Plasmacluster Ion technology is a patented technology of SHARP Japan whereby it produces positive and negative ions (Bi-Polar Ionization) which has been tested to be completely safe. However, the benefits of Plasmacluster are not completely clear to us. One is able to turn the Plasmacluster Ionisation off on the SHARP machines. We however, still believe the SHARP machines are worth their price even without the ionization. The fan and filters are good enough to remove PM2.5 and certain odors.