WASHINGTON, D.C. 20460
                                      JAN 10 200!
 MEMORANDUM                                                           OFRCEOF
                                                                          THE ADMINISTRATOR
 SUBJECT:   Risk Characterization Handbook

 TO:          Assistant Administrators
              Regional Administrators
              General Counsel
              Chief Financial Officer
              Inspector General
              Associate Administrators

       I am very pleased to present the new Science Policy Council Risk Characterization
 Handbook prepared for EPA staff and managers as a guide to risk characterization. This
 Handbook is the product of efforts by hundreds of EPA employees who contributed their time
 over the past five years to implement the Administrator's 1995 Risk Characterization Policy.
 The Handbook addresses the many recommendations and comments received during its
 development.  The Administrator and I believe that the Risk Characterization Handbook will
 contribute greatly to the Agency's goal of Sound Science and enhance the quality and credibility
 of Agency decisions. We encourage Agency personnel to follow its guidance when developing
 risk characterizations for risk assessments.

       The Risk Characterization Handbook includes guidance in the form of critical elements
 to be found in a risk characterization.  It also provides case studies, which will be updated to
 reflect new developments in Agency policy over time, as examples to model your risk
 characterizations. Furthermore, EPA risk assessments to inform decision-making cannot be
 sound and credible without your support to ensure that the risk assessment process is transparent
 and that the risk assessment products are consistent, clear and reasonable.  These principles
 should guide each risk characterization.

      Following the style of the Peer Review Handbook, the Risk Characterization Handbook
 is written in a plain English, question-and-answer format that provides easy, user-friendly
 guidance for generating useful risk characterizations. I believe it will be an excellent reference
 and will enhance and reinforce the high standard of risk assessment practiced in all our programs
 and regions.
                                 W. Michael McCabe
                                 Deputy Administrator
                                                                        Printed with Soy/Canola Ink on paper that
                                                                        contains at least 50% recycled fiber