Is media blasted residue harmful? Options

[914itis]

My car was soda media blasted I think ( its the white stuff that looks like baking soda) before I got it and went on with the restore. There was powder everywhere. I cleaned all the visible residues before restoration and paint.

For the first time, I completed the installation of the heating system last month. As I had the heat on with the fan blowing, I noticed the soda smell coming out of the vents.

Can the smell do any harm?
What is the best way to clean the heat tunnel?

I don't think there is much in there, I uses a vac to blow and suck the dust before installation. Can I just detach the hose coming from the firewall / long to the flappers. Them disconnect the hose behind the speakers and water hose it ? What would you suggest?
All opinions welcome.

[Madswede]

Hmm. "Media" is just a generic catch-all term that includes soda (sodium bicarbonate) as well as silica (sand), glass beads, water, dry ice, even crushed up nut shells, you name it.

I don't know why somehow the term has been applied by some paint blasting guys to mean something specific, but "media" is truly a generic term. I'd ask them what media they used, exactly. I'm betting it was soda or glass beads.