Black plastic and other bin liners are made from petroleum or natural gas, both non-renewable resources, and can take anywhere from fifteen to a thousand years to degrade.
Plastic bin liners cause the same environmental problems as single-use plastic bags (which the Government introduced legislation to ban, effective 1 July 2019).
A useful article here from Method on different types of bin liners: degradable, biodegradable, home compostable, commercially compostable ...
See plastic bag
Reduce the quantity of plastic bin liners needed by:
Wash and reuse plastic bin liners as much as possible.
Keep plastic from landfill wherever possible.