ISO Publishes New Cleanrooms Contamination Standard

Geneva, Switzerland (Aug. 10)-The International Organization for Standardization (ISO,  www.iso.org) has formally issued and published standard ISO 4644-8:2006, Cleanrooms and associated controlled environments-Part 8: Classification of airborne molecular contamination. The document 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. The standard currently considers concentrations of AMC between 1 and 10–12 g/m³ under cleanroom operational conditions.

The formalization and publication of the new ISO standard follows the typical voting and comment period by ISO member nations on the ISO/Final Draft International Standard (FDIS) released by The Institute of Environmental Sciences and Technology (IEST, Rolling Meadows, IL, www.iest.org) in February 2006. The ISO/FDIS draft provided informative annexes on related contamination control topics, including parameters for consideration, typical contaminating chemicals and substances, typical methods of measurement and analysis, and considerations of specific requirements for separative enclosures.