Frequency distribution of 67 random particle events encountered in a class 10–100 cleanroom environment while carrying out the J-FIL™ process. The exclusion zone radius was measured using a calibrated optical microscope. The x-axis represents the upper limit for the interval in which the exclusion zone was placed. For example, the x-axis value of 200 represents 12 exclusion zone radii measured between 100 and 200 μm.