After announcing proposals to manufacture LEGO® bricks from recycled PET in 2021, the toy giant has shelved the plans after finding using the material did not reduce carbon emissions. The move, which was first reported in The Financial Times, comes after the Danish company unveiled a prototype LEGO® brick made from recycled plastic in 2021. The prototype used PET plastic from discarded bottles and Lego said was the first brick made from a recycled material to meet its quality and safety requirements.However, after more than two years of testing, it found using the material didn’t reduce carbon emissions because of the extra steps required in the production process that use more energy.

The recycled bricks were made with plastic from U.S. suppliers approved by the Food and Drug Administration as well as the European Food Safety Authority. Through Lego’s manufacturing process, a single one-liter bottle could produce ten 2×4 Lego bricks. The company tested around 250 variations of PET materials before settling on the final brick formulation.

Lego’s foray into sustainable bricks did not begin in 2021, however. In 2018, the toy company announced that it had begun a production line using sugarcane. While sugarcane is a more sustainable option than plastic, which is created as a byproduct of sucking oil out of the ground, the new bioplastic was softer and more flexible than its counterpart. As a result, Lego has only been using sugarcane plastic in its line of plant-shaped bricks.

While recycling bottles into Lego bricks might have been a bust, the company is reportedly still interested in transitioning to other sustainable solutions. The company was looking to make its bricks from sustainable materials by 2032—whatever that means.