Appropriate masks disappeared quickly after the California wildfires. According to an article in the LA Times, the type of mask to get is an N95 respirators or P100 masks. A surgical mask or a hardware store dust mask will NOT protect your lungs from wildfire smoke particulates.
The FDA says: "The ‘N95’ designation means that when subjected to careful testing, the respirator blocks at least 95 percent of very small (0.3 micron) test particles. If properly fitted, the filtration capabilities of N95 respirators exceed those of face masks. However, even a properly fitted N95 respirator does not completely eliminate the risk of illness or death.
"N95 respirators are not designed for children or people with facial hair. Because a proper fit cannot be achieved on children and people with facial hair, the N95 respirator may not provide full protection."
Adult masks don't fit well on children's faces either, so I'm adding some Ligart kid-sized masks to my supplies for the grandkids and neighborhood kids. Better safe than sorry, and ahead of the demand.