I have a small ziplock bag in each FAK with N-95 masks and nitrile gloves; common N95 masks are readily available. I also have an Antimicrobial, Asthma/Allergy Air Filtering Dust Mask in the truck console, reusable and able to hold up better than a typical N95 mask.

But those masks really only cover dust particles & allergens, not the unburned fumes that are also released into the air. Have you ever blown out a candle and then brought the match into the smoke column to relight the candle without touching it? Unburned gasses rising in the smoke column... Which is why I’m looking to upgrade my real respirators to cover vapors as well as dust, smoke particles/soot.