This test method is useful in determining the approximate amount of nonvolatile inorganic material in leather. This may be in the form of salts or oxides of the elements. In a mixed chrome tannage, the approximate percentage of other elements in the leather may be determined by subtracting the chromic oxide that may be conveniently determined on the ash. (See Test Method D 2807.)

The temperature of 600°C specified is high enough to produce a reproducible result but it does not completely dehydrate such oxides as aluminum oxide, (Al₂O₃) and chromic oxide (Cr₂O₃). Likewise, such salts as sulfates and phosphates may be incompletely dehydrated, and if alkalies and chromium are present simultaneously, oxidation to chromate may occur. Therefore, caution is advised in drawing conclusions based on quantitative relations of the elements.

1.1 This test method covers the determination of total ash in leather.

1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.