I haven’t purchased these yet, but the description contains this claim: “FORID compostable trash bags are made of 100% plant starch material (PSM),bioplastics based on natural renewable plant starch extracts,and can be composted in backyard or home composting facilities. In the case of composting, it is released as water, humus and CO2 within six months and returned to the ecosystem to complete the organic cycle.”
Compostable Trash Bags - FORID 8 Gallon Garbage Bags 150 Count Trash Can Liners 30 Liter Unscented Medium Wastebasket Bags for Kitchen Bathroom Home Office Garbage Can (5Rolls/Green) https://smile.amazon.com/dp/B085NLYBNK/ref=cm_sw_r_cp_api_fabt1_xi-UFