Introduction
ISO 14644 is a standard for cleanrooms, developed by the International Standards for Organisation (ISO). The ISO has been in existence since 1947 after 65 delegates from 25 different countries met to discuss its future the previous year. They saw the need to set up a non-governmental body, with the sole purpose of determining best practices for different industries. To this day, these practices are still in operation, and cleanrooms and contamination control fall under the ISO umbrella.
While many countries have their own set of guidelines, rules, regulations, and classifications, ISO 14644 is considered the gold standard for cleanrooms internationally. Many countries’ guidelines build on, coincide with, or reference ISO 14644. This is because ISO 14644 is both exhaustive and informative. It goes into detail about what a cleanroom should look like, how it should be run, and more.
In the chart below these sections are referred to in a very specific way. For example, ISO 14644-1:2015 means it is referring to Section 1 of the 2015 version of ISO14644. As of the publication of this blog, 2015 is the most recent version of ISO 14644.
ISO14644 – Section 1:2015 Classification of Air Cleanliness
This is the first part of ISO 14644 and the foundation of it all: ISO classifications. By maintaining this classification, you will communicate how clean your cleanroom is.
This classification is based on the concentration of air particles in a cleanroom based on an analysis carried out in various parts of a cleanroom, with an average of the particle concentrations totals and their sizes. There are 9classifications, with ISO 1 being the cleanest and ISO 9 being the regular air room.
Particle sizes and concentrations should be determined using a light-scattering airborne particle counter.
ISO14644 – Section 2:2015 Specifications for Testing and Monitoring
The second portion of ISO 14644 outlines the minimum requirement for monitoring a cleanroom. It places an emphasis on continuous monitoring, which allows for a better overall picture of a cleanroom's cleanliness, versus the occasional monitoring favoured in some cleanrooms.
To develop a monitoring plan, ISO 14644-2:2015 also dictates having a strategic risk assessment.
ISO14644 – Section 3:2015 Metrology and Test Methods
In the third portion of ISO 14644, you will find the requirements for testing methods that support your cleanroom operation and cleanliness levels to maintain your classification. These test methods are based on your airflow strategy. There are two types of airflow specified: unidirectional and non-unidirectional.
You will also need to test in three states: as-built, at-rest, and operational. This section defines those states, recommends different tools to test with, and exactly how to conduct the procedures. If you wish to classify and maintain that classification, you will need to follow the testing methods put forward in this section.
The following graphic depicts a leak test in an ISO 14644-3 defined filter.
ISO14644 – Section 4:2001 Design, Construction, and Start-Up
You will notice that the most recent version of the fourth section of ISO 14644 is from2001. It specifies how you should design and construct your cleanroom. True contamination control starts at this level, so it is very important to be familiar with this section. Guidelines are also provided along with start-up and qualification requirements.
ISO14644 – Section 5:2004 Operations
If you are an operational manager, the fifth section of ISO 14644 is for you. It outlines how to plan and use the operations of a cleanroom.
This is a rather broad section, as it may be used in several industries, therefore, it is important to ensure you are familiar with the safety needs in your cleanroom, as well as national and local safety regulations.
ISO 14644-2 and ISO 14644-3 are also referenced but not covered in detail. To make the most of this section, you should be fully familiar with both.
ISO14644 – Section 6:2007 Vocabulary
The sixth section of ISO 14644 is very straightforward: it defines the vocabulary used in the guidelines.
ISO14644 – Section 7:2004 Separative Enclosures
Depending on the industry, ISO 14644-7 will be interpreted differently. The term “separative enclosures” broadly refers to a multitude of configurations. This could include air hoods, gloveboxes, isolators, and mini environments. These are contraptions that put a barrier between the human and the contents. They provide varying levels of protection through physical or dynamic barriers. They could also require a special atmosphere.
These are typically structures within a cleanroom: not a separative environment. They could be mobile or a fixed space in the cleanroom. They have a variety of uses, so, this section must be very wide-reaching in its definitions.
In general, ISO 14644-7 defines “the minimum requirements for the design, construction, installation, test and approval of separative devices, in those respects where they differ from cleanrooms as described in ISO 14644-4and 14644-5.”
ISO14644 – Section 8:2022 Assessment of Air Cleanliness for Chemical Concentration
ISO14644-8 is a cleanroom standard focusing on airborne molecular contamination(AMC), setting classifications and concentration limits for specific chemical contaminants like acids, bases, and volatile organic compounds that can affect sensitive environments. This standard is vital in industries such as semiconductor manufacturing, pharmaceuticals, and aerospace, where even trace chemical contaminants may compromise product quality and safety. By establishing acceptable levels of AMCs and detailing precise monitoring and measurement techniques, ISO 14644-8 helps ensure ultra-pure air quality, enabling optimal production conditions and reducing contamination risks in highly controlled environments.
ISO14644 – Section 9:2022 Classification of Surface Cleanliness by Particle Concentration
ISO14644-9 addresses surface cleanliness in cleanrooms and controlled environments by setting standards for particle contamination on surfaces, complementing the airborne particle standards in other parts of the ISO 14644 series. This standard defines classes of surface particle cleanliness (SPC) based on the size and concentration of particles on surfaces, as well as methods for sampling and measuring surface contamination. It is essential for industries such as microelectronics, aerospace, and pharmaceuticals, where surface contamination can directly impact product integrity and quality. ISO 14644-9enables these industries to maintain rigorous cleanliness standards, reducing risks of defects and ensuring higher quality control.
FEDSTD 209E
Fed Std209E was defined by the United States Government in 1963. It was officially discontinued in 2001 but is still used in industry. There is a close correlation between ISO-14644-1 cleanroom classes and FED Std 209E cleanroom classes. The primary difference is that ISO-14644-1 lists particles per meter cubed (m3) and Fed Std 209E lists particles per feet cubed (ft3).
CONCLUSION
Understanding ISO 14644 class 1-9 and Federal Standard 209E cleanroom classifications is critical for industries that demand controlled environments, from semiconductor manufacturing to pharmaceutical production. Each classification defines strict particle count limits to ensure product integrity, safety, and regulatory compliance.
Selecting the right cleanroom class depends on factors like airborne particle requirements, application needs, and industry standards. Whether you need an ISO Class 1 environment for nanotechnology or an ISO Class 7 cleanroom for medical device assembly, investing in the correct classification ensures efficiency and compliance.
At Patina, we provide specialised cleanroom lighting solutions designed to meet the most stringent requirements. We have a deep understanding of cleanrooms and the high-level requirements necessary. Ensuring fittings are completely sealed prevents particle ingress. LED luminaires also generate low thermal output, which prevents thermal fumes from disrupting the movement of filtered air. ISO14644 ensures that lighting does not interfere with cleanroom airflow, which is essential for maintaining a controlled particle flow. The high quality of our lighting designs reduces maintenance-related contamination risks. Fewer disturbances mean fewer particles introduced into the cleanroom. Long-lasting LED fixtures with high IP ratings reduce the need for frequent replacements, minimising disruptions.
By choosing ISO 14644-compliant lighting, manufacturers can maintain the highest standards of cleanroom performance, safety, and efficiency.
