JohnF writes:

I know there is something cheap and relatively safe (can't kill
anyone except management) I could use to figure out air flow in the
shop.

Wal-Mart sells fog juice and generators. At least around Halloween. Or a
party store or Spencer gifts.

Don't use ethylene glycol antifreeze; highly toxic! Non-toxic antifreeze
or glycerin.

Insect foggers (Home Depot, Lowes) make a mineral oil fog that is harmless
in low doses. Can also use fog juice in them.