Air shower is also known as clean air shower room, purified air shower room, air shower room, air shower door, dust bath room, shower room, air shower channel and air shower room. The air shower room is the necessary access to the class 10000 clean room, which can reduce the pollution problems caused by entering and leaving the clean room. Air shower is a kind of local purification equipment with strong universality, which is installed between class 10000 clean room and non clean room. When people and goods want to enter the clean area, they need to be blown through the air shower room. The clean air blown out can remove the dust carried by people and goods, which can effectively block or reduce the dust source from entering the clean area. The front and rear doors of the air shower / cargo shower room are electronically interlocked, which can also act as an air lock to prevent the raw air from entering the clean area.

An ISO 7 clean room, also known as a Class 10000 clean room, is a rigidly constructed facility equipped with HEPA filtration systems to maintain air cleanliness at a maximum of 10,000 particles (≥0.5µm) per cubic foot. The ideal relative humidity (RH) range for this standard class is between 30-40%. Airborne contaminants are measured in terms of the maximum particles per cubic foot. Therefore, a "Class 100" environment indicates an upper limit of 100 particles/ft3, sized at 5 µm or smaller. Similarly, a "Class 10" denotes no more than 10 particles/ft3.

For an ISO 8 or Fed-Std 209E cleanroom to meet class 100,000, there must be 3,520,000 particles per cubic meter or less of 0.5 m diameter, 832,000 particles per cubic meter or less of 1 m diameter, and 29,300 particles per cubic meter or less of 5 m diameter.

Cleanrooms are enclosed, virtually pollutant-free spaces. They are also needed for the production of precision electronics and aerospace equipment.

ISO Standard 14644 describes the air quality for cleanrooms. An older reference is the Federal Standard 209 E “Airborne Particulate Cleanliness Classes in Clean Rooms and Clean Zones.” 

It is now withdrawn, but the standards overlap with ISO levels. The classes refer to the acceptable maximum number of particles that are 0.5 micrometers or larger in diameter.

It is forbidden to contain more than 352,000 particles of more than 0.5 micrometers in a class 10000 cleanroom (also called ISO 7) per cubic meter. Air changes per hour are also a criterion for a cleanroom. The air in a cleanroom is exchanged 60 to 750 times per hour with filtered outside air.