This International Standard specifies a method for the determination of the amount of water-extractable protein in natural rubber (NR) gloves for medical use. The method is potentially suitable for the determination of extractable protein in other articles made from NR latex; however the extraction procedures and times have not been validated and will vary with the type of article to be tested. Other methods for the determination of specific proteins in medical gloves exist (see Annex C) but they are not of general applicability. This International Standard is concerned solely with the method of assay. It is not concerned with sampling nor does it purport to address the safety implications of the values obtained or requirements for labelling.