The biggest problem with them is that the dev seems to completely misunderstand how they work.* Residential central A/C in the SE US (where we're set) doesn't draw in air from outside; it recirculates the air in the house. The more you run the unit, the more you blow the fog/mist/whatever over the condenser coil (outside), and therefore the more you shorten the lifespan of the system, but it isn't going to bring the fog inside.
I'm pretty sure this is true of commercial systems as well (e.g., in the office buildings), but I'm not as familiar with them.
toxic air seems to have magical properties
Yes, it does.
is there some real world equivalent that does the same as in the game
Not really. The closest I've come up with (or that I've seen discussed in this thread) would be something corrosive. That would account for skin, eye, and lung irritation. It would account for being able to wash it off with water. It would account, perhaps, for disabling or degrading wireless communications (because it could damage antennae, cables, or connections). It could account for disabling vehicles.
But then there's a lot that's unexplained. If it's corrosive enough to disable a vehicle in a matter of minutes (as I've seen it do once, and apparently happens again in the latest update), Laura should be dead--she was out in this shit, unprotected, for hours before she returned to the office building at the start of the game. If it's corrosive, why are exposed metals not damaged? Why are landline communications affected? Why is power still on? How does this stuff, apparently (we haven't actually seen this happen, but it's the working understanding of our cast), turn people into Burned Ones/Witches? I could go on, but I think that's enough.
So, if I can't explain it IRL, I'm going to call it supernatural. Maybe it's aliens, maybe it's something to do with the hidden burial ground we saw teased at MC's home very early on, maybe something else, but that's where I've landed for the time being.
* Yes, yes. It's just a game, I should really just relax.