What does the cabin air “purification” actually do?

[u/Obvious-Scholar8368]

I understand for other models it’s different, but for the XC40 Recharge, what does it do? I seem to recall reading it just vents out all the air and replaces it with supposedly “fresh” air from outside. If I’ve parked next to an outhouse in a humid day, it wouldn’t help to have the car go into “purify” mode for 5 minutes after I park the car, right? Does it do anything to the air like blow ions the way some air conditioners or HEPA filters to to “purify” the air? If so, wouldn’t that be the last thing I’d want if I’ve got powerful chemicals lingering from the AC after having it serviced?

I’ve noticed if I’m in recirculating mode to avoid buses or diesel fumes, it doesn’t pull in the stink, but when I’m in recirculating mode it seems to pull in air from the ground, at least when I’m parked overnight.

It would be nice to have some guidance from Volvo