The Design & Classifcations for Pharmaceutical Cleanrooms


Cleanrooms are used in a broad range of industries to facilitate careful control of environmental factors such as air quality, pressure, temperature, and more. Liberty Industries is an industry leading pharmaceutical cleanroom manufacturer and a global distributor of accessories and supplies. We act as a single source supplier for any cleanroom needs. The quality of our products is matched only by our commitment to customer service.

At Liberty Industries, we’ve provided cleanrooms for customers in an expansive range of industries, including the pharmaceutical sector. Our experienced engineers will gladly customize any of our products to fit the unique needs for any application. With a great deal of experience designing and constructing pharmaceutical cleanrooms, you can be sure that our skilled team will provide a solution.

Designing a Pharmaceutical Cleanroom

A variety of products cannot be manufactured safely outside of a cleanroom. This is especially true for pharmaceutical products, which must maintain strict purity levels. Cleanrooms are designed to carefully control important environmental factors to mitigate the risk of product or sample contamination.

What Kind of Cleanroom Do I Need?

The level of cleanroom cleanliness required for a pharmaceutical cleanroom can vary depending on the product. Some pharmaceuticals are considered to be non-sterile medical products. This means that the cleanrooms used in their production typically only require filtered air and effective ventilation. Conversely, sterile medical products require much stricter environmental controls for their cleanrooms.

corridors for pharmaceutical cleanrooms

Clean and Dirty Corridors

Different product types face separate risks that can be addressed by applying positive and negative pressure to the cleanroom as required;

  • Clean corridors. Pills and tablets made from powders aren’t friendly to microorganisms, but they do pose a risk of cross-contamination between products. As such, most cleanrooms for these products are negatively pressurized to keep powders from drifting out of the room and into other parts of the manufacturing facility. This is known as a “clean corridor” system.
  • Dirty corridors. Cleanrooms for biopharmaceuticals, liquids, or aseptic will be positively pressurized to keep microorganisms from entering the space. This is known as a “dirty corridor” set up.

Of note, doors should always open into the area with the higher pressure to avoid contamination.

Keeping a Cleanroom Clean

There are many processes working in conjunction to maintain the desired environment and cleanliness in pharmaceutical cleanrooms. Some of these include:

  • Air filtration. Air handling systems are designed to maintain enough airflow within the space to keep particulates from settling on surfaces. The higher the cleanliness standards of the cleanroom, the more air must be used for this purpose. HEPA filters and ULPA filters are used to catch these particulates and filter them out of the airflow.
  • Air circulation. Excess moisture in the air of the cleanroom can be detrimental to the viability of many different types of pharmaceutical products. In instances where humidity must be controlled, air handling systems will be designed to recirculate less air. Instead, they supply fresh air into the room to push the moisture safely outside. The same process for removing humidity can also remove toxic elements created from production processes or raw materials.
  • Surfaces. It’s critical that all surfaces in a cleanroom are completely smooth. Microorganisms and other contaminants can build up in cracks and grooves, ultimately impacting the cleanliness of the cleanroom. Surfaces should be easy to wipe down, shouldn’t contain coatings that could peel or crack, and should be resistant to cracking or denting from impacts.

Pharmaceutical Cleanroom Classifications

No cleanroom is 100% free from contaminants. However, cleanrooms are defined by the concentration of particles per cubic meter within the cleanroom environment. ISO 14644-1 is the most widely followed classification system for pharmaceutical cleanrooms, with ISO 1 as the highest level of cleanliness and ISO 9 as the lowest.


The U.S. Food and Drug Administration (FDA) strictly regulates cleanroom use within the United States. FDA rules for cleanrooms are adapted from Current Good Manufacturing Practices (CGMP) regulations. Pharmaceutical manufacturers are also subject to CFR 210 and 211 from the Current Good Manufacturing Practices for Finished Pharmaceuticals. When a rule exists that targets a specific drug product, that rule always supersedes CFR 210 and 211.

  • Design and construction. Regulatory enforcement begins with the design phase of the cleanroom to ensure that the finished product achieves appropriate clean air standards.
  • Monitoring. Beyond the cleanroom itself, the FDA also requires a separate room with monitoring and control equipment for air pressure, dust, humidity, microorganisms, and temperature.
  • Cleanliness levels. The FDA also requires the installation of a compliant air filtration system and written standard operating procedures for cleaning, sanitization, and contamination prevention within the cleanroom.

Ask the Cleanroom Experts

The regulations surrounding the design, construction, and operation of cleanrooms are highly complex. At Liberty Industries, we’ve been in the cleanroom business since our inception in 1953 and we understand all of the rules and challenges involved with installing a new cleanroom.

For more information about our cleanroom solutions or capabilities, please don’t hesitate to contact us or submit a request for information. To learn more about the design and construction of cleanrooms, please download our eBook.


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