Clean Room Standards
Typically speaking, a clean room is used by chemical manufacturers, or those involved with scientific pursuits. It is a space that maintains a low and controlled level of airborne pollutants such as dust, microbes, vapors, and aerosols. Specifically, the area is controlled to contain only a specific number of particles per cubic meter, as well as the size of said particles.
Clean rooms are used wherever airborne particles can adversely affect a manufacturing process. This also includes processes that involve assessing chemical purity. These industries can include, biotech, medical, pharmaceutical, manufacturing, and aerospace operations, among others. The keystone component of these rooms are HEPA certified air filters that are capable of trapping particles within 0.3 microns or larger. For reference the human eye is unable to see anything under 40 microns in size, and a single strand of hair is around 50 microns in diameter. All air that is filtered into a clean room must pass through HEPA air filters, and in cases where standards require it, ultra low particulate air filters can be used. These filters are capable of catching particles as small as 100 nanometres in size. Using the hair example for reference, a typical strand of hair is 100,000 nanometers wide.
Clean Room Clothing
Anyone entering a clean room must be trained to prevent any unnecessary contamination. Personnel must also be properly outfitted with specialized gowns, in addition to going through an airlock, before entering. These gowns are designed to prevent contamination from skin contaminants such as dead skin, or sweat.
Depending on the type of clean room, clothing requirements can vary, from full body suits to simple lab jackets and hair nets. It all depends on the type of process being conducted, and the level of contamination that is acceptable.
Air Flow And Fume Hoods
While the general air is provided from vents and filtered through HEPA filters, other means of controlling air flow are also employed. Fume hoods are used to reduce exposure to chemical mist or vapor that could be harmful if not diluted. Fume hoods are advised to be used whenever hazardous material is being handled. All fume hoods should be tacked with a calibration tag showing what height it should be operated at for maximum effectiveness. Additionally, all fume hoods should be equipped with a monitoring device that provides information about its current status. If a hood is missing a calibration tag, or not displaying correct status information, it should not be used, and the correct maintenance should be conducted.
Clean room Types and Classifications
Clean rooms are ranked in classification based on the quality of the air within. In the United States a clean room is measured by the number of particles greater than or equal to 0.5mm within a cubic foot. Clean rooms are then classified by the number and size of these particles. Larger numbers between 100 and 1000 refer to the number of particles present in the air that are 0.5mm or greater. The smaller the number, such as ISO class 5, the lower the amount of particles per cubic meter allowed within the room.