NEVER!! It can be recycled, it can be broken down to microscopic pieces, but it doesn't go away.
Did you know that there is an Island of Trash (Mostly plastic) in the Pacific Ocean the size of the State of Texas?
It's called "The Island of Plastic", or the "Trash Vortex" or "The Pacific Gyre"... or "Great Pacific Garbage Patch", those are the few names that I have heard it called. I once had to do a very in depth research project on this huge floating trash Island... Ignorance is not bliss and it's important that people know what they are doing to their planet and what they are leaving behind for their children.
There are SO many ways we can recycle, reduce and reuse... it doesn't take that much time, and really... How hard is it to rinse your coke bottle and put it in the recycle bin? It's scary... these plastics are breaking down in our oceans, the fish are eating these teeny plastic pieces and especially the chemicals they leave behind, and then we EAT the fish... the chemicals that plastics leave behind can cause all sorts of problems and have even been known to increase the risk of miscarriage.
On that note, I found a Happy thing you can do with plastic... I don't know if Folgers is World Wide, but here in the States we can buy coffee in huge plastic red tubs, instead of recycling, we can reuse them! Folgers has made it so that you can go to their website right Here... And you can download labels to put OVER your coffee labels and re-use the containers!! They are perfect for Cookies!! YAY!! Go Team Folgers!!!
Here are the super cute prints, they are cute right??.... Ohh... I almost forgot, or you can make your own!! Plastic problem solved? Well... I'd like to think I'm doing my part :)