This guidance is the sixth annex of the Risk Assessment Guidance for Superfund (RAGS), Volume I, which address human health risk at Superfund sites. Parts A, B, C, 0 and E of Volume I addressed other aspects of hurnan health risk. RAGS Part F was developed by a workgroup composed of toxicologists and risk assessors in the EPA Superfund Program and other hazardous waste programs in EPA regional offices, with significant involvement from the Office of Research and Development (ORD), the Office of Air Quality Planning and Standards (OAQPS), the Office of Children's Health Protection and Environmental Education (OCHPEE), and the Office of Solid Waste and Emergency Response (OSWER), This guidance received internal EPA review in July 2007 and external peer review and state risk assessor review in April-May 2008.