A cleanroom is a room in which the concentration of airborne particles is controlled to specific limits. They are classified by the numbers of particles per cubic meter per minute. Sizes of particles which are controlled usually range from 0.1 to 10 micrometers. Room classifications are described in ISO-14644-1; "Cleanrooms and associated controlled environments-Part I-Classification of air cleanliness" They range from ISO Class I through 9.
SAFETY, AND SANITATION.
Cleanrooms may be unidirectional (laminar), non-unidirectional (turbulent), or mixed airflow. Clients may choose from a variety of tests, depending upon their needs. A partial list from the ISO Standards 14644-1, 14644-2 and 14644-3-Test Methods, or Institute of Environmental Sciences and Technology document