United States Office of Science Policy EPA 100-B-00-002 Environmental Protection Office of Research and Development December 2000 Agency Washington, DC 20460 www.epa.gov Science Policy Council HANDBOOK EPA 100-B-00-002 December 2000 U.S. Environmental Protection Agency RISK CHARACTERIZATION HANDBOOK Prepared for the U.S. Environmental Protection Agency by members of the Risk Characterization Implementation Core Team, a group of EPA’s Science Policy Council Principal Authors John R. Fowle III, Ph.D. Kerry L. Dearfield, Ph.D. Science Advisory Board Office of Science Policy Office of the Administrator Office of Research and Development Science Policy Council U.S. Environmental Protection Agency Washington, DC 20460 Page ii Risk Characterization Handbook DISCLAIMER This document has been reviewed in accordance with U.S. Environmental Protection Agency policy and approved for publication and distribution. Mention of trade names or commercial products does not constitute endorsement or recommendation for use. Risk Characterization Handbook Page iii TABLE OF CONTENTS FOREWORD ........................................................... Page vii ACKNOWLEDGMENTS .................................................. Page x OVERVIEW OF THIS RISK CHARACTERIZATION HANDBOOK ............... Page 1 Outline of the Basic Structure of the Risk Characterization Guide ............. Page 2 RISK CHARACTERIZATION GUIDE ....................................... Page 3 1. INTRODUCTION TO RISK CHARACTERIZATION ......................... Page 5 1.1 Overview ................................................... Page 5 1.2 Understanding Risk Characterization ............................ Page 10 1.2.1 What is Risk Characterization? ........................... Page 10 1.2.2 Are Risk Characterizations Written As Part of Ecological Risk Assessments Different from Those Written As Part of Human Health Risk Assessments? ............................... Page 11 1.2.3 Are Risk Assessment and Risk Characterization the Same? ..... Page 13 1.2.4 Are Risk Characterization and Risk Communication the Same? . Page 13 1.2.5 What is the Value of Risk Characterization in the Regulation Development Process? .................................. Page 13 1.2.6 What Role does Risk Characterization have in Regulatory Negotiations? ......................................... Page 14 1.2.7 Do Risk Characterizations Need Peer Review? ............... Page 14 1.3 Risk Characterization Principles ................................ Page 14 1.3.1 What are Criteria for Transparency? ....................... Page 15 1.3.2 What are Criteria for Clarity? ............................ Page 16 1.3.3 What are Criteria for Consistency? ........................ Page 17 1.3.4 What are Criteria for Reasonableness? ..................... Page 18 1.4 Overview Presentation of TCCR Principles ....................... Page 19 1.5 The Roles of People and Organizations in Risk Characterization ....... Page 20 1.5.1 Who is Ultimately Accountable for Risk Characterization? ..... Page 20 1.5.2 Who Are the Agency Staff Involved in Risk Characterization? .. Page 20 1.5.3 What Are My Responsibilities as a Risk Assessor? ........... Page 20 1.5.4 What Are My Responsibilities as a Risk Manager? ........... Page 22 1.5.5 What Does the Risk Characterization Policy Tell Risk Assessors? ....................................... Page 24 Page iv Risk Characterization Handbook 1.5.6 How Will Risk Characterization Help the Risk Assessor? ...... Page 24 1.5.7 How Will Risk Characterization Help the Risk Manager? ...... Page 24 1.5.8 Which Office/Region or Other Agency is Responsible for Writing the Risk Characterization? ........................ Page 25 1.5.9 What is the Responsibility of Organizations that Submit Risk Assessments to EPA? .............................. Page 25 1.5.8 What is the Role of the Science Policy Council (SPC)? ........ Page 26 2. PREPARING FOR A RISK ASSESSMENT AND ITS RISK CHARACTERIZATION – PLANNING AND SCOPING ........................................ Page 27 2.1 Overview .................................................. Page 27 2.2 Planning and Scoping ........................................ Page 27 2.2.1 What Should You Discuss During Planning and Scoping? ...... Page 28 2.2.2 Should the Planning and Scoping Discussion Focus on What the Risk Assessment Results Should Be? ................... Page 29 2.2.3 What are Possible Products Emerging from Planning and Scoping? ......................................... Page 29 2.2.4 What Are the Benefits of Planning and Scoping? ............. Page 30 2.2.5 Who Does Planning and Scoping? ......................... Page 31 2.2.6 When Does the Risk Assessor/Risk Manager Dialog End? ...... Page 31 2.3 Typology for Risk Characterization .............................. Page 31 3. ELEMENTS OF A RISK CHARACTERIZATION........................... Page 35 3.1 Overview .................................................. Page 35 3.2 Elements of a Risk Characterization ............................. Page 35 3.2.1 Can a “Bright Line” or Number be the Risk Characterization? ... Page 36 3.2.2 What Key Information Needs to Be