ISO/TC 209 Standards and Drafts - ISO 14644-8
ISO 14644, Cleanrooms and associate controlled environments - Part 8: Classification of airborne molecular contamination
The DIS level is an important stage in the development of an ISO Standard. This part of ISO 14644 covers the classification of molecular contamination in cleanrooms and associated controlled environments in terms of airborne concentrations of the specific compound or chemical and provides a protocol to include test methods, analysis and time weighted factors within the specification for classification.
This part of ISO 14644 considers only concentrations of airborne molecular contamination between 100 and 10-12 g/m3 under normal cleanroom conditions of temperature, relative humidity and pressure. This part of ISO 14644 is not relevant for application in those industries, processes or production, where the presence of airborne molecular species is not considered a risk to the product or process. This part of ISO 14644 cannot be used to characterize the nature of airborne molecular contaminants.
NOTE. Actual concentrations of airborne molecular contaminants are not normally predictable and typically are variable with time.
This standard does not give a classification of surface molecular contamination.