Full Description Ethanol is used as a blending agent added to gasoline. Sulfates are indicated in filter plugging deposits and fuel injector deposits. When fuel ethanol is burned, sulfates may contribute to sulfuric acid emissions. Ethanol acceptability for use depends on the sulfate content. Sulfate content, as measured by this test method, can be used as one measure of determination of the acceptability of ethanol for automotive spark-ignition engine fuel use.