All plastics are made from oil. With time, they fragment and generate micro-particles which will end up in the food chain.
How to make it
Collect, separate and cash plastic pieces.
Separate plastic by type and colours.
Then it needs to be ground, in order to obtain small granules.
Put them in big bags.
Place them in an extruder which will allow to create divers objects as shown in the following examples.
Make colored trash bins.
rulers, set square etc…
You can also use bottle lids to make chair leg covers.