Source: http://www.motherjones.com/blue-marble/2...

Green Mountain only makes 5 percent of its current cups out of recyclable plastic. The rest of them are made up of a #7 composite plastic, which is nonrecyclable in most places. And for the small few that are recyclable, the aluminum lid must be separated from the cup, which also must be emptied of its wet grounds, for the materials to make it through the recycling process. Even then, chances are the pod won't be recycled because it's too small, says Darby Hoover, senior resource specialist at the National Resources Defense Council.

Keurig just released a sustainability report announcing that the company plans to make all coffee pods recyclable by 2020, among other ecofriendly efforts. The company says it's evaluating the type of plastic used in the cups, exploring potential biodegradable and compostable packaging, and coming up with an easier way for customers to easily prepare them for recycling.

Some competitors already have recyclable or biodegradable versions of this single-serve pod; Nespresso's lid and pod is made entirely from aluminum. A Canadian brand, Canterbury Coffee, makes a version that it says is 92 percent biodegradable (everything save for the nylon filter can break down). Finding a substitute is an interesting challenge, says Keurig spokeswoman Sandy Yusen, because coffee is perishable, and so the material used must prevent light, oxygen, and moisture from degrading the coffee.

Another reason to look beyond plastic is a concern with what could leach out of the material when heated. Yusen confirmed that the #7 plastic used in K-Cups is BPA-free, safe, and "meets or exceeds applicable FDA standards." But new evidence suggests that even non-BPA plastics can test positive for estrogenic activity. (Our "Frightening Field Guide to Common Plastics" contains more information about this.)

"No. 7 plastic means 'other,'" says the NRDC's Hoover. "You don't know what it is." One concern with this plastic mix is the presence of polystyrene, containing the chemical styrene, which Hoover warns is especially worrisome for workers. A possible carcinogen, styrene can wreak havoc on the nervous systems of those handling it, according to the Centers for Disease Control and Prevention. The chemical also shows up in tobacco smoke and home copy machines, and in the Styrofoam used in food containers.