One area that is often overlooked in the cleanroom is the use of specialized office equipment.  This can range from office chairs to pens and papers.  These supplies are manufactured to obstruct particles from generating and some products are impregnated and coated with polymer.   Furthermore many of these products are typically manufactured and packaged in a clean room environment to ensure their sterility when you receive them.   Like most things used in a cleanroom, be sure to do some research and find the right materials for your clean room.