We all want to be responsible consumers and limit our environmental impact. Composting food scraps and yard waste is a great start, but it's critical to understand what materials belong in home compost piles. There is much confusion around compostable and biodegradable plastics and packaging. This article provides clarity on proper composting methods for common packaging materials.
Several key factors determine if an item can successfully break down in a compost environment:
Petroleum-based plastics - Typical plastic bags, containers, and packaging. These do NOT decompose in compost piles.
PLA plastics - Made from corn starch or sugar cane. May decompose in commercial facilities, but NOT in backyard composters.
Paper and cardboard - Must be free of plastic coatings or linings to break down. Waxed paper and paper cartons contain plastic barriers.
Backyard compost piles reach 90-140°F max during decomposition. This is often insufficient heat for many compostable plastics to break down.
Commercial facilities use higher heat - 131-170°F is needed for proper PLA plastic composting.
Even certified compostable plastics can take months to years to fully decompose.
Backyard composters rarely achieve ideal conditions for thorough breakdown.
Follow these best practices when managing common packaging items:
NO plastic bags in compost bins - they won't break down and contaminate compost.
Recycle eligible plastics where possible. Check your municipal guidelines.
Trash non-recyclable plastics. Don't wish-cycle or try backyard composting.
Cartons - Remove plastic spouts and recycle paper portion only.
PLA-lined cups - Trash cups or recycling if accepted in your area. Don't compost.
Certified commercial compost only - Do NOT place in backyard composters.
Check labels closely - not all bio-plastics are backyard compostable.
When in doubt, trash compostable tableware and bags. Contamination risk is too high.
Can I put any type of plastic in my compost bin?
No. No conventional petroleum-based plastics belong in home compost piles. Even certified compostable plastics should go in commercial organics bins only.
What about compostable bin liners and bags?
Do not use any plastic bags to line compost bins, including ones labeled compostable or biodegradable. These need intense heat and controlled conditions to break down.
Is it safe to compost in plastic containers?
Yes, you can use plastic bins, tumblers, and holding containers to collect and compost waste. Just don't place the plastic itself into the final compost pile.
How do I know if packaging is truly compostable?
Look for BPI or Vinçotte certification logos and language approving use in commercial organics collections. Don't assume home compostability without clear guidance. When unsure, leave it out of backyard compost.