EN ISO 14644: Standard for determining the cleanroom classification
EN ISO 14644 (in Germany DIN EN ISO 14644) is an internationally valid standard for cleanrooms and cleanroom areas. With the help of the standard, it is possible to divide rooms into cleanroom classes (ISO 1-9). The standard also takes into account aspects relating to the planning, operation and control of cleanroom facilities.
Originally developed in the semiconductor industry, EN ISO 14644 replaced the old US FED STD 209E standard in 2001. And in the meantime it has established itself in numerous industries – including aerospace, optics, pharmaceuticals, food, medical technology and healthcare.
In order to divide cleanrooms into cleanroom classes, EN ISO 14644 focuses on the concentration of particles in the air. The standard sets limits for the maximum permissible particle concentration per cubic metre of air. And assigns the degree of purity to cleanroom classes ISO 1-9. This is how ISO class 1 cleanrooms achieve the highest level of purity. For this purpose, a maximum of ten particles with a maximum size of 0.1 micrometres may be present in a cubic metre of air.
In order to determine the concentration uniformly, the standard specifies not only particle limit values but also recognised test methods. Modern particle measuring instruments are often equipped with a laser diode for the most accurate measurement. A table shows the minimum number of measuring points per area. The room meets the requirements if the average value of each measuring point does not exceed the limit values.