Cleanroom classes

Cleanrooms are divided into cleanroom classes (or purity classes) depending on the particle density. They are subject to strict, standardised requirements for the maximum permissible particle concentration (particles per m3) and are classified according to the degree of purity of the air. The limit values are specified in the relevant standards and guidelines DIN EN ISO 14644-1 and EC-GMP Guide, Annex 1.

To determine the cleanroom class, particle measurements are taken after the construction of a cleanroom. Even during operation, the systems must be checked on regular basis. We carry out qualifications or requalifications and provide proof that your cleanroom meets the relevant limit values.

Cleanroom classes according to DIN EN ISO 14644-1

Classification of purity classes according to DIN EN ISO 14644-1:2015

Purity Classes ISO-14644-1
The ISO standard is frequently used in the medical technology, optical and laser technology, micro-electronics and micro-mechanics, automotive and other industrial sectors.

The standard DIN EN ISO 14644-1 divides cleanrooms into classes ISO 1 to 9. Purity class 1 is the purest, i.e. the maximum permitted particle concentration is the lowest. Class 9, on the other hand, achieves the lowest purity. For most applications in the ISO range, cleanroom classes 7 and 8 are sufficient. ISO Class 5 complies with purity class A according to the EC-GMP guideline and meets particularly high purity requirements.


Cleanroom classification according to the EC GMP Guide, Annex 1

Purity Classes GMP-Guideline
The EC GMP Guide, Annex 1, is mainly used in sectors where "Good Manufacturing Practice (GMP)" is of central importance. These include, among others, pharmacy, biotechnology, medical technology or the food and cosmetics industries.

The EC-GMP Guide, Annex 1 defines the cleanroom classes A, B, C and D. The class A has the highest/purest level, the cleanroom class D allows the largest maximum permissible particle concentration. Up to class A, no purity classes may be skipped. Class D must pass through class C and B to operate in cleanroom class A.

Der EG-GMP-Leitfaden, Annex 1 definiert die Reinraumklassen A, B, C und D. Die Klasse A weist dabei die höchste / reinste Stufe auf, die Reinraumklasse D erlaubt die größte maximal zulässige Partikelkonzentration. Bis zur Klasse A dürfen keine Reinheitsklassen übersprungen werden. Es muss von Klasse D die Klasse C und B durchlaufen werden, um die Reinraumklasse A zu betreiben.


VDI 2083

Eine weitere nennenswerte Norm ist die VDI-Richtlinie 2083. Sie ergänzt die DIN EN ISO 14644-1 um praktische und branchenspezifische Aspekte und stellt auch spezifische Anforderugnen an die Reinheit des Raumes, der Prozessmedien, Mitarbeiter und den Arbeitsplatz.
Praktische Aspekte sind dabei bspw. Regelungen für die Energieeffizienz, während branchenspezifische Aspekte auf die Besonderheiten der unterschiedlichen Branchen (bspw. Medizintechnik, Pharmazie, Mikroelektronik etc.) eingehen.

You would like to have your cleanroom classified or have questions about the cleanroom classes?

Please contact us


Read more about cleanroom qualifications