On November 21, 2005, the American Society for Testing and Materials (ASTM) released a newASTM E1527-05 standard entitled "Standard Practice for Environmental Site Assessments: Phase I Environmental Site Assessment Process". The new ASTM standard is consistent with the new AAI standard released by the USEPA in November 2005.

The purpose of this practice is to define good commercial and customary practice in the US for conducting an environmental site assessment of a parcel of commercial real estate with respect to the range of contaminants within the scope of Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) (42 U.S.C. 9601) and petroleum products. As such, this practice is intended to permit a user to satisfy one of the requirements to qualify for the innocent landowner, contiguous property owner, or bona fide prospective purchaser limitations on CERCLA liability.

More information on this standard can be found obtained from ASTM here.