LEGO, which is targeting 2030 for the swap, says the replacement material needs to be strong; have “clutch power” so LEGO pieces can snap together and apart; and be resistant to color fading.
Hewage says acrylonitrile butadiene lignin—which was recently unveiled by Oak Ridge National Laboratory scientists who replaced the styrene in ABS with lignin—may be an option. ABL’s performance characteristics are in line with LEGO’s needs, but it lacks the “sustainability angle” LEGO is targeting because the acrylonitrile and butadiene would still have to be produced petrochemically.
Polyhydroxyalkanoate is also a potential replacement. “[M]inimal progress” has been made in improving PHA’s properties, but these could change by 2030, Hewage says. “Moreover, Italian-based Bio-on independently developed its “minerv super toys” that bear a striking resemblance to LEGO’s iconic bricks. While these toys, in their current state of development, likely do not fulfill LEGO’s stringent materials requirements, they do suggest that LEGO can develop a useable PHA by 2030,” he adds.
Hewage also considered polylactic acid, given PLA’s “similar process-ability” to ABS and large production capacity already available, he writes on Lux’s blog. “However, given the poor performance demonstrated by PLA in applications thus far … we only anticipate it to grow at a CAGR of 3.2% over the next decade, reaching 590 KMT in 2026.” Thus, it would be unlikely LEGO could develop PLA with sufficient performance, even by 2030.
LEGO faces a “long journey to adoption,” Hewage concludes. “However, [the company] is smart to emphasize performance to enable sustainability in its bricks of the future, as this gives them the best chance of success.”