text: Most people who know anything about science think so.  When you say "eco-friendly" I assume that you mean "non-poisonous".  The chief complaint would be that the stuff just does not break down.  It takes aeons to break down.  However, it is inert to your body and anything else alive.  It is a super-long hydrocarbon which has no reactive functional groups whatsoever and hence can't really do anything other than burn.  By the way - it's spelled polypropylene.