Identified During the Risk Assessment Process to Prepare for Risk Characterization? ...... Page 37 3.2.3 How Do I Put the Risks Estimated in this Assessment into a Context with Other Similar Risks? ....................... Page 37 3.2.4 How Do I Address Sensitive Populations, Ecosystems and Species? .......................................... Page 38 3.2.5 What are Scientific Assumptions and How Do I Address Them? .............................................. Page 39 3.2.6 What Are Policy Choices and How Do I Address Them? ...... Page 40 3.2.7 How Do I Address Variability? ........................... Page 40 3.2.8 How Do I Address Uncertainty? .......................... Page 40 3.2.9 How Do I Address Bias and Perspective? ................... Page 41 3.2.10 How do I Address Strengths and Weaknesses? ............... Page 41 Risk Characterization Handbook Page v 3.2.11 What Are the Major Conclusions to Carry Forward? .......... Page 42 3.2.12 How Do I Describe the Alternatives Considered? ............. Page 43 3.2.13 How Do I Address Research Needs? ....................... Page 43 3.3 Should Decisions be Delayed Until Research is Completed? .......... Page 44 4. RISK CHARACTERIZATION-RELATED PRODUCTS ...................... Page 45 4.1 Overview .................................................. Page 45 4.2 Products of Risk Characterization ............................... Page 45 4.2.1 What is the Technical Risk Characterization? ................ Page 46 4.2.2 What are Risk Characterization Products I Can Prepare for Risk Managers? ........................................... Page 46 4.2.3 What are Risk Characterization Products I Can Prepare for Other Audiences, Like the Public? ............................. Page 47 4.3 Audiences for Risk Characterization Products ..................... Page 47 4.3.1 Who Are the Audiences for Risk Characterization Products? .... Page 47 4.3.2 Can I Use a Single Risk Characterization Product for All Audiences? ........................................... Page 48 4.3.3 How Much Technical Detail is Needed for Different Audiences? ........................................... Page 48 4.3.4 How Do I Ensure that the Irreducible Set of Risk Characterization Information is Carried Forward in All Risk Characterization Products? ............................................ Page 49 4.4 Risk Characterization Format and Length ......................... Page 49 4.4.1 Is There a Standard Format for a Risk Characterization? ....... Page 49 4.4.2 What is an Appropriate Length for a Risk Characterization? .... Page 50 5. INFORMING DECISION MAKERS ...................................... Page 51 5.1 Overview .................................................. Page 51 5.2 Science in Decision Making ................................... Page 51 5.2.1 Is the Risk Assessment the Single Driving Force Behind Decision Making? ..................................... Page 51 5.3 Decision-Making Factors ...................................... Page 51 5.3.1 What Are the Major Factors that Affect Decision Making? ..... Page 51 5.4 Characterization of Non-Science Factors ......................... Page 54 5.4.1 Are the Economic and Other Non-Risk Assessments Subject to Characterization? ...................................... Page 54 5.4.2 Can the Principles of TCCR Apply to Characterizations of the Other Factors? ........................................ Page 54 Page vi Risk Characterization Handbook 6. ADMINISTRATIVE ISSUES ........................................... Page 55 6.1 Overview .................................................. Page 55 6.2 Risk Characterization Record .................................. Page 55 6.2.1 What is the Risk Characterization Record? .................. Page 55 6.2.2 How Can the Risk Characterization Record Improve the Risk Characterization Process? ............................... Page 55 6.2.3 Where Should the Risk Characterization Record be Kept and For How Long? ....................................... Page 56 6.3 Budget Planning ............................................. Page 56 6.4 Legal Considerations ......................................... Page 56 6.4.1 Are There Legal Ramifications from the Risk Characterization Policy? .............................................. Page 56 6.4.2 Is Legal Advice Needed? ................................ Page 56 6.5 Peer Review of Risk Characterization Handbook ................... Page 57 SUBJECT INDEX ....................................................... Page 59 COMMONLY USED ACRONYMS ......................................... Page 61 APPENDIX A ......................................................... Page A-1 POLICY FOR RISK CHARACTERIZATION .......................... Page A-1 APPENDIX B ......................................................... Page B-1 WAQUOIT BAY CASE STUDY .................................... Page B-1 APPENDIX C ......................................................... Page C-1 GENERIC KETONE CASE STUDY ................................. Page C-1 APPENDIX D ......................................................... Page D-1 MITEC CASE STUDY ............................................ Page D-1 APPENDIX E ......................................................... Page E-1 MIDLOTHIAN CASE STUDY...................................... Page E-1 APPENDIX F.......................................................... Page F-1 References Concerning Risk Characterization .......................... Page F-1 References of EPA Risk Assessment Guidelines ........................ Page F-2 Risk Characterization Handbook Page vii FOREWORD This Handbook was prepared by the Science Policy Council (SPC) for EPA staff and managers and others as a guide to Risk Characterization. It implements EPA’s March 1995 Risk Characterization Policy which improved on the foundation of the February 1992 Agency-wide policy for risk characterization. Both the 1992 and 1995 documents point out that “... scientific uncertainty is a fact of life (and) ... a balanced discussion of reliable conclusions and related uncertainties enhances, rather than detracts, from the overall credibility of each assessment …”. Both also note that while the role of science to inform but not make decisions is widely recognized in EPA, and in the larger risk assessment and regulatory community, these communities often use the risk assessment number as the stated reason for decisions, not always clearly highlighting the legal, economic, social and other non-scientific issues that also go into the decision. From the start it was recognized that implementation of this policy would require a culture change at EPA and that achieving an Agency-wide culture change would not be effective if imposed from the top down. Thus, every effort was made to engage career EPA employees, including risk assessors, risk managers and senior decision-makers across the Agency to help implement the policy. The effort was monumental, directly involving several hundred Agency employees in all Offices and Regions. A Risk Characterization Implementation Team was established with members from each Region and Program Office, including the Office of General Counsel, to guide and direct the initial efforts to implement the policy. During the dialog that led to the decision to prepare a single guidance document, the SPC heard from the Programs and Regions about the need for tools and case studies to make the guidance understandable and assure consistent implementation. This Handbook provides a single, centralized body of risk "If I send a man to buy a horse for me, I characterization implementation guidance for expect him to tell me that horse's points -- Agency risk assessors and risk managers to not how many hairs he has in his tail." help make the risk characterization process Abraham Lincoln transparent and the risk characterization products clear, consistent and reasonable (TCCR). TCCR became the underlying principle for a good risk characterization. The elements of a risk characterization (among them, for example, key findings, policy choices, uncertainty and variability) describe in a straight-forward fashion the critical points that a good risk characterization should contain to make it valuable in any Agency risk assessment. Page viii Risk Characterization Handbook This Handbook has two parts. The first is the Risk Characterization guidance itself. The second part comprises the Appendices which contain the Risk Characterization Policy, the risk characterization case studies and references. As mentioned earlier, hundreds of people from across the Agency were instrumental in the preparation of this Handbook, guided by the SPC and its Risk Characterization Team. They were essential in bringing this effort to fruition. In addition, I want to give a special acknowledgment to the principal authors, Jack Fowle and Kerry Dearfield -- their hard work and persistence made this Handbook a reality. I also want to recognize the thoughtful and helpful input that the recently retired Executive Director of the Science Policy Council, Dr. Dorothy Patton, provided. The Agency is indebted to her for her guidance, patience and support. It is with great pleasure that I present the Risk Characterization Handbook. Norine E. Noonan, Ph.D. Assistant Administrator Office of Research and Development Risk Characterization Handbook Page ix Science Policy Council W. Michael McCabe, OA, Chair Norine Noonan, ORD, Vice-Chair Donald Barnes, OA Robert Brenner, OAR Tudor Davies, OW Steven Galson, OPPTS Sylvia Lowrance, OECA Albert McGartland, OPEI William Muszynski, Region 2 Michael Ryan, OCFO Michael Shapiro, OSWER Elaine Stanley, OEI Ramona Trovato, OCHP Science Policy Council Steering Committee Donald Barnes, OA Michael Brody, OCFO Reginald Cheatham, OEI Patricia Cirone, Region 10 William Farland, ORD Michael Feldman, OCFO Penelope Fenner-Crisp, OPPTS Michael Firestone, OCHP Jerri-Anne Garl, Region 5 Peter Grevatt, OSWER Roland Hemmett, Region 2 Kate Mahaffey, OPPTS Carl Mazza, OAR James Nelson, OGC Jennifer Orme-Zavaleta, ORD Peter Preuss, ORD Larry Reed, OSWER Joseph Reinert, OPEI Rosemarie Russo, Region 4 Vanessa Vu, ORD Mary Ellen Weber, OPPTS Jeanette Wiltse, OW William Wood, ORD Science Policy Council Staff Edward Bender Kerry Dearfield James Rowe