Hi Stephen
We had a similar question about this some time ago.
Besides our Winix air purifiers having high quality HEPA and Carbon filters, they also use PlasmaWave technology which is quite differant to traditional ionisers found on the market.
Below is a more detailed explaination that we posted a little while ago about this technology.
I hope this helps, however if you require further information please don’t hesitate to contact Ausclimate on 1800 122100
Regards
Allan
Ausclimate

“This technology has been tested and certified by various Australian and international testing agencies/universities to effectively and safely remove harmful airborne pollutants such as bacteria and viruses. Unfortunately, it can sometimes be confused with ‘ionizer technology’ (or ‘negative ion air purifiers’) that can produce high levels of ozone. Negative ion air purifiers do not actually eliminate air pollutants. Instead, negative ions force contaminant particles to group together so they are weighed down onto the surface of furniture and floors. Everyday activities such as walking or vacuuming can then reintroduce these contaminants by making them airborne once again. PlasmaWave is far superior whereby it produces both negative and positive ions at the same time, unlike ionizers that only produce negative ions. These ions from Plasmawave technology latch onto pollutant particles and alter the chemical structure. As a result, they’re able to safely eliminate the pollutant particles.

Ozone emission safety is very important to us. In fact, we have confirmed that the ozone levels produced by Plasmawave technology are so low that it is virtually immeasurable. In tests carried out by an independent laboratory, PlasmaWave produced only 3 ppb (parts per billion) – which is substantially lower than the allowable level of 50 ppb as set by the USA’s FDA. All Winix products are certified by the California Air Resource Board to ensure Ozone emissions are well below the air cleaner limit of 50 ppb ozone emission limit. Winix’ Plasmawave® Technology also meets the California Air Resource Board’s AB 2276 standard, which is the most rigorous American certification benchmark for indoor air cleaning ozone-emissions. To attain compliance, air cleaning devices must be tested for electrical safety and have ozone emission ratings below the 0.05 parts per million limit.

And further to this, the PlasmaWave function can still be turned off if you choose.”