Decomposition Rates

paper ~ 2.5 months
orange peel ~ 1-6 months
cigarette butt ~ 5-6 years; chemicals also leach into water and poison wildlife
milk carton (cardboard) ~ 5 years
plastic bag ~ 10-20 years
plastic cup lids, utensils ~ 20-30 years
metal bottle cap ~ 50 years
foamed plastic cups, plates ~ 50 years
disposable diaper  ~ 75 years
plastic bottle ~ 100-400 years
tin can ~ 50-100 years
soft drink can ~ 200-500 years
monofilament fishing line ~ 600 years
glass beverage bottle ~ 1 million years
styrofoam ~ never
Sources: Keep America Beautiful, Louisiana Department of Environmental Quality.