No. Times are awareness-level estimates compiled from public sources; sunlight, temperature, oxygen, and abrasion strongly affect rates. Plastics often fragment into microplastics rather than fully mineralizing. Use this tool for education—not for compliance decisions.

What does the environment setting do?

It applies a simple multiplier to approximate faster weathering at sun-exposed beaches and slower breakdown in cold, dark seafloors. You can view the multiplier under Advanced.

Do plastics really disappear?

Most common plastics fragment into microplastics; complete mineralization to CO₂ and H₂O is extremely slow or unknown for many polymers in marine conditions.

Ocean Plastic Decomposition Timer — Visualize Estimated Fragmentation Times

Friendly, awareness-level estimates. Private by design — runs locally in your browser.

Choose Items & Settings

Quick search Environment Timeline span (years)

Advanced (optional)

Environment multiplier (×) Years per second (play speed) Round results (decimal places)

Multipliers approximate faster weathering on sunny beaches (×0.6–0.8) and slower in dark, cold depths (×1.2–1.6). Adjust to explore sensitivity.

Note: “Decomposition” here mostly means fragmentation into microplastics; full mineralization is rare/unknown for many polymers in the ocean. Times are rough ranges.

Items

Timeline

median range exceeds span

Item	Range (years)	Median (years)	Notes

5 Fun Facts about Ocean Plastic Breakdown

Sunlight = crumb-maker

UV light snaps plastic chains so items get brittle and crumble faster at the surface or on beaches. In the cold, dark deep sea, the same plastic can last far longer.

Sunlight speeds up

Bottle ≠ bottle cap

A PET bottle and its HDPE/PP cap weather differently. The cap floats and embrittles in sun and waves, while the bottle body can persist for centuries.

Different plastics

Foam doesn’t “melt away”

Foam cups (EPS) tend to shatter into beads rather than dissolve. Those tiny beads can drift and linger as microplastics.

Not dissolve

Fishing line is a marathoner

Nylon fishing line and netting are tough and often shaded underwater, so they can take many centuries to fragment—much longer than thin bags or wraps.

Tough nylon

“Biodegradable” needs the right home

Some compostable plastics break down in hot, oxygen-rich composters—but in the cool, salty ocean they can still stick around for a long time.

Context matters

What This Timer Shows

The graphic compares awareness-level fragmentation/decomposition ranges for common plastic items in marine settings. Sunlight (UV), heat, oxygen, and abrasion speed up fragmentation; cold, dark, low-oxygen conditions slow it down. Most plastics don’t truly “go away”—they break into smaller pieces (microplastics/nanoplastics).

Median vs. range: We plot a median estimate with a shaded range to reflect uncertainty.
Environment: Use the dropdown to approximate faster/slower conditions; adjust the multiplier in Advanced to test sensitivity.
Timeline: Increase/decrease the span to fit very long-lasting items (hundreds of years).

Educational use only. Values are compiled from public awareness sources and literature summaries; real outcomes vary widely by polymer chemistry and conditions.