There are many different kind of plastics.
PFAS like PFOA for example is not even a plastic but a material to process and utilize other materials like for example teflon (PTFE) in a factory.
I do not fully agree that those microplastics arise from plastics in the home. It is usually the byproduct or waste product during the manufacturing of plastics or the burning and incineration of the plastics, without using any kind of smoke filter in the chimney. And dumped in open sewers and in open air.
See post #73 of this thread i made explaining PFAS dumping, C8 dumping, GenX dumping and PFOA dumping:
Page 3 - Seeking answers? Join the AnandTech community: where nearly half-a-million members share solutions and discuss the latest tech.
forums.anandtech.com
The plastics in your home and my home can degrade when there is for example not a material added to the plastic to make it UV resistant. If such materials are not added, the plastic will breakdown, become brittle and fall apart, pulverizing in tiny specs. That is true, but that is the result of a bad manufacturing process. UV resistant plastics are very common these days.
There are Thermoplastic materials like PVC, PE, PA ,PS ,PP ,PMMA , and UHMWPE (Dyneema plastic). Kevlar. And there are Thermosetting materials like, UP ,EP ,SI, UF.
What is not well known is that there exist bacteria on land but mainly exist in the sea that happily break down plastics. Also those microplastics. These are the same kind of family of bacteria that breakdown oil in the sea and the same bacteria consuming oil, methane(CH4) or carbondioxde(CO2).
Even from man made oil spills are consumed by these oil consuming bacteria, like in the vicinity of deepwater horizon is happening.