ISO 14644-8:2006 covers the classification of airborne molecular contamination (AMC) in cleanrooms and associated controlled environments in terms of airborne concentrations of specific chemical substances (individual, group or category) and provides a protocol to include test methods, analysis and time weighted factors within the specification for classification.ISO 14644-8:2006 currently considers only concentrations of AMC between 100 and 10?12 g/m3 under cleanroom operational conditions.ISO 14644-8:2006 is not relevant for application in those industries, processes or production, where the presence of airborne molecular substances is not considered a risk to the product or process.It is not the intention of ISO 14644-8:2006 to describe the nature of airborne molecular contaminants.ISO 14644-8:2006 does not give a classification of surface molecular contamination.