What is a cleanroom? A cleanroom is a special type of room where the level of airborne particles is carefully controlled. Cleanrooms are classified on an ISO scale. (There are also some alternative classification systems in use in the United States.) The ISO 14644-1:2015 standard runs from one to nine and dictates the level of particles that are permitted. ISO 1 represents the highest standard.
A sample from an ISO 1 cleanroom should contain 10 or fewer particles measuring 0.1 microns (micrometres, µm) and two or fewer particles at 0.2 microns per cubic metre of air. Contrast that with ISO 9 (regarded as typical of an ordinary room), where the standard allows for 35,000,200 particles measuring 0.5 microns, 8,320,000 or fewer particles measuring one micron, and 293,000 or fewer particles measuring five microns, and you can see how carefully a top cleanroom is controlled.
Small amounts of airborne contamination can adversely affect production in certain industries. These sectors include semiconductor production and pharmaceuticals, but cleanrooms are also used in aerospace, defence, and energy to provide a contaminant-free environment. Cleanrooms can also be designed to have precise levels of temperature, pressure, or humidity. Some cleanrooms are designed to be completely sterile.