What is a cleanroom?

Cleanrooms focus on several factors to create an environment that is free of contaminants. This is achieved by monitoring and maintaining:

  • Control of the contaminants in the air
  • Pressurisation
  • The temperature and humidity
  • Restricted access

What are cleanrooms used for?

Cleanrooms are utilised by the scientific, pharmaceutical and, more recently, food sectors, among others to ensure the highest levels of hygiene when carrying out essential works. Any industry where small particles can hurt manufacturing processes will benefit from the use of a controlled environment such as a cleanroom.

How does a cleanroom work?

Cleanrooms are designed to ensure extremely low particulate levels, including airborne organisms, dust and vaporised particles, are maintained at all times.

These particulates are naturally carried throughout the air but can be hazardous to certain processes. For example, when processing meat or dairy products, limiting the amount of bacteria in the preparation area is vital to ensure the safety of consumers.

High Efficiency Particulate Air filters (HEPA) and Ultra Low Particulate Air Filters (ULPA) ensure that the air within a designated cleanroom or space is free of particulates.

Cleanroom classifications

The ISO set out specific classes of cleanrooms depending on their function. The class a function falls under will outline the required air change each hour along with details regarding air cleanliness by particle concentration and airborne particulate contamination limits.

What is contamination in a cleanroom?

Contamination refers to anything that can make a product or process impure, whether that be from touching or mixing the product or process. Contaminates within a cleanroom can take the form of:


Individuals are the primary source of contamination, whether through the shedding of skin cells, oils or hair, through saliva, perspiration or debris from their clothing. This is why any personnel required to work within a cleanroom must be highly trained and wear protective equipment, including masks and glasses, suits, gloves and shoe covers. The clothing required will depend on the function of the space. It is also essential that access to the area is limited to prevent further contamination.

Air contamination

Air contamination is a significant problem when operating a cleanroom as the particles are small enough to float in the air for a considerable amount of time. Continual filtration of these particles is required for the space to remain safe enough to continue with production or completing processes.

Process chemical and gas contamination

Large quantities of chemicals are utilised within cleanrooms, depending on the function of the space. To combat the risk of contamination from these chemicals, delivery in non-corrosive, clean containers are necessary, along with clean transportation.

Any gasses utilised must only be filtered to reduce particulate levels and be of the highest quality possible. It is also vital to consider vapours or byproducts of the gasses used and how these may react with the area to produce unwanted contaminants.

Water contamination

Water is mainly utilised in the cleaning process within a cleanroom. Many manufacturers treat the water before using it to remove contaminants that may be present such as:

  • Dissolved salts and minerals
  • Bacteria and organics
  • Particulates

Equipment and consumables

Any equipment brought into the cleanroom could contaminate the area. Therefore, all equipment must be manufactured to strict guidelines and everything within the space must be effectively cleaned with wipes and disinfectants specially made for cleanrooms.

How is contamination within a cleanroom measured?

By measuring the number of airborne particles present within a cubic meter of air, a cleanroom can measure the level of contamination present. Airborne particles are measured in microns, with a single micron being thinner than a strand of hair.

For more information and news stories surrounding cleanrooms, refer back regularly to the cleanroom category within the Scientist Live website.


Link to food industry cleanroom piece when it is live


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