Particle precision
Graham Lewis, Corporate Key Accounts Manager – Colorex, from Forbo Flooring Systems, takes a look at the flooring considerations required for a cleanroom environment
The requirement profiles of floorcovering products for technical and cleanroom application areas are becoming increasingly complex, constantly presenting architects, engineers and end users with new challenges.
The concentration of airborne particles in a cleanroom is restricted to specified limits defined by the number of particles per cubic metre at a precise particle size. The ambient air outside in a typical urban environment contains 35,000,000 particles per cubic metre in the size range 0.5μm and larger in diameter, corresponding to an ISO 9 cleanroom, while an ISO 1 cleanroom allows no particles in that size range and only 12 particles per cubic metre of 0.3μm and smaller.
The only way to control contamination is to control the total environment by eliminating sub-micron airborne contamination generated by people, processes, facilities and equipment and removing them continuously from the air.
It is imperative that anything entering a cleanroom, starting with the construction materials, is declared safe and appropriate for cleanroom use. Guidance can be taken from standard regulatory requirements, which include the Assessment of the Microbial Behaviour on Surface according to ISO 846, Chemical Resistance according to ISO 2812-1 and Surface Cleanability Rating according to the German VDI guideline 2083, Part 9.1, with the two key ISO standards of Particle Emission by Dynamic Friction and Classification according to ISO 14644-1, Outgassing Behaviour and Classification according to ISO 14644-8.
The suitability of a floorcovering, therefore, largely depends upon the product properties and performance once in situ. Careful consideration must be given to the product’s functioning, resistance to strong chemicals and any micro-organisms, its effect on exposed products and whether the floorcovering can be kept free from bacteria and moulds by standard cleaning procedures. The ISO standards for air cleanliness in cleanrooms as well as the cGMP regulations impose strict contamination controls on materials to the pharmaceutical and life science industries, whereby they must present persistent results and compliance must be validated on a regular basis by trusted authorities.
For more information on Forbo Flooring Systems please visit www.forbo-flooring.co.uk/colorex