Keeping a few N95 masks, as well as "more powerful silicon mask" is a good option. If you are confronted with a dust situation, rather than a chemical situation, you can elect which device to use. In a small office, you could easily have enough N95 masks for everyone without incurring large cost ?

Although Iím in a large office, I have enough N95 masks for my immediate colleagues/work friends (half a box). Iím not sure if thatís a guilt thing or good prep ? (but Iím not specifically preping for more than myself)