This standard specifies a method for the determination of sulfur content in cellulosic materials by X-Rays fluorescence. Sulfur may be present in the form of sulfate esters, affecting the thermal stability of the material, or in the form of salts, resulting in solution haze. This method is suitable for the range of sulfur content from about 10 ppm to 20% and can be used as an alternative to test method D871. Samples are subject to treatment to remove unbound sulfur compounds. The standard does not cover all safety issues. Users need to evaluate and implement necessary safety measures on their own.