Describes an atomic absorption spectrometric method for determining copper content of rubbers. Applicable to raw rubber and rubber products having copper contents above 1 ppm. Copper contents below this limit may be determined, provided that suitable adjustments are made to the mass of the test portion and/or to the concentrations of the solutions used. Covers normative references, principle, reagents, apparatus, sampling, procedure, expression of results, test report and method of standard additions. A table gives standard calibration solutions.