A plastic bag takes roughly 20 years to decompose — but long before that it has already broken into microplastics that scatter across land and water.
Why does it take this long?
Lightweight and easily blown by wind, plastic bags travel far from where they're dropped. In the ocean, animals mistake them for jellyfish and eat them. A bag used for minutes can harm wildlife for two decades.
Where it sits on the timeline
2 months
🍎 Apple core
20 years
🛍️ Plastic bag
20 years
🛍️ Plastic bag
4,000+ years
🍾 Glass bottle
Greener alternative
Switch to reusable tote bags
One durable tote replaces hundreds of single-use plastic bags a year — and never becomes 20-year litter.
Frequently asked questions
How long does a plastic bag take to decompose?
A plastic bag takes approximately 20 years to decompose in nature.
Are plastic bags biodegradable?
Standard polyethylene bags are not. "Biodegradable" bags usually need industrial conditions and rarely break down in open nature.
How can I reduce plastic bag waste?
Carry a reusable bag. A single sturdy tote replaces hundreds of single-use bags each year.
Sources and methodology
Decomposition times are approximate and vary substantially with material composition and environmental conditions. See the methodology and primary references used for this guide.