This document specifies two methods for the determination of ash from raw rubbers, compounded rubbers and vulcanizates using a thermogravimetric analyser (TGA). The methods are applicable to raw, compounded or vulcanized rubbers of the M, O, R and U families described in ISO 1629: Method A is applicable for the determination of the ash from raw rubbers. Method B is applicable for the determination of the ash from compounded or vulcanized rubbers. The methods are not applicable for the determination of the ash from raw rubbers, compounded or vulcanized rubbers containing chlorine, bromine or iodine. This document does not cover the interpretation of the ash results from the inorganic chemical contents of compounded or vulcanized rubbers.