This SAE Recommended Practice applies to various insulation materials used in vehicles for control of heat and noise and other applications. The purpose of this test is to provide a means to evaluate and compare the corrosiveness of insulation materials. Three panelists compare a sample insulation material to a standard (inert fibrous material). The rationale for the test is that the corrosion of steel should not be greater for the insulation material than for an inert fibrous material.