5.1 The sulfated ash may be used to indicate the level of known metal-containing additives or impurities in an organic material. When phosphorus is absent, barium, calcium, magnesium, sodium and potassium are converted to their sulfates. Tin and zinc are converted to their oxides.

5.2 This standard may be used for research and development, specification acceptance and quality assurance purposes.

1.1 This standard describes the determination of sulfated ash content (sometimes called residue-on-ignition) of organic materials by thermogravimetry. The method converts common metals found in organic materials (such as sodium, potassium, lithium, calcium, magnesium, zinc, and tin) into their sulfate salts permitting estimation of their total content as sulfates or oxides. The range of the test method is from 0.1 to 100  % metal content.

1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.3 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 to determine the applicability of regulatory limitations prior to use.