Cleanrooms are typically used in every industry, mostly in the manufacturing sector or scientific research, in which small particles can adversely affect the manufacturing procedure. A cleanroom is an administered environment that has lower levels of pollutants such as airborne microbes, chemical vapours, aerosol particles, and dust.
A cleanroom is any controlled, contained space where provisions are made to manipulate the environmental conditions such as humidity, air pressure, dust particles, and the temperature. Cleanrooms have a controlled level of pollutants that is identified by the number of particles per cubic meter at a particular particle size.
The key component of any cleanroom is HEPA (High-Efficiency Particulate Air) filter that is used to trap particles of 0.3 microns and is larger. The air passes through this HEPA filter every time it enters the cleanroom. The Ultra-Low Particulate Filters (ULPF) are used where strict cleanliness is necessary to perform any task.
The team working in the cleanrooms undergo extensive training in contamination control. They enter or exit the cleanrooms, through airlocks, air showers, or gowning rooms. They also wear specially designed clothes that are made to trap any pollutant, contamination that is generated by the human body.
Cleanrooms differ in size and intricacy and are used for different industrial purposes such as in the pharmaceutical industry, manufacturing industry, biotech, life sciences as well as analytical industries such as aerospace, military, medical devices, department of Atomic Energy, etc.
Cleanroom Garments are another important thing that has to be taken care of. Depending on the complexity of the environment, it may sometimes be limited to coats and hairnet. It sometimes may require wearing layers and layers of suits and masks to prevent the contamination from the body to affect the environment in any way.
Classification of Cleanrooms and Cleanroom Standards
The cleanliness of the air fundamentally tabulates cleanrooms. The method, as suggested earlier in the Federal Standards 209 in which air particles equal to or higher than 0.5 mm measured per cubic feet of air, is used to classify the rooms. 209E Federal Standards, the most recent version, also accepts the same metric nomenclature.
The cleanroom classification standards FS 209E and ISO 14644-1 uses a specific count of particles for accurate measurements and calculations to classify any clean area. Large numbers like class 1000 refer to FED_STD-209E and denote the number of larger particles permitted per cubic foot of air.
Small numbers represent ISO 14644-1 standards, which denote the number of particles as 0.1 mm or larger permitted per cubic meter of air. So if we’re categorizing IOS class 4, the cleanroom has a class 10 equivalent of FED STD 209E.
The classifications thus cover particles ranging between 0.1-0.5 microns. Also, the ultrafine microparticles that use the ULPF are described by U descriptors and M descriptors, respectively, for the <0.1 microns and microparticles>0.5 microns. There are three fundamental occupancy states, namely, “as-built,” “at rest,” or “operational.”
Although the final user of the room would only be concerned with the “operational” part, the “at rest” and “as-built” are equally essential to classify abnormalities or problems related to any cleanrooms.
These standards are prepared and approved by the experts at the international level and have started taking over the national standards set by different countries. The national and industrial guidelines now cover only specific applications today.
If one has to classify normal rooms as per the IOS standards, it would be categorized as IOS standard 9 because of the fine particles, dust, airborne microbes, and chemical vapours, which are not ideal for any important industrial manufacturing or equipment.