Respirator?

[Ross]

While this is true, if you're in that extreme a condition, pressurized breathing equipment is probably a better idea.

For normal use, the full-face respirator with replaceable cartridge filters are far more economical than disposable masks, especially if you need the P100 level of protection, since the only disposable masks I've seen topped out at P95.

Those extremes were rare and we cleared out of the way for those. The masks we used were N95 and a pressure system would have been very inconvenient in a 35 room 4 floor house that had been divided into 8 apartments. There was plenty of cross ventilation because almost of of the windows were broken. Neighborhood dust control was not a problem because we were a 1/4 mile from the highway and a mile from the nearest house.