This memorandum, the accompanying human health risk assessment and attachments serve as the HED Revised Preliminary Human Health Risk Assessment for the RED for atrazine. The attachments include: (1) HED Toxicology Chapter dated 01/18/01, L Taylor & R. Hawks (Attachment I), (2) Report of the Hazard Identification Assessment Review Committee (HIARC) memoranda dated 12/21/00, V. Dellarco and K. Baetcke (Attachment II), (3) FQPA Safety Factor Recommendations (11/14/00), B. Tarplee (Attachment III), (4) HED Product and Residue Chemistry Chapter dated 01/18/01, C. Eiden and D. Soderberg (Attachment IV), (5) Anticipated Residues and Acute and Chronic Dietary Exposure Assessments for Atrazine dated 01/18/01, C. Eiden and D. Soderberg (Attachment V), (6) HED Occupational and Residential Exposure Assessment and Recommendations for the Reregistration Eligibility Decision Document for Atrazine dated 01/18/01, G. Bangs (Attachment VI), (7) EFED Drinking Water Exposure Assessment, J. Lin, H. Nelson, and M. Frankenberry (Attachment VII), and (8) Review of Atrazine Incident Reports, J. Blondell (Attachment VIII). These attachments contain the basic information used here to describe the overall exposure and risk estimates associated with the use of atrazine. Cumulative risk assessment, which considers risks from other pesticides which have a common mechanism of toxicity is not addressed in this document. This document contains revisions to the preliminary human health risk assessment dated November 30, 2000 made in response to the Phase I Review 30-day registrant error correction.