Have you ever been in a group where you have to cover your entire body before entering the room? Maybe you were made to wear clothing that ranged from a hood, face mask, gloves to overalls and footwear. You would understand if it was a hospital – it’s to protect you and the patients. But why would a pipe manufacturer insist on such a suit?

In fact, there is good reason for companies to use such safeguards. Today we give an overview of some of them, specifically covering clean rooms, contamination, and how companies manage them. 

Clean rooms – An Overview

Small particles can affect the production and quality of many current products. Imagine dust so small you can’t even see it that can render something like an expensive computer chip useless. The same goes for  new  glasses or contact lenses, both of which can become irreversibly scratched from a single speck. Or consider the impact on human health if every new medical device or drug came from a factory full of bacteria and other microorganisms. 

Companies use clean rooms to prevent such possible catastrophes. A clean room (also spelled cleanroom) is an enclosed space in which certain environmental parameters or factors are precisely monitored, contained, and controlled. 

Many industries are well-known to use clean rooms:

  • Aerospace
  • Automotive
  • Bio-tech
  • Life sciences
  • Medical device
  • Military
  • Optics
  • Pharmaceutical
  • Semiconductor

Many companies use clean rooms simply to meet FDA cleanliness and sterility requirements. But clean rooms also prove useful in improving process consistency and part quality, and thus guaranteeing the cleanliness of the finished product.

Clean room Contamination Classification

Many clean room designs are dedicated to contamination control. 

“Contamination” is broadly defined as anything that can taint a product or process simply by touching or mixing it. (The dust mentioned above is a good example.) 

Contaminants come in many forms. They can be solids, liquids, or gas, with particles suspended in air, transported along surfaces, or liquid-based. Static electricity can be a contaminant in certain industries such as semiconductor chip manufacturing.

The main source of contaminants are people. Specifically:

  • Clothing debris
  • Hair
  • Perspiration
  • Saliva
  • Skin flakes and oil

Many common goods are sources of contamination. Duct tape, cardboard, pencils, drywall, and paint shed contaminates through various forms like threads, shavings, and flakes. 

So how do companies know how much contamination is present in a particular space? For clean rooms, contamination is measured by the number of particles per cubic meter or feet of air at a specified particle size. The ambient air in a typical city, for example, contains approximately 35,000,000 particles per cubic meter with each particle measuring 0.5 micron and larger in diameter. 

The ISO (International Organization for Standardization) established the standards for cleanliness in clean rooms. It is provided in the document, ISO 14644-1. 

ISO Class 9 has the most contaminants per cubic meter and the largest particle size. The city above is an example of ISO Class 9. 

Most clean rooms are ISO 8 and 7.  

An ISO Class 1 has the fewest particles (10 particles per cubic meter) and smallest size (half a micron). Few industries outside of the life sciences and electronics requiring nanotechnology have or use such rooms. 

Note that in some industries, clean rooms are also built to contain and/or prevent certain contaminants from going outside as well (e.g., dangerous viruses and nuclear material). 

Containment Control by Clean rooms

Clean rooms use several methods to minimize contaminants.

  • Surfaces within the room like the walls and floor should be smooth and made of material impervious to microorganisms. They should also be compatible with the approved cleaning agents and disinfectants.
  • Clean room air is circulated by HVAC systems using HEPA (High Efficiency Particulate Air) filters. 99.99 percent of particles that are 0.3 micron and larger in size are blocked by such units. Ultra Low Particulate Air (ULPA) filters are available for even more stringent cleanliness (ISO Class 1).
  • Air pressure should be greater inside the clean room than outside. Called “positive pressure”, this technique pushes the contaminated room air through vents to the outside. It is then filtered and brought back in and recirculated. The “cleaner” a clean room needs to be, the more air exchanges per hour is required to meet classification standards. 
  • Clean room temperature and humidity levels are controlled to reduce microbial growth like viruses, spores, fungi, and bacteria. Controlling humidity also reduces the chance of static electricity. 
  • Staff are given and trained to wear approved gowns, hairnets, gloves, overshoes, and other protective gear when entering – and exiting – the clean room. This helps to cut the chance of introducing bacteria and other contaminants. Essential behavioral standards like how to properly sneeze while in the cleanroom need to be followed.
  • ISO 8 and cleaner (7, 6, etc.) will need airlocks for employees and equipment when entering and exiting. 
  • Equipment like computers used in clean rooms should have many of the above properties. Industrial mini PCs or medical tablets, for example, in the room should be sealed IP65 to withstand the special cleaning agents and disinfectants during cleaning. They should also be fanless in order not to interfere with the clean room’s special air circulation systems. 

Closing Comment

A clean room is a special enclosed space designed to control contaminants within it. Companies like KDF Electronics use clean rooms in any processes where cleanliness is paramount in their processes or customers (i.e., healthcare). 

Contact an expert at Cybernet if your company uses clean rooms and what’s the best computers to use within them. 

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