Cleanroom classification can be confusing, especially when there are multiple standards used in multiple industries and even multiple types of cleanrooms, and when there is overlap in those standards. Here we’ll focus specifically on ISO classes: what they are and why they matter.

What are the ISO classes?

The ISO classification system has eight classes, ISO Class 8 being the least controlled and ISO Class 1 being the most controlled.

Maximum Number of Particles in Air by Particle Size

ISO Class≥ 0.1μm≥ 0.2μm≥ 0.3μm≥ 0.5μm≥ 1μm≥ 5μm
ISO 11020000
ISO 21002410400
ISO 310002371023580
ISO 41000023701020352830
ISO 51000002370010200352083229
ISO 61000000237000102000352008320293
ISO 7352000832002930
ISO 8352000083200029300


Why does ISO classification matter?

Most laboratory and cleanroom applications require a controlled environment. The level of control depends on both the industry and the specific application. Cleanroom classes serve as a standard that can be easily referenced for the required level of environmental control. Additionally, they serve as a standard for certification to ensure that a cleanroom meets the proper level of control for the industry and the specific tasks performed in that cleanroom.

To create a cleanroom that meets your required ISO standard, contact Angstrom Technology. For more on cleanroom classifications and standards, including Federal Standard 209E, check out our guide.