Decomposition times depend heavily on temperature, moisture, oxygen levels, sunlight exposure, soil microbes, and whether the item is buried, composted, submerged, or left exposed. The estimates below are generalized environmental averages.
Food & Organic Waste
Apple Core
- Compost pile: approximately 2 weeks to 2 months
- Natural outdoor environment: approximately 1 to 6 months
Apple cores decompose relatively quickly because they are high in moisture and biodegradable.
Banana Peel
- Compost conditions: approximately 2 to 5 weeks
- Natural outdoor conditions: approximately 1 to 2 years
Banana peels break down slower outdoors because waxes and fibers resist decomposition.
Mango Peel
- Compost pile: approximately 1 to 3 months
- Natural environment: approximately 6 months to 2 years
Mango peels are thicker and more fibrous than many fruit peels.
Orange Peel / Citrus Peels
- Approximately 6 months to 2 years
Citrus oils naturally resist microbial breakdown.
Bread
- A few days to several weeks
Bread molds quickly and decomposes rapidly when moist.
Eggshells
- Approximately 1 to 3 years
Eggshells are mostly calcium carbonate and break down slowly.
Paper Products
Newspaper
- Approximately 2 to 6 weeks
Thin paper decomposes quickly when wet.
Cardboard
- Approximately 2 months to 1 year
Wax-coated cardboard takes longer.
Paper Towel
- Approximately 2 to 4 weeks
Paper towels decompose especially fast in compost conditions.
Plastic
Plastic Grocery Bag (HDPE)
- Approximately 10 to 20 years to begin fragmenting
- Full breakdown may take hundreds of years
Plastic usually does not truly biodegrade. It breaks into smaller plastic fragments and microplastics.
PET Plastic Bottle
- Approximately 450 years or more
PET plastic, commonly used for water and soda bottles, is extremely durable.
Styrofoam / Expanded Polystyrene
- Possibly 500 years or more
Some estimates suggest expanded polystyrene is effectively non-biodegradable in normal environments.
Bioplastics / Compostable Plastics
- Industrial composting: approximately 3 to 6 months
- Natural environments: may persist for years if conditions are poor
Many compostable plastics require commercial or industrial composting facilities.
Metals
Aluminum Can
- Approximately 80 to 200 years
Aluminum oxidizes slowly but is highly recyclable.
Steel Can / Tin Can
- Approximately 50 years
Protective coatings can slow rusting.
Iron
- Approximately 10 to 100 years depending on moisture
Iron rusts relatively quickly in wet environments.
Glass
Glass Bottle
- Estimated at 1 million years or more
Glass is technically recyclable indefinitely but decomposes extremely slowly in natural environments.
Textiles & Clothing
Cotton Shirt
- Approximately 1 to 5 months
Natural fibers decompose relatively quickly.
Wool
- Approximately 1 to 5 years
Decomposition depends on thickness and environmental conditions.
Polyester Clothing
- Approximately 20 to 200 years
Synthetic fibers behave similarly to plastics.
Wood & Natural Materials
Untreated Wood
- Approximately 1 to 3 years
Moisture and fungi accelerate decomposition.
Treated Lumber
- Decades
Chemical preservatives slow decay.
Cigarette Butts
Cigarette Filter
- Approximately 10 to 15 years
Many cigarette filters are made from cellulose acetate plastic.
Disposable Hygiene Products
Disposable Diaper
- Approximately 250 to 500 years
Disposable diapers contain plastics, absorbent polymers, and synthetic materials.
Wet Wipes
- Approximately 100 years if plastic-based
Many flushable wipes contain synthetic fibers.
Important Environmental Notes
1. Biodegradable does not always mean fast decomposition. Some items only break down under industrial composting conditions.
2. Plastic rarely disappears completely. It usually fragments into microplastics instead of fully biodegrading.
3. Landfills slow decomposition. Lack of oxygen can preserve materials for decades.
4. Composting dramatically speeds up decomposition. Heat, moisture, oxygen, and microbes accelerate breakdown.