With respect, a couple of comments regarding wildfires, which in the Los Angeles current condition, includes combustion contaminants from all sorts of "non-forest" materials, as you mentioned:
The particulate-filtering (important concept) facepieces you mention (N95, P100), are just that--they filter out suspended particles in breathed ai…
With respect, a couple of comments regarding wildfires, which in the Los Angeles current condition, includes combustion contaminants from all sorts of "non-forest" materials, as you mentioned:
The particulate-filtering (important concept) facepieces you mention (N95, P100), are just that--they filter out suspended particles in breathed air. N95 (not resistant to oil) and P100 (resistant to oil) remove 95% and 99.97%, respectively, of those particles of a size diameter greater than 0.3 micrometers. Neither are considered effective for air that contains VOCs (volatile organic compounds), and other types of gaseous contaminants. (Caveat: VOCs and acid gases that have adsorbed onto, or absorbed into, particles could be effectively captured by the facepiece material, but I do not know if this has even been researched.) Users are misled if they think that a N95 or P100 filtering facepiece provides 100% protection. (Hence, your comment "... P100 if you’re clearing burn sites or fighting fires, as these catch even the smallest particles" is misleading; reportedly just woodland fire smoke particles (fine particles, PM-2.5) alone are believed to be in the 2.5 to sub-2.5 micrometer range.) Proper fit is important, for materials that can remain airborne follow the path of least resistance; examples are improper size/fit, improper donning/wearing, failure to obtain sufficient face-to-facepiece seal (main culprit--facial hair).
Finally, with all that being said ,just about anything used to filter the air is better than nothing, as long as it is understood that there are limitations to all choices available, and some choices may have fatal outcomes (e.g. high levels of carbon monoxide). If all you have is a wet bandana--use it.
With respect, a couple of comments regarding wildfires, which in the Los Angeles current condition, includes combustion contaminants from all sorts of "non-forest" materials, as you mentioned:
The particulate-filtering (important concept) facepieces you mention (N95, P100), are just that--they filter out suspended particles in breathed air. N95 (not resistant to oil) and P100 (resistant to oil) remove 95% and 99.97%, respectively, of those particles of a size diameter greater than 0.3 micrometers. Neither are considered effective for air that contains VOCs (volatile organic compounds), and other types of gaseous contaminants. (Caveat: VOCs and acid gases that have adsorbed onto, or absorbed into, particles could be effectively captured by the facepiece material, but I do not know if this has even been researched.) Users are misled if they think that a N95 or P100 filtering facepiece provides 100% protection. (Hence, your comment "... P100 if you’re clearing burn sites or fighting fires, as these catch even the smallest particles" is misleading; reportedly just woodland fire smoke particles (fine particles, PM-2.5) alone are believed to be in the 2.5 to sub-2.5 micrometer range.) Proper fit is important, for materials that can remain airborne follow the path of least resistance; examples are improper size/fit, improper donning/wearing, failure to obtain sufficient face-to-facepiece seal (main culprit--facial hair).
Finally, with all that being said ,just about anything used to filter the air is better than nothing, as long as it is understood that there are limitations to all choices available, and some choices may have fatal outcomes (e.g. high levels of carbon monoxide). If all you have is a wet bandana--use it.
See CU Boulder study for an idea of the dilemmas those who return to surviving homes face. Just entered link after your question.