate Formulations ..................................................................................... 29 3.1.4.3. Surfactants ............................................................................................................ 32 3.1.4.3.1. Acute Oral Toxicity ...................................................................................... 32 3.1.4.3.2. Joint Action of Glyphosate and Surfactant ................................................... 32 3.1.4.4. Suicides and Suicide Attempts Involving Glyphosate Formulations .................. 36 3.1.5. Subchronic or Chronic Systemic Toxic Effects .......................................................... 38 3.1.5.1. Technical Grade Glyphosate ................................................................................ 38 3.1.5.2. Glyphosate Formulations ..................................................................................... 39 3.1.5.3. POEA Surfactant .................................................................................................. 39 3.1.6. Effects on Nervous System ......................................................................................... 40 3.1.6.1. Technical Grade Glyphosate ................................................................................ 41 3.1.6.2. Glyphosate Formulations ..................................................................................... 43 3.1.7. Effects on Immune System ......................................................................................... 45 3.1.7.1. Technical Grade Glyphosate ................................................................................ 45 3.1.7.2. Glyphosate Formulations ..................................................................................... 46 3.1.8. Endocrine Effects ........................................................................................................ 47 3.1.9. Reproductive and Developmental Effects .................................................................. 51 3.1.9.1. Developmental Studies ........................................................................................ 51 3.1.9.1.1. Glyphosate .................................................................................................... 51 3.1.9.1.2. Glyphosate Formulations .............................................................................. 52 iii 3.1.9.1.3. Surfactants ..................................................................................................... 54 3.1.9.2. Reproduction Studies ........................................................................................... 55 3.1.9.2.1. Laboratory Studies on Glyphosate ................................................................ 55 3.1.9.2.2. MON 0818 Surfactant ................................................................................... 56 3.1.9.2.3. Human Experience with Formulations ......................................................... 57 3.1.9.2.4. Field Studies in Mammals ............................................................................ 58 3.1.9.3. Effects on Testes and Testosterone ...................................................................... 59 3.1.10. Carcinogenicity and Mutagenicity ...........................................................................