Phase Is are conducted per ASTM E 1527-13 and include several major components: a site reconnaissance, completion of a User Questionnaire, a regulatory database search, interviews with persons knowledgeable of the property, and a review of reasonably ascertainable and readily available historical sources to identify the use of the property back to 1940 or its first developed use, whichever is earlier.  As such, the ASTM E 1527-13 Standard Practice provides specific guidance as to what must be addressed.  However, there is no ASTM standard for Desktop Reviews (more commonly called Risk Search with Risk Assessments-RSRAs).  Therefore, RSRAs differ from consultant to consultant and also do not provide protection on CERCLA.