Lego plans to make half of the plastic in its bricks from renewable or recycled materials instead of fossil fuels by 2026, as part of its latest efforts to make its toys more environmentally friendly.

The Danish company, which last year abandoned efforts to make bricks entirely from recycled bottles due to cost and production concerns, currently produces 22 percent of its colorful bricks using fossil fuels.

In the long term, Lego plans to switch entirely to renewable and recycled plastics by 2032. As part of this green initiative, the company has already tested over 600 alternative materials.

The toy maker hopes to gradually reduce the amount of petroleum-based plastic used by paying up to 70 percent more for certified renewable resin, the raw plastic used to make the building blocks, in order to encourage manufacturers to increase production.

Lego’s plastic producers are replacing fossil raw materials with alternatives such as cooking oil, waste fat from the food industry and recycled materials. However, as the market is still developing, the costs can be two to three times higher.

“This means a significant increase in the cost of producing a Lego brick,” Lego CEO Niels Christiansen told Reuters. “It is a privilege that we can pay more for the raw materials without having to charge customers extra.”

Last year, the group pledged to triple its sustainability spending to three billion Danish kroner (£340 million) a year by 2025, without passing on the higher costs to consumers.

Lego has also expanded its Replay brick take-back program – which allows consumers to donate old bricks to the company free of shipping costs – to the UK and continues to test similar models in the US and Europe.

On Wednesday, Lego reported a 13% increase in sales to 31 billion krone in the first half of this year and said the company had “significantly overtaken the toy industry and gained market share”.

Operating profit rose 26% to a record 8.1 billion krone after the group launched around 300 new sets of its top performers, including its iconic sets. The range includes a Lamborghini kit for £259.99 and the Eiffel Tower for £554.99, as well as toys from Technics, Star Wars and Harry Potter.

Christiansen said: “Our portfolio continues to be relevant for all ages and interests, and this is driving significant demand across all markets. We have leveraged our solid financial base to further increase spending on strategic initiatives that will support growth now and in the future, so we can bring playful learning to even more children.”