Hey people, rj Brooks. Sharing my experience. The material i have worked with for years has been the source of the chemical exposure. PT lumber, plywood, OSB or flake board, particle board, Masonite. I have reached the point where I cannot allow any exposure to the dust created from working with these materials. I just invested in new charcoal filters so I don't have to stop what I do for a living but at the same time I wish manufactures of so many of the building trade materials could stop with the saturated nasty stuff. You will have to consult your MSDS on the material you personally work with to identify nasty stuff but its there. I took it for granted coming up through the the trades. Now I'm paying for it.