ISO 14644-1 Standards for Cleanrooms

Cleanroom ISO 14644-1 Standards

The ISO 14644-1 standards were introduced in 1999 due to the need to have a harmonized standard for cleanroom classification and testing. They replaced the US Federal Standard 209E standards. The ISO 14644-1 deals with the classification of air cleanliness in cleanrooms and other controlled environments associated with the cleanroom. The classification is based on the concentration of airborne particulates.
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It is applied to a number of industries such as pharmaceutical, healthcare, medical device production, aerospace production, and food production. The ISO 14644-1 Standard is very common in electronics and pharmaceutical production.

Internal Standards Organization:
14644-1 Cleanroom Standards

There are specific requirements that a cleanroom or clean zone has to meet during periodic tests to prove compliance with the 14644-1 classification. One of the requirements is that cleanrooms should have the capacity to monitor critical parameters and set action and alert alarms. These risk management protocols allow for the establishment of periodic testing schedules for classification.

The air cleanliness in a cleanroom by particle concentration is usually defined by three states of occupancy. They include:

• As-built: They are the cleanest as they don’t have any equipment or human traffic. They are empty cleanrooms that are fitted with running filter systems but yet to be used.
• At-rest: Equipment and products have been added to the room and there’s human access. But at-rest cleanrooms are yet to undergo testing and have a rating of ISO 6.
• Operational: Cleanrooms become operational once they have been tested for performance requirements, benchmarked, and documented. They are used for a given purpose with equipment present and human access given. These are the dirtiest types of cleanrooms as processes and people introduce contaminants.

​The classification of air cleanliness in cleanrooms is summarized in the table below:

Air Cleanliness Class Number	Maximum Concentration Of Particles Per M³ Of Air
	0.1 µm	0.2 µm	0.3 µm	0.5 µm	1 µm	5 µm
ISO 1	10	2
ISO 2	100	24	10	4
ISO 3	1,000	237	102	35	8
ISO 4	10,000	2,370	1,020	352	83
ISO 5	100,000	23,700	10,200	3,520	832	29
ISO 6	1,000,000	237,000	102,000	35,200	8,320	293
ISO 7				352,000	83,200	2,930
ISO 8				3,520,000	832,000	29,300
ISO 9				35,200,000	8,320,000	293,000

Source: ispe.org
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The classification only considers particle populations with cumulative distributions that meet the lower limit for particle sizes. They usually range from 0.1 µm to 5 µm. Light scattering airborne particle counters (LSAPC) are often used to determine the concentration of airborne particles.

It is important to note that the ISO 14644-1 doesn’t cater to the classification of particle populations that don’t meet the lower threshold for particle size range 0.1 µm to 5 µm. A separate standard is used for concentrations of ultrafine particles that are smaller than 0.1 µm. The ISO 14644-1 is also not used for characterizing chemical, physical, viable, radiological, or any other nature of airborne particles.