Lego debuted its first bricks made from recycled plastic bottles in an effort to build toys with more sustainable materials

• Lego debuted its first prototype brick made from recycled plastic bottles.
• This is the first Lego made from recycled materials to meet Lego's quality and safety standards.
• On average, the plastic of a one-liter PET bottle is enough to make 10 two-by-four Legos.

Lego has turned plastic bottles into its iconic bricks in a push to use more sustainable materials.

The Danish toy maker unveiled its first prototype brick to be made from recycled plastic on Wednesday. This is the first Lego made from recycled material to meet the company's quality, safety, and play standards.

The prototype is made using PET (polyethylene terephthalate) plastic from discarded bottles. On average, a one-liter PET plastic bottle supplies enough raw material to make 10 2-by-4 Legos.

Hundreds of plastic formulations have been tested for use in Lego bricks over the past three years, according to a company press release.

"We want our products to have a positive impact on the planet, not just with the play they inspire, but also with the materials we use," said Tim Brooks, Lego's vice president of environmental responsibility, in the release. "The biggest challenge on our sustainability journey is rethinking and innovating new materials that are as durable, strong and high quality as our existing bricks - and fit with LEGO elements made over the past 60 years."

Lego will keep experimenting with the use of PET plastic before determining whether to start piloting production of these bricks. The next stage of testing will likely take at least a year, the release says.

The recycled PET plastic that goes into the prototype comes from US suppliers that use processes approved by the Food and Drug Administration, as well as the European Food Safety Authority. Strengthening additives are combined with the plastic to increase its durability.

The company's broader push towards sustainability includes the 2018 launch of Lego elements made from plastic sourced from sugarcane. Last year, the company announced it will phase out single-use plastics from its boxes in an effort to make all of its packaging sustainable by 2025. The company also plans to invest up to $400 million in sustainability efforts over three years. Lego also hopes to send zero waste to landfills by 2025.

Lego defines a sustainable material as one that is "responsibly produced, using renewable or recycled resources, generating little or no waste, use sustainable chemistry and be fully recyclable at the end of its life."