API Publ 4709

The process of calculating human health risk-based screening levels for total petroleum hydrocarbons (TPH) is described in an easy-to-understand question and answer format. (Risk-based screening levels (RBSLs) are chemical-specific concentrations in environmental media that are considered protective of human health). Risk assessment concepts developed by the EPA, and the research groups such as the Petroleum Environmental Research Forum (PERF) and the Total Petroleum Hydrocarbon Criteria Working Group (TPHCWG), are used to calculate RBSLs for TPH in crude oil and condensates obtained from around the world. These methodologies were also applied to polyaromatic hydrocarbons (PAHs), metals, and benzene in TPH. Additional resources contained in this manual include a description of the physical and chemical characteristics of crude oil, condensate, and E&P wastes (contrasted with refined products), a summary of the federal regulatory status of E & P wastes, and a listing of key equations used for calculating RBSLs.