400 YEARS.... !
In a clean dry place out if the sun, never!
Plastic made from fossil-fuel oil never decomposes. It may break down into tiny pieces of plastic after some time, and may even be eaten by animals and insects, but styrofoam and other plastics do not decompose.
420 years ,
250 years;-)
One (1) month, 25-40 years, 50-450 years, and 50 years are the time that it respectively takes a banana peel, a leather shoe, a plastic jug, and a styrofoam cup to decompose. But the length responds to access to proper levels of air, heat, light, micro-organisms, and moisture.
It takes a paper cup a month to decompose in a back yard compost. It takes six weeks in the ocean.
A plastic cup can take 50-80 years to decompose.
A red solo cup will decompose in 50-100 years. Decomposition of plastic varies based on what type it is made from
a cup made out of styrofoam...........................................................................................................................................................................
Ceramics effectively don't "decompose". They can get crushed into powder, but chemically speaking they're essentially rocks.
if its a small Styrofoam cup definitely not