> Most LEGO pieces are made of durable ABS plastic and will never decompose. Some pieces are made of other plastics, metals, silicon, and other elements. Sourc

> Most LEGO pieces are made of durable ABS plastic and will never decompose. Some pieces are made of other plastics, metals, silicon, and other elements. Source: http://www.brickrecycler.com/lego-fun-facts/ http://www.brickrecycler.com/lego-fun-facts/ Also of interest there was an article that found bricks keep their holding strength for ~37k attachments.