Paint fumes? What about them? Think about it...
Most likely, if the paint fumes are a high enough concentration to flash, the human painter will have passed out from the fumes. That's assuming the painter isn't wearing a respirator and using proper ventilation. Then again, if someone has the money to afford proper ventilation equipment, they will make sure they have a safe heat, regardless of cost. They'd do everything right.
I know autobody shops with high concentrations of paint fumes - with an open flame propane heater on the wall. If it's really chilly, they fire up a torpedo heater. They have really big exhaust fans venting the paint fumes out of the paint booth too. If you do things right, and use a little common sense, it's safe to use an open flame around paint fumes.
You can extinguish a match in a can of gasoline too...
Wood dust is explosive? So what... Think about it...
If the wood dust is a high enough concentration to flash, visibility will be so low that the human woodworker will be busy trying to keep from chopping their hands off in a power saw.
That is, if the human woodworker hasn't passed out from oxygen deprivation from breathing so much wood dust.
A shop vac or dust collection system can easily keep wood dust concentrations low enough that you won't have to worry about wood dust explosions.