I called Agway today to inquire about promix HP. I was told that they do not carry this because mycorrhizae can cause lung problems. I tried searching internet but did not find anything. Did anyone hear any association between mycorrhizae and lung problems?
What is the best potting mixture to use for figs?
Thanks,
Imran

Never heard that before. I have heard perlite dust isn't good to breathe in.

I use Promix and pine bark fines(pine bark mulch from Agway)

I have been using it for 3 to 4 years even inside during long winters. I don't suspect any issue with it.
The local garden centre runs out of it faster enough.

If you are concerned you could always wear a simple dust/particle mask when you are handling soil that is dry and dusty. IMO that is the only time it could/would possibly be of concern. Not saying that I have heard or know of anything about lung issues from mycorrhizae, just that breathing dust with spores would probably be a good vector if it were a true concern.

The fungus itself  shouldn't cause lung issues. There is a small chance someone could be allergic to the spores but it is like that with any fungus. I would be more worried about the other stuff in the mix. I use promix hp and use to grow mushrooms. I would recommend a mask for the other stuff in the mix.

Thanks a lot friends,
Imran

Promix HP is an excellent product, especially for newly rooted cuttings. often a seller will bad mouth a product that they don't sell in order to interest you in one they do sell. I have no knowledge regarding lung problems associated with Promix HP, but have heard, as stated by Jason, that perlite dust can be a problem.  

Try prying that ProMix away from me. Never!

(Cough cough)