ULPA filters

                           ULPA  filter stands for Ultra Low Particulate Air. Growing market demand from advanced science and technology led to development of  ULPA filters which provide a

                 minimum of 99.999% efficiency (0.001% maximum penetration) on 0.3 micron particles for achieving better cleanliness classes and cleaner working environments. 

                These are used for ultracleanrooms, where contamination levels have to be controlled at levels better than that which can be achieved with conventional HEPA filters.

               Boron free ULPA filters of 99.9997% efficiency for particles down to 0.12 micron size for Class 10 and Class1 cleanrooms are specially used in electronic/semiconductors/ wafer manufacturing industries, 

              where tolerance to contamination level above 0.12 micron is also very critical and not permitted.

             Note that the text information for instance on the efficiency @ 99.97% and 99.997% of HEPA filters look similar but in reality the difference is not insignificant. 

             A 99.97% efficient filter has a fractional penetration of 0.0003; while a 99.99% filter’s fractional penetration is 0.0001. This means that a 99.99% filter is three times more efficient in removing 0.3-micron particles.