Lego recently announced that it was winding down a program to recycle polyethylene terephthalate (PET) bottles into Lego bricks. The announcement, which was relatively brief, stated that the carbon emissions of switching over to the new process would have ultimately been greater than the carbon emissions of its current process. The announcement got a headline in the Financial Times and ultimately sparked a fair amount of social media buzz, necessitating a notes-app-style explanation from Tim Brooks, Lego’s VP of sustainability. Before I get into critiquing Lego, I do want to say that I appreciate its transparency and commitment to sustainable raw materials, which dates back almost a decade at this point.
I want to break down some of the claims here and then talk a little bit more broadly about Lego’s sustainability journey. Lego’s claim that the PET recycling process ultimately resulted in higher carbon emissions is a little hard for me to swallow: Baseline PET recycling has around 50% of the carbon emissions of primary PET; in addition, acrylonitrile butadiene styrene has roughly 50% more carbon emissions than primary PET, so Lego should be starting from a roughly 2/3 reduction in carbon footprint. Additional processing to improve the performance would certainly add to that carbon footprint, as would any sort of additive or other chemical necessary, but it’s just hard to imagine that this would add another 2 kg/kg of carbon emissions. A substantial yield issue could potentially create these kinds of carbon emissions — that is, if it had to process 4 tonne of waste to produce 1 tonne of usable material that would drive it into the red. It’s possible that building out new tooling and other equipment needed to process these materials into bricks would also add to the footprint, but these emissions are typically amortized over the life of the equipment and don’t really contribute that much to carbon footprint unless you’re only looking at the very near term.
It’s more likely that Lego was unable to make the PET meet its exact performance specifications. Lego bricks are, famously, precisely manufactured and durable: Even bricks from 50 to 60 years ago work very well. It’s likely in my mind that it just simply couldn’t get the PET to perform the way it wanted. Last and least interesting would be cost; Lego had a down year last year and this could just be a way to save some money. This is pretty unlikely, at least in the context of its claimed commitment to larger sustainability funding.
But beyond all that, the biggest reason why this effort failed is that it never made much sense from the start. PET was clearly chosen as a feedstock material because it’s widely collected, but it also has very well-established markets. There are challenges in PET recycling such as the yield of food-grade PET, but absorbing more bottles into non-bottle applications doesn’t really help with that. If Lego had been using a plastic with a very low recycling rate like waste polypropylene, this would have made a lot more sense, as there’s real value in creating new sources of demand for these types of materials. I think these constraints were knowable when Lego started this effort, so this is a failure of Lego’s innovation process. More broadly, waste isn’t really an issue for Lego: Legos themselves are durable and tend to not get thrown out — hand-me-down Legos are quite common. The goal of Lego has been to source its materials sustainably rather than to manage end-of-life issues; in this context, it should stick to its efforts to produce biobased drop-in plastics, like the bio-PE it uses in some of its plant parts. As for the backlash, it will just have to get used to it: Failed sustainability efforts are part of the journey, and it’s almost certainly going to fail again before it reaches its 2030 goal of 100% sustainable sourcing.
