Because of a reduction of industrial hazard when cotton fiber is washed, methods to differettiate objectively between washed and unwashed cotton fiber were developed and compared. The methods used were thermal (differential scanning calorimetry and thermogravimetric analysis), contact angle, a sink-float (density) method, measurement of potassium content, and chemiluminescence. All methods were successful. A higher ionic potassium content in unwashed cotton is indicated. See also AA TA 22-940 for a discussion of the wettability of unwashed and washed fibers. -- AATA