How to (safely) produce flying dust on set? Simple question, mainly asking for your collective experience.

I am planning a short-film in a post-apocalyptic scenario which is supposed to be very dusty with a thick-looking atmosphere. Part of it is easy to achieve with haze or fog, but I was wondering about those little specks, kind of like ash blowing in the wind.

How would one safely achieve something like this? Is it a good idea to actually just blow around some burnt paper (essentially ashes)?
I would avoid burning things to make ashes. Not very environment-friendly.
Instead of paying attention to the acting and to the light, and framing you will be worried about the effects. That is not a good idea.
Now days is pretty simple making particles in a 3D program. Try Blender, that can track the footage and have a very robust particle system and render options.
Here is an example of how a normal scene can be transformed into an apocalyptic scene, one typical example is Silent Hill.