My employer has a lot of scrap greenboard, wolmanized plywood, pressure-treated plywood, whatever you want to call it. I am retrofitting a vent fan into my bathroom and make some kind of bracing between the ceiling boards and would like to take advantage of this free wood. Also I would like to use some of it to make a path to stand on also.

Are there any regulations regarding the use of this wood inside a home? I don't know if it's more flammable or something and can't really find any info. Plus it's got to be inspected and I want it to be right.