Ever since the company’s founder, Ole Kirk Christiansen, bought Denmark’s first plastic-injection molding machine in 1946, Lego pieces have been derived from oil, a fossil fuel.

It’s a thermoplastic with a low melting point that can be easily injected in the Lego company’s molding machines to produce bricks with extraordinary precision, durability, and hardness.

Originally called "Automatic Binding Bricks," the company's trademark toy was invented in 1949, after the company got its first plastic injection-molding machine. LEGO was founded in 1932 in ...