Note: The Vapor Intrusion Toolkit (VIT-1, 2026) published in January 2026 updates the information in this original guidance document. This document has not been amended since publication. Some content may be out of date and may no longer apply. For the most recent information, please visit the Vapor Intrusion Toolkit at https://itrcweb.org/vapor-intrusion-toolkit/.
Vapor intrusion occurs when chemical vapors from contaminated soil or groundwater move upward into buildings and affect indoor air. Exposure to these vapors can potentially impact the health of people who live or work in affected buildings. Vapor intrusion can involve many types of volatile organic compounds, including chlorinated compounds and petroleum hydrocarbons, but petroleum vapor intrusion (PVI) behaves differently because petroleum vapors can naturally break down as they move through soil.
The document Petroleum Vapor Intrusion: Fundamentals of Screening, Investigation, and Management (PVI-1, 2014) provides guidance on how to assess and manage petroleum vapor intrusion at sites contaminated with petroleum hydrocarbons. The document presents an eight-step process that uses screening tools, evaluation strategies, and the principle of vertical separation distance to help determine when further investigation is needed. Two checklists are included to use with the eight-step process to organize and document decisions, one for managing a single site and one for evaluating multiple sites.
Topic(s): Air Quality, Indoor Air, Petroleum Hydrocarbons, Vapor Intrusion
