Cleanroom Basics

A modular cleanroom is a cleanroom that is made from prefabricated parts that are then assembled on-site. They use negative pressure plenum design to reduce cost and are easily reconfigurable for future needs.

Modular cleanrooms offer faster installation, are available for ISO-5 thru ISO-8 cleanroom classifications, and can be used for all industries: medical device, pharmaceutical, electronics, aerospace, industrial and government. Modular cleanrooms are comparable in cost to standard constructions and can be permitted.

ISO-14644-1 and FEDSTD 209e set the particle counts and HEPA air changes per hour required for ISO-5 thru ISO-8 or class 100 thru class 100k cleanrooms.

ISO cleanroom classifications measure particle counts per cubic meter. ISO cleanroom standard is used most commonly in pharmaceutical and medical devices industry. The electronics industry still uses FED Std 209E which measures particles per cubic feet.

Cleanrooms rely on HEPA (high efficiency particulate air) filters to keep the air clean. The recirculating design means the HEPA fan filter units keep recleaning the clean air resulting the lowest possible particle counts. Dedicated air conditioning and humidifiers/dehumidifiers are used to hold the extremely tight temperature and humidity tolerances required for semiconductor, battery, and pharmaceutical industries.

Modular cleanrooms offer material and equipment options for ESD control. Modular cleanrooms can be installed much faster than standard construction. Modular cleanrooms are easily modified.

Cleanrooms use HEPA fan filter units to remove contamination from the cleanroom. By increasing the number of air changes per hour we remove more of the particles. The higher number of air changes per hour the higher the cleanroom classification (and lower number of particles). Humans are the largest source of contamination in a cleanroom so personnel must wear cleanroom garments to encapsulate human particles and prevent them from entering the cleanroom. Regular cleaning is another way to control contamination in the cleanroom.

Cleanroom air quality standards are limits on size and quantity of non viable particles per ISO-14644-1 cleanroom classifications. Viable particles standards are limits per pharmaceutical and medical device FDA validation documents.

People typically monitor differential pressure, temperature, and humidity in a cleanroom environment. Differential pressure confirms that HEPA filtration is working correctly to keep cleanroom clean. Temperature confirms that AC is working to keep cleanroom cool. Humidity to confirm that humidifier and/or dehumidifier is working to keep room at humidity specification.

Cleanroom validation is part of FDA required drug validation process for CGMP (Current Good Manufacturing Practice). The cleanroom validation process includes design qualification, installation qualification, operational qualification and performance qualification.

As built particle testing is used to certify that the cleanroom meets ISO class. The cleanroom is tested via ISO 14644-1 by taking the prescribed number of particle measurements in each room. The air changes per hour can be computed by comparing the volume of each room vs. the number of HEPA fan filter units or by physically measuring air flow thru each. Finally differential room pressure is measured via Magnehelic gauges. Cleanroom validation requires Design Qualification, Installation Qualification, Operational Qualification, and Performance Qualification.

Cleanroom cost depends on size, classification and type of cleanroom. Higher rated ISO-5 cleanrooms cost more than ISO-8 cleanrooms due to large number of HEPA fan filter units and higher AC requirements. For cleanrooms with high heat loads or large exhaust cfm the AC can make up to 40% of the cost of the cleanroom project.

Modular cleanroom ROI is the Return On Investment by choosing a modular cleanroom over a stick built (standard construction) cleanroom. Significant cost savings include faster installation, lower cost, easy modifications, can be moved to new location, superior tax treatment, and longer life.

Pharmaceutical and medical device cleanroom requirements come from customer product/cleanroom validation document. That document is required by the FDA CGMP (Current Good Manufacturing Practice) to get approval for the medical device or pharmaceutical product. Industrial cleanrooms are not regulated but conform with ISO 14644-1 and FEDStd 209E cleanroom classifications.