Members,
With an advanced degree in biology, I can finally prove I have some expertise in one of our discussion topics. I have also never employed a dust extractor in my home studio. I have always worn a dust mask because of this.

Viri (plural of virus) were brought up in the discussion. I am not addressing these in this post, except briefly. They are much smaller than anything a woodworker will encounter and one member explained very clearly that the reason N95 masks work with the current virus is because they stick to larger droplets and other particles which are then caught by the N95 mask.

The dust created by woodworkers is much larger. In general, most of it is harmless under occasional exposure. However, some woods can trigger an allergic or inflammatory response. Each person reacts differently to certain types of wood. There are about 100 species, mostly tropical, which cause an allergic or inflammatory response in most people. Some people are sensitive to woods which do not cause problems in others. Many people, including myself, get irritated by Cedar dust (Juniperus). I guarantee you that if I dry then grind up the bark of a cinnamon tree, you’ll find it tasty on certain foods but you will find it irritating if you breathe it in. This is an example of an inflammatory response. In general, a dust mask is necessary for people who are sensitive or for people who spend a lot of time working with wood dust. The N95 mask is ideal for this.

Fungus spores and pieces of ground up fungi can cause an inflammatory or allergic response in many people. This is why they recommend using an N95 mask whenever creating dust from spalted wood. Generally drying spalted or any other wood in a steam kiln will kill all fungi. Freezing, drying, and most home kilns will not. Even if spalted wood has been dried in a steam kiln, woodworkers are still recommended to always use an N95 mask when creating dust as some people might be sensitive.

Most mold spores do not stick to larger particles. For those who work in tight spaces with rotted or spalted wood that might be producing spores, I recommend a P100 mask. (Google search result for P100 respirator.)  Fresh wood has to be air dried with generous airflow. For those who are having trouble with fungus growth when they air dry their wood, there are a number of lumber dips which can be used to prevent the growth of fungi. Almost all commercial sawmills which air dry their wood employ lumber dips. Pre-drying, by rotating the boards in fresh sunshine for a week or 2 is sometimes sufficient.

Woodworkers often wear safety glasses along with the facemask. To avoid fogging your glasses, I recommend using a mask with an exhalation valve. For occasional exposure to liquid mists or irritating organic vapors, like you might find with spraying finishes, I would recommend an R95 mask. They usually do not come with a valve. I also recommend 3M products. I have used them for over 30 years. A single mask can be used repeatedly as long as the elastic straps maintain the seal to your face and as long as you store it with the face side down.

Stay healthy,
David Bisant, PhD