ASTM is developing a new standard for assessing vapor intrusion. A vapor intrusion condition may exist where the presence of any volatile chemical in an existing or planned structure resulted from the release of that volatile chemical into the soil or groundwater underlying or in close proximity to that structure.

Because property owners may be held strictly liable for releases of hazardous substances at properties that they either currently own/operate or owned/operated at the time of disposal under CERCLA and because it is required by most lenders, environmental due diligence is routinely performed as a defense for both current and future property owners.

As part of all appropriate inquiries, current and prospective landowners typically follow standards, such as ASTM’s Phase I Environmental Site Assessment (ESA) Standard (E 1527), to determine if a release of a hazardous substance has occurred. However, ASTM’s ESA Standard E 1527 does not address vapor intrusion conditions that property owners and their consultants should be aware of.

To address vapor intrusion conditions, ASTM is currently developing ASTM Standard Practice for Assessment of Vapor Intrusion into Structures on Property Involved in Real Estate Transactions to supplement the ASTM Phase I ESA Standard. The "Vapor Intrusion Standard" is expected to be finalized by the end of 2007.