Design and Build

A cleanroom is a controlled environment, utilized in scientific research, Pharmaceutical production, semiconductor manufacturing and a few other fields. The purpose is to filter the air and the environment off the pollutants such as dust, microbes, chemical vapors, or generally any particle that could jeopardize a process and product or possess health issues to the personnel.

Achieving above requires further classification based on the required specification and application field. ISO 14644-1 however, has provided the following
classification according to the size and number of aerosol particles disregarding their attributes.



While the class of “cleanliness” is dictated by the standards and industry in different fields, designing and building a cleanroom requires many other factors crucial to the success of the result. A common and typical use of cleanroom is for compounding Pharmacies supervised by different regulatory bodies and standard organizations. USP (United States Pharmacopeia) is the main organization defining the standards and regulations in United States.

Specifically, USP 797, and USP 800 are defining the standard and quality for “pharmaceutical compounding – sterile preparation” and “hazardous drugs – handling in health care settings” respectively. Both 797 and 800 chapters have gone through extensive review and development for the past couple of years. In the light of current changes in USP 797 and 800, NAPRA (National Association of Pharmacy Regulatory Authorities) the Canadian equivalent, has offered its own set of revised and extended model standards for hazardous and non-hazardous sterile preparations as well as non-sterile hazardous preparations. In specific case of Canadian compounding pharmacies, it is noteworthy that it is the provincial college of pharmacist that decides and execute which standard and what requirement will be enforced.

Although the FED USD 209E has been canceled, its classifications is still widely referred to in the industry.

Above short description is meant to Segway into other crucial factors in design and building of a cleanroom.

Protecting Personnel or process/product plays a role in defining the pressure of cleanroom in comparison to the adjacent rooms. This idea is also closely related to, as if it’s the other side of same coin, whether the subjected process/product is hazardous or non-hazardous.

+/- Pressure


ACH & Air Velocity

High efficiency particulate air (HEPA) and ultra-low particulate air (ULPA) filters are designed to filter particles in air. HEPA is capable of filtering 99.97% of particles 0.3 μm or larger in diameter. ULPA can filter 99.999% of particles 0.12 μm or larger in diameter. These filters often (but not in all application) come with fan/blower making the package a fan filter unit (FFU). Air is either pushed or drawn through the filter with the blower equipped with multi speed or smart electronic commutator motors. The reason for changeable speed brings us to one of the most important factors in cleanroom construction.

ACH (Air change per Hour)/Airflow velocity While application of either HEPA or ULPA filters play a role in removing the air particles, more important in defining the class of cleanliness is the number of room air change per hour and the airflow velocity. Hence the higher number of air change per hour, the “cleaner” the room.

The table showing ACH requirements is to shed more light on the idea.

Once again depending on the application and industry the temperature and humidity requirements may differ. As an example both USP 797 and NAPRA standards call for a recommended temperature of 20 C or less, taking into account the comfort of personnel who are fully gowned. As for humidity, while there is no concrete and agreed upon values for pharmaceutical compounding, it is an important factor when it comes to semiconductor manufacturing processes or specific scientific research.

At Stellartec Solutions we don’t assume. We look into every detail, every requirement and walk you through this from the beginning to the end.