Full face shield
Ok, I think the best way to answer your question is this; are you really serious about the protection? If the answer is yes, then find out which system is best for you, using what ever means you can Internet, friends and colleges. I did a bunch of research for myself and decided on the 3M Powered Air Purifying Respirator (PAPR). I was motivated by the fact my wonderful wife brought me back a piece of wood from a mission trip to South America and I had a really bad reaction. I mean I spent 45 min. outside trying to catch my breath and waiting for the welts to go down. I then spent 3 month watching e%@& for a good deal. I spent about $300 total on a $1300 powered air flow system with OV/HEPA cartridges. If you know what you need you can buy the parts to put it together. The chunk of wood is still sitting over in the corner where it was thrown, smiling at me. I remember to wear the mask even during the summer. Your health is important; I'm not sure what it's worth, but for me $300. Domestic woods don't bother me, at least what I can see, but that doesn't mean they aren't damaging your lungs with the fine dust. I know people that have smoked for 40 years and are still kicking; I'm just not willing to take the chance.