. . . The envelopes have never smoked & have no pets. I also have no pets but there is one mouse who doesn't appear to eat anything, just dashes across the floor about once a week. I think he gets his sustenance downstairs. I have never seen him smoke. Maybe he thinks I'm his pet.
. . . Alas, however, if I didn't smoke, I might not bother to breathe at all.
. . . Simple answer - not smoke free.
. . . The envelopes are available smoke free from Staples in boxes of 250. They call 'em "no.1 coin envelopes".