The purpose of this standard is to describe a procedure for determining the amount of acetone-soluble matter in molded or laminated phenolic products. In molded phenolic products, acetone extraction should be considered only as a quantitative expression of a property that is normally associated with the degree of curing, but there is no rigorous relationship between the optimal mechanical and electrical properties of a well-cured part and the value Numerical acetone extraction test. The amount of substance soluble in acetone is affected by: a) Nature of the resin and charge. b) Lubricant. c) Molding temperature. d) Curing time. e) Thickness of the section from which the sample is taken. f) Nature of the molded piece. g) Molding technique. h) Sample grinding method, etc. For laminated phenolic products, ketone extraction indicates the variation in the degree of cure, in the content and type of resin used, the presence of plasticizers or other acetone-extractable addition products, and, in general, is affected by the same factors as in the case of phenolic moldings. The variations produced by such causes can be 3 to 4% in the amount of soluble substance. For this reason, the method can only be used as a comparative test to measure lack of cure.