Don’t buy this · Air
Don't buy an ioniser or an ozone generator
The verdict
Ionisers charge airborne particles so they stick to walls, floors and furniture. Airborne measurements improve; the particles are still in your home and are resuspended when anyone moves. Ozone generators are worse — ozone is a regulated ambient pollutant with an India NAAQS limit of 100 µg/m³ over eight hours, the concentration needed to sanitise is far above what is acceptable to breathe, and ozone reacting with ordinary household cleaning products produces formaldehyde and ultrafine particles in the room.
When this does not apply to you
Placed here rather than at the end, because if one of these describes your situation then the rest of this page is the wrong advice and you should know that now.
Professional ozone shock treatment of an unoccupied space
Genuine remediation practice for severe odour in a vacated property, done by people with the equipment to do it and followed by thorough ventilation before re-entry. That is a completely different thing from a device running in your bedroom.
A purifier whose ioniser can be switched off
Many good HEPA units include an ioniser mode. That is not a reason to avoid the unit — just leave the mode off. You lose nothing, because the HEPA is doing the work.
Industrial and commercial applications with engineering controls
Ozone has legitimate industrial uses under controlled conditions with monitoring and exclusion. Nothing about that transfers to a household appliance.
Why you were told otherwise
Usually not because anyone lied to you. Almost every claim in this category is technically true and incomplete, which is a much more durable technique.
- Ionisers are cheap to build — no filter media, no replacement consumable, which is also why they are marketed as 'filterless' and 'no running cost'.
- A particle monitor genuinely does read lower with an ioniser running, which makes the demonstration convincing.
- 'Filterless' is an attractive claim in a category where consumables are the real cost.
- Ozone is renamed — activated oxygen, energised oxygen, trioxygen — specifically because ozone has a poor regulatory reputation.
What to do instead
A page that only says no is an opinion. This is the part that makes it useful.
- 1
Buy an H13 HEPA unit sized for your room
Mechanical filtration actually removes particles from the air rather than relocating them, and it does not generate anything.
Read more → - 2
Add real activated carbon if odour is the concern
Gases need carbon, and how much carbon decides whether it works. Ask for the mass in grams — a serious gas filter carries hundreds of grams to kilograms.
Read more → - 3
Check for CARB certification before buying anything with an ioniser or plasma mode
If the manufacturer will not publish an ozone emission figure, treat that silence as an answer.
Read more →
Note
Frequently asked questions
Do ionisers actually clean the air?
Are ozone air purifiers banned in India?
My purifier has an ioniser mode. Should I use it?
Cost figures are indicative Indian market ranges for budgeting, last reviewed 2026-08-08. This page argues about the general case; the exceptions section above is where the specific case is dealt with, and it is written honestly rather than as a hedge.