Is polyurethane earth-friendly?
Figaro Subrosa: Perhaps “friendly” is too strong a word, but the earth did accept polyurethane’s “friend request” on Facebook. Joking aside, once it is dry, polyurethane is inert and therefore landfill safe. However, in its liquid form, it may contain both solvents that should not get into the water table and solvents that can be ozone generators. Looked at it that way, the answer would have to be no, but to put it in perspective, most hobby woodworkers do more damage to the environment driving their car for one month than they do with all the finishing materials they use in a lifetime.