ABSTRACT
An ordinary room in your home has on average 300,000 airborne particles of 0.5 micron or larger for each cubic foot of air. Thus, if it were cleanroom classified, this typical room would be a class 300,000 clean room. A space with air three times cleaner than the normal interior room has only 100,000 (lOOK) airborne particles for each cubic foot of air. This is the dirtiest cleanroom classification, class 100,000. A room with air ten times cleaner than the class 1 OOK cleanroom would be a class 10K clean room. The lower the classification, the cleaner the room air. A class 10 space is extremely clean, inasmuch as there are no more than ten particles of a size of a half of a micron or larger for each cubic foot of air (353 particles at that size per cubic meter). Cleanrooms or clean work surfaces are rated as class 1, 10, 100, lK, lOK, or lOOK. New requirements for air cleanliness are addressed in the Federal Standard 209E, "Airborne Particulate Cleanliness Classes in Cleanrooms and Clean Zones."
