Very interesting topic !
I also used one. Very modern toy =]
My can print two types of plastic.
One is ABS fillament, which is one of most comen plastic.
And another is PLA - plant based fillament, mainly made from corn !
ABS can be recycled to new ABS fillament.
And PLA can just be left on the sun, and in some time it going to fall into peaces with out any harm for the nature.
Whery interesting technology !
=]
That's good to know. Recycling has to be a consideration.