Corrosion control documents are essential inputs into effective mechanical integrity programs and risk-based inspection programs. They have been referred to by different acronyms, including Material Operating Envelopes (MOEs); Critical Process Variables (CPVs); Corrosion Manuals; Corrosion Control Documents (CCDs) and others. They can be combined in a risk-based inspection program implementation or can be standalone documents. They are particularly useful for capturing in one document the essential elements of a chemical or refining process that influence corrosion, i.e. materials of construction, process stream chemistry, operating conditions and damage mechanisms.