Half life of N2?

Hi,
I use an ozone generator to control the population of mold spores in a clean
environment. I constructed it myself, basically it's a pyrex tube wrapped in
conducting foil with a conducting wire mesh rolled inside. A very high
alternating voltage is imposed across the foil and mesh, and air is forced
through the tube, dispersing large amounts of ozone into the room.

I have been told that high voltage ozone generators run in plain air
environments also generate unstable N2 molecules, a known carcinogen. Can
anyone comment as to the truth of this statement? If true, then what is the
half-life of N2?

Chemistry is not my strongest skill, I just want to make sure the
sanitization procedure is safe. No-one is present in the room while it is
being ozonated, and I need to know the minimum time before the room becomes
safe to inhabit again (I believe the half-life of ozone is roughly 1/2 hour,
I have been allowing a minimum of 2 hours for decay.).

Thanks,

Adam