Why does my head stay outside the ozone sauna?

The whole design logic follows from one fact: ozone must never be breathed in. That is why we build the cabinet to enclose everything below the neck and nothing above it — the design behind transdermal delivery, giving a substance across the skin rather than by mouth, injection or breathing. Ozone can be harmful to the respiratory system and eyes in large quantities, and that is the reason your head is outside the ozone sauna and you cover the neck.

So what are you actually breathing? Ordinary room air, for the whole session, exactly as you would sitting in a chair in the same room. Nothing is piped to your face and there is no mask or mouthpiece.

Practical points for a session:

• Sit so the neck seal or towel closes the gap. Steam escaping in a thin plume is normal; a sudden large amount usually means the bottom door rubbers have been knocked out of place. Anything letting steam out is letting ozone out too — off-gassing.
• Do not lean in, put your face into the sauna, or open the doors to look inside while ozone is running.
• We warn specifically against wooden saunas used with ozone: most do not allow the head to stick out, so the user inhales ozone for the entire session.
• Ventilate the room, and do not rely on your own nose to detect ozone. Operators become desensitised to the smell.

To get out, open the doors and step out. To stop the ozone, switch the sauna off at its wall socket once you’re out. If you smell ozone or feel unwell, follow the steps on feeling unwell.