Below is a list of Class 100 Clean Rooms manufacturers from Clifton Park, New York. Class 100 clean rooms are the third highest classification in Federal Standard 209 standards. In order to meet regulations, a Class 100 standard clean room must never exceed 100 particles per cubic foot (the particles being 0.5 microns or larger). As a reference point for just how small 0.5 microns is, the average human hair is approximately 75-100 microns in width.