Cleanroom: Definition, Structure, ISO Classes

A cleanroom is a controlled environment designed to reduce the presence of airborne particles and other contaminants. It is used in a variety of industries, including pharmaceuticals, biotechnology, electronics, and aerospace.

The structure of a cleanroom typically includes a system of filters and air handlers that circulate and filter the air. The room itself is constructed of materials that do not shed particles, and personnel are required to wear special garments that help minimize the shedding of particles from their bodies.

Cleanrooms are classified according to the number and size of particles allowed per cubic meter of air. This classification is determined by the International Organization for Standardization (ISO) and is denoted by a number from 1 to 9. The lower the ISO number, the cleaner the room. Here are the ISO classes and their respective particle limits:

• ISO 1: <10 particles per cubic meter (0.1 micron or larger)
• ISO 2: <100 particles per cubic meter (0.1 micron or larger)
• ISO 3: <1,000 particles per cubic meter (0.1 micron or larger)
• ISO 4: <10,000 particles per cubic meter (0.1 micron or larger)
• ISO 5: <100,000 particles per cubic meter (0.1 micron or larger)
• ISO 6: <1,000,000 particles per cubic meter (0.5 micron or larger)
• ISO 7: <10,000,000 particles per cubic meter (5 micron or larger)
• ISO 8: <100,000,000 particles per cubic meter (5 micron or larger)
• ISO 9: <1,000,000,000 particles per cubic meter (5 micron or larger)

In addition to particle counts, cleanrooms are also monitored for temperature, humidity, and other environmental factors to ensure that they meet the necessary specifications for the particular process being carried out in the cleanroom.