Three years ago, Lego pumped $155 million into a new Sustainable Materials Center, which set more than 100 employees on the task of Lego using fully sustainable materials in its products by 2030. This month, the company showed off the first brick-based fruits of those efforts: About 25 different Lego shapes, many of them plants, will now be made from sugarcane-based polyethylene rather than oil-based plastic. It's an important milestone, but a relatively small one—which no one knows better than Lego itself.

By the end of the year, under two percent of Lego bricks will use the new polyethylene, a haul that includes not just bushes and trees but also the brushes in the car washes and street sweepers in the Lego City line, and at least one set of dragon wings. While the percentage sounds small, keep in mind that Lego sells 75 billion elements every year. Little pieces add up quick.

About 25 different Lego shapes, many of them plants, will now be made from sugarcane-based polyethylene rather than oil-based plastic.

But other numbers come to mind that may help put Lego's long-term sustainability challenge into even sharper perspective. The company makes more than 3,700 individual elements. It uses 20 different kinds of plastic to make those bricks, tires, and adorable minifig helmets. And as many as 80 percent of Lego pieces consist of acrylonitrile-butadiene-styrene, or ABS, a petroleum-based substance that polyethelene can't hope to replace. In fact, it's still unclear if anything can.

If anyone knows how to methodically piece together a solution from a range of disparate parts, though ... well, you get it.

Plant Matters

Let's start with the good news. Those bushes and trees really are a big deal. It took about two years for Lego to settle on the sustainable polyethylene that goes into them, which uses ethanol produced from sugarcane rather than petroleum. That time was spent sourcing, testing, and perhaps most importantly figuring out how to produce the bricks in quantity.

All that work goes toward not improving on existing oil-based elements, but precisely replicating them.

"You never notice the difference. That is what our fans, young and old, are obviously concerned about as well," says Tim Brooks, a Lego vice president who heads up environmental responsibility efforts. "In this occasion, what we've produced has exactly the same durability, quality, and safety as we have today."

As far as replacements go, though, it's low-hanging fruit, which Lego readily acknowledges. Plant-based polyethylene won't be invading any of Lego's load-bearing elements; you don't stack trees or dragon wings. All it needs to do, really, is stand there and look pretty. "It's much softer, it has more of a matte finish, it's more flexible, it doesn't require that very tight tolerance that a brick does to stick together," says Brooks.

Another obvious but potentially undersold benefit of bio-polyethylene? It already exists.

"This is good for the short term, because they're using materials that are available now," says Gihan Hewage, who follows bio-based materials and chemicals at Lux Research. "This is a very isolated step in the grand scheme of what they're doing."

Even the production process, Hewage says, should transition smoothly. Aside from a higher materials bill, the polyethylene swap won't cause much of a hassle.

So! One oil-based plastic down, just 19 to go. Except, as you may have guessed, it's not quite so simple.

The ABS Blues

It's important to note that exact bioplastic replacements for the majority of Lego's remaining stock do not exist. Not yet, anyway, and those materials are certainly not available at a scale that can produce tens of billions of precisely fitting shapes each year.

Indeed, Lego can't reach its 2030 goal without solving ABS, a material that affords the company the attributes it so prizes: Durability, color fastness, strength, and clutch power, or how well two joined bricks stay together. Plenty of plant-based plastics exist, but none checks all of those boxes.