For folks who use plastic cat pan liners and would rather not be throwing away so much plastic, BioBag now makes biodegradable ones. They haven't hit the local stores yet, but I order BioBag trash bags from drugstore.com. (I don't use cat pan liners, but I use their doggie cleanup bags when I scoop out Smudge's box.) The garbage bags are certainly plenty tough for household use.
Love, Columbine
