PLA filament can be recycled, but not through your curbside recycling bin. Most municipal recycling programs don’t accept PLA because it looks like other plastics yet contaminates conventional recycling streams. Your realistic options are grinding and re-extruding it yourself, sending it to a specialized mail-in service, or finding an industrial composting facility. Each path has trade-offs in cost, effort, and material quality.
Why Curbside Recycling Won’t Work
PLA is a bioplastic made from plant starches, and it behaves differently from the petroleum-based plastics that recycling facilities are built to handle. If PLA gets mixed into a batch of PET or HDPE, it ruins the entire batch. Sorting machines at most facilities can’t reliably distinguish PLA from conventional plastics, so they reject it outright or it ends up in landfill anyway. Even the “biodegradable” label is misleading here: in a landfill, only about one percent of PLA degrades after 100 years. It needs specific conditions to break down, and a landfill doesn’t provide them.
Grinding and Re-Extruding at Home
The most hands-on approach is turning your failed prints and support material back into usable filament. The basic workflow involves shredding your PLA scraps into small flakes, then feeding those flakes through a desktop filament extruder. Machines like the Filastruder, Felfil, or Artme 3D are designed for exactly this. PLA melts at around 180°C, and extrusion temperatures typically fall between 180°C and 230°C depending on the speed and your ambient conditions. A common starting point is 200°C, adjusting up or down in 5°C increments until the filament flows smoothly and holds a consistent diameter.
The catch is that PLA degrades each time you melt it. Research on multiple recycling cycles shows that tensile strength drops about 20% by the fifth extrusion cycle, with a noticeable decline starting around the third cycle. The material also loses ductility, meaning prints from heavily recycled PLA become more brittle. Blending recycled flakes with virgin PLA pellets (a 50/50 mix is common) helps maintain printability and strength, extending the useful life of your scrap material by a few more cycles.
A few practical tips make the process smoother. Keep your scrap PLA clean and dry, since moisture causes bubbles and inconsistent diameter during extrusion. Sort by color if you care about the finished filament’s appearance. And invest in a decent shredder or cross-cut paper shredder that can handle small rigid pieces; feeding large chunks directly into an extruder causes jams.
Mail-In Recycling Services
If you don’t want to invest in extrusion equipment, several companies accept PLA waste by mail and turn it into new filament or other products.
- Printerior (US, based in St. Louis): Accepts PLA, PLA+, and PETG. You pay for shipping, but local drop-off is free. For every kilogram you send, you earn 280 points toward discounted filament in their shop. At 1,400 points you get 50% off.
- TerraCycle (US, Canada, UK, and others): Sells a “Biodegradable Plastic Zero Waste Box” for PLA. A small box costs $177 and a large one runs $320, with shipping both ways included. It’s expensive for casual hobbyists but practical for makerspaces or schools generating steady waste.
- Recycling Fabrik: Accepts PLA and PETG. Free shipping labels are tied to purchases from their store, and you earn points redeemable for up to 25% off their recycled filament. They also offer closed-loop programs for businesses.
- Refactory (UK only): Offers recycling boxes at 60, 90, and 110 liters, starting at about £72 with a shipping label included (up to 20 kg).
- 3D Printing Waste (UK only): PLA only. Boxes range from about £54 to £168, but you don’t receive any credit or filament in return.
For individual hobbyists, the economics of mail-in recycling are tough. You’re often paying more in box fees and shipping than you’d spend on a fresh spool. These services make more sense for schools, libraries, and print farms that accumulate large volumes of waste and want to keep it out of the trash.
Industrial Composting
PLA is certified compostable under the ASTM D6400 standard, but that certification specifically refers to industrial composting facilities where temperatures reach thermophilic levels (above 58°C/136°F) and conditions are carefully controlled. Under those conditions, PLA breaks down in roughly 6 to 12 weeks. The problem is access. Not every municipality has an industrial composting facility, and many that do won’t accept PLA because it’s hard to distinguish from conventional plastic in the incoming waste stream.
If you want to try this route, contact your local composting facility directly and ask if they accept PLA. Some will, especially if you can confirm the material type. Don’t just toss PLA into a yard waste bin and assume it’ll get composted properly.
Home Composting Doesn’t Work
This is the most common misconception about PLA. A backyard compost pile rarely exceeds 60°C for sustained periods, and PLA needs prolonged high heat to break down. At ambient soil temperatures, PLA is essentially stable. Burying your failed prints in the garden or tossing them in a home compost bin means they’ll sit there largely intact for years, possibly decades. The “compostable” label on PLA packaging refers exclusively to industrial conditions.
Chemical Recycling
A newer and more promising approach breaks PLA all the way back down to its building block, lactic acid, which can then be used to manufacture fresh PLA with no loss in quality. This works through hydrolysis, where water molecules split the polymer chains apart. Under acidic conditions, the chains break from the ends. Under alkaline conditions, they fragment at random points throughout the chain.
One recent process uses mechanical ball-milling combined with alkaline hydrolysis under moist conditions, meaning it works at ambient pressure without external heat. The recovered lactic acid is then purified using a membrane-based electrodialysis system, which separates the acid efficiently without generating harsh chemical waste. Unlike mechanical recycling, chemical recycling doesn’t degrade the material with each cycle. The lactic acid output is chemically identical to what you’d get from fresh production.
This technology isn’t available to consumers yet. It’s being developed at the research and pilot-plant scale. But it represents the most realistic path to truly circular PLA recycling, where scrap filament could eventually be converted back into virgin-quality material indefinitely rather than losing strength with each pass through an extruder.
Choosing the Best Option for Your Situation
If you print regularly and generate a steady stream of waste, a desktop extruder pays for itself over time and gives you the most control. Expect to blend in some virgin pellets after the second or third cycle to keep print quality acceptable. If you only print occasionally, collecting your scraps in a box and mailing them to a service like Printerior is simpler, though you’ll wait longer to accumulate enough to make shipping worthwhile. Makerspaces and schools should look into Printerior’s or Recycling Fabrik’s bulk programs, which offer better value at higher volumes.
Whatever you choose, the worst option is the trash. PLA in a landfill barely degrades, contributing the same long-term waste as conventional plastic. Even imperfect recycling, where your filament loses some strength each cycle, keeps material in use far longer than a single print-and-discard cycle allows.