ISO 14644 cleanroom standards for data centers

A brief history of ISO 14644

The first version of ISO 14644 is similar to the 1999 U.S. Federal Standard 209E Airborne Particulate Cleanliness Classes in Cleanrooms and Clean Zones standard. The federal standard was discontinued in 2001 and superseded by ISO 14644.

ISO 14644 evolves with industries. In 2001, this standard was only one part. The evolution of ISO 14644 totaled four parts in 2015, 10 parts in 2019 and over 20 parts in 2023. To keep the standard relevant, experts in the field update previous parts and add new ones when necessary. The latest version covers design, airborne particle sampling techniques, separative devices and energy efficiency.

Parts of ISO 14644 for data centers

While ISO 14644 contains over 20 parts that are relevant to situations where controlled environments are necessary, this section will focus on up through Part 14.

Part 14644-6 and 14644-11 are not included as Part 6 was withdrawn by ISO/TC 209 and Part 11 does not exist.

Part 14644-1: Classification of air cleanliness by particle concentration

Part 14644-1 specifies the classification of air cleanliness by airborne particle concentrations in cleanrooms and clean zones as well as for separative devices as defined in ISO 14644-7. It outlines the classification to characterize environmental cleanliness in areas like data centers from Class 1 to Class 9.

ISO Class 1 environments are the cleanest environments like those found in silicon chip clean rooms. Classes 7 and 8 are the most appropriate for IT facilities like data centers and server rooms.

Part 14644-2: Monitoring to provide evidence of cleanroom performance related to air cleanliness by particle concentration

Part 14644-2 specifies the monitoring and testing requirements for cleanrooms and clean zones. It outlines the minimum requirements for a monitoring plan based on parameters that measure or affect airborne particle concentration.

To meet this requirement, data centers must use either sequential, continuous or periodic air monitoring. For example, with periodic monitoring, the facility must clearly specify the test frequency when proving compliance with the standard.

Part 14644-3: Test methods

Part 14644-3 specifies the test methods that support the operation of the controlled environment to meet the relevant air cleanliness classification, attributes and related conditions.

Test methods depend on the airflow characteristics and occupancy states of the controlled environment. Data centers fulfill multiple airflow and occupancy states at various times. Operators should read this standard carefully to ensure they are compliant.

This ISO standard has not been approved as an American National Standard.

Part 14644-4: Design, construction and start-up

Part 14644-4 specifies the process for creating a cleanroom or controlled environment from design, construction and startup. It applies to new, refurbished and modified installations but does not prescribe specific technologies or methods to achieve the requirements. Each location can use any methods, technology, mechanics and designs to meet the standard.

Data center builders, maintainers and owners can use the ISO 14644 checklist to ensure satisfactory operation for the entire lifecycle of the data center or controlled environment.

Part 14644-5: Operations

Part 14644-5 specifies the basic requirements for cleanroom and controlled environment operations. Since it considers all classes of controlled environments, it is broad in application and doesn't address specific requirements for individual industries. Data center operators must apply this standard as appropriate to their facilities.

Data center operators should review this standard to ensure their operational systems, personnel rules, equipment and cleaning schedules are in compliance. This only applies to contamination control.

This part does not include aspects of national, local and industry-related safety regulations that must be under observation in the controlled environment.

Part 14644-7: Separative devices (clean air hoods, gloveboxes, isolators and mini environments)

Part 14644-7 specifies the minimum requirements for the separative devices in use in the controlled space. It outlines the approval, construction, design, installation and testing of the devices in use in cleanrooms and other controlled environments like data centers.

Data center operators should review this standard to ensure they are using the relevant devices that help them conform to the standard.

This part does not include requirements by national, local and industry-related safety regulations, such as fire.

Part 14644-8: Assessment of air cleanliness for chemical concentration

Part 14644-8 establishes the assessment processes for grading levels of air chemical cleanliness (ACC) in controlled environments according to specific concentration categories: individual, group or category. It provides a protocol for testing methods, analysis and time-weighted factors that affect the determination.

This part does not apply to industries, processes or productions not put at risk by the presence of ACC. This means it might or might not apply to data centers, as it depends on the equipment, location and workloads it handles.

Part 14644-9: Assessment of surface cleanliness for particle concentration

Part 14644-9 establishes a particle cleanliness level assessment for solid surfaces in controlled environments. It applies to all solid surfaces in the controlled environment, such as walls, ceilings, floors, equipment and tools.

Data center operators should pay attention to this standard to ensure their facilities and operations meet it.

This part does not outline cleanliness requirements or surface suitability for specific industries, processes or procedures. It also does not consider material characteristics for items within the controlled environment.

Part 14644-10: Assessment of surface cleanliness for chemical contamination

Part 14644-10 establishes the cleanliness testing processes of surfaces which contain chemical compounds or elements. It is also applicable to all solid surfaces in the controlled environment, such as walls, ceilings, floors, equipment and tools.

This part would generally only apply to data centers located close to production or manufacturing facilities, but organizations should monitor it for each data center location as a precaution.

This part does not include aspects of national, local and industry-related safety regulations that must be under observation in the controlled environment.

Part 14644-12: Specifications for monitoring air cleanliness by nanoscale particle concentration

Part 14644-12 covers how to monitor air cleanliness of airborne nanoscale particles. It covers particles with a lower size limit of 0.1 microns or less and is mainly in use in operational facilities.

This part is intended to support nanotechnology research, development and manufacturing. It might not apply to data centers unless they are located near or support these industries.

This part does not include aspects of national, local and industry-related safety regulations that must be under observation in the controlled environment.

Part 14644-13: Cleaning of surfaces to achieve defined levels of cleanliness in terms of particle and chemical classifications

Part 14644-13 offers guidelines for cleaning surfaces -- equipment and material surfaces -- in a controlled environment to a specific degree. It applies to all external or internal surfaces that are of interest within the environment.

It provides guidelines for assessing the cleaning methods for achieving the appropriate cleanliness level and surface cleanliness by chemical concentration class. It also offers techniques facility operators should consider to achieve these cleanliness levels.

Data center operators and facility managers should refer to their equipment's documentation for more details on processes, methods and products to use.

Part 14644-14: Assessment of suitability for use of equipment by airborne particle concentration

Part 14644-14 specifies a methodology that relates to the air cleanliness classification by particle concentration to assess the suitability of the equipment.

This applies to data centers and relates to any equipment that people bring, unbox and install in the facility along with tools and equipment to perform regular activities.

This part does not include aspects of national, local and industry-related safety regulations that must be under observation in the controlled environment.

Julia Borgini is a freelance technical copywriter and content marketing strategist who helps B2B technology companies publish valuable content.