Clean Room refers to a controlled environment that is specially designed to minimize the introduction, generation, and retention of particles, contaminants, and other unwanted elements. These facilities are widely used in industries such as electronics manufacturing, semiconductor production, pharmaceutical research, and healthcare. In a clean room, the air quality is strictly regulated by removing pollutants such as dust, airborne microbes, aerosol particles, and chemical vapors. The cleanliness level is measured by the number of particles per cubic meter in the specified size range.

Clean Room Components and Design

HVAC System

The Heating, Ventilation, and Air Conditioning (HVAC) system plays a crucial role in maintaining the desired cleanliness level in a clean room. It provides a controlled environment by filtering and circulating air through the space. The HVAC system removes contaminants present in the outside air while maintaining appropriate temperature and humidity levels.

Air Filtration

Clean rooms employ high-efficiency particulate air (HEPA) filters to remove sub-micron particles from the air supply. HEPA filters are capable of removing up to 99.97% of particles down to 0.3 micrometers in size. These filters are typically pleated and made from fiberglass with an aluminum or plastic frame.

Pressure Differential

Clean rooms are designed with pressure differentials to prevent contamination from adjacent areas or entry points. The pressure differential ensures that air flows from cleaner areas to less clean areas. Positive pressure is maintained for critical environments like semiconductor fabrication facilities to prevent unfiltered air from entering through cracks or door openings.

Clean Room Suits

To further minimize particle generation from human operators entering the clean room, personnel wear specialized garments known as clean room suits or bunny suits. These suits include coveralls, hoods, gloves, masks, and shoe covers made from lint-free materials that reduce particle shedding.

Clean Room Classification Standards

Clean rooms are classified based on the maximum permitted number of particles and the particle size that can be present in a cubic meter of air. The classification standards vary depending on the industry and application, with ISO, US Federal Standard 209E, and EN 14644 being some commonly used standards.

ISO Standards

The International Organization for Standardization (ISO) has established clean room classification standards known as ISO 14644. The ISO classifications define the maximum allowed number of particles for specific particle sizes.

US Federal Standard 209E

The US Federal Standard 209E was one of the earlier clean room classification systems used in various industries. It specified cleanliness levels based on the number of particles per cubic foot for specific particle sizes.

EN 14644

The European standard EN 14644 is commonly used in Europe and other parts of the world. It specifies classes A to D for cleanliness levels, with class A being the strictest in terms of permitted particulate contamination.

Applications of Clean Rooms

Clean rooms find applications across diverse industries where maintaining a controlled environment is crucial. Here are some examples:

Electronics Manufacturing

In electronics manufacturing, particularly microelectronics, clean rooms are necessary to prevent dust, moisture, and other contaminants from affecting the delicate components. Clean rooms help ensure high-quality production processes for electronic devices by reducing defects caused by particles or chemical impurities.

Pharmaceutical Industry

The pharmaceutical industry relies heavily on clean rooms to maintain sterile environments essential for drug manufacturing, research laboratories, compounding pharmacies, and hospitals. Clean rooms play a critical role in preventing airborne contamination that could compromise the safety and efficacy of medical products.

Biotechnology Research

Biotechnology research facilities use clean rooms to prevent cross-contamination between different cell cultures or genetically modified organisms (GMOs). The controlled environment minimizes the risk of contamination that could affect experimental results or compromise biological samples.

Aerospace Industry

In aerospace manufacturing processes such as satellite assembly or spacecraft fabrication, clean rooms are utilized to prevent contamination that could compromise the performance of sensitive components or instruments. The removal of particles and control over environmental factors is crucial for the reliability and longevity of aerospace equipment.


Clean rooms are essential in industries where contamination control is vital. Strict regulations and standards govern their design and operation. By maintaining a controlled environment, clean rooms ensure high levels of quality, safety, and reliability in the products and processes associated with the industry that utilizes them. Whether it’s electronics manufacturing, pharmaceutical research, biotechnology or aerospace industry – clean rooms provide the necessary conditions for success.