ISO 12500-2:2007 specifies the test layout and test procedures required for testing hydrocarbon vapour adsorbent filters used in compressed air systems to determine their effectiveness in removing hydrocarbon vapours. The performance characteristics to be identified are the adsorptive capacity and the pressure drop. ISO 12500-2:2007 defines one method of presenting filter performance as hydrocarbon-vapour capacity, expressed in milligrams, from results obtained under test conditions.