ISO 8573-1:2010 specifies purity classes of compressed air with respect to particles, water and oil independent of the location in the compressed air system at which the air is specified or measured. ISO 8573-1:2010 provides general information about contaminants in compressed-air systems as well as links to the other parts of ISO 8573, either for the measurement of compressed air purity or the specification of compressed-air purity requirements. In addition to the above-mentioned contaminants of particles, water and oil, ISO 8573-1:2010 also identifies gaseous and microbiological contaminants. Guidance is given in Annex A on the application of ISO 8573-1:2010.