PLA (polylactic acid)

PLA is the best-known bioplastic: made from fermented plant starch, industrially compostable, used in food-service disposables, clear cups, 3D-printing filament and film. Its role in a recycling glossary is mostly cautionary.

PLA is not compatible with PET recycling: it looks like PET, sorts like PET to the eye, and ruins rPET at even low percentages — which is why PET bale specifications increasingly name PLA on the prohibited list, and why optical sorters are tuned to eject it. Nor does "compostable" mean recyclable in practice: PLA needs industrial composting conditions rarely available in mixed waste streams. Dedicated post-industrial PLA streams (3D-printing waste, converter offcuts) do trade to specialist reprocessors. Primary forms classify under HS 3907.70. In this corridor PLA appears mainly as a contaminant to be excluded, and as an enquiry-led niche stream when clean and single-source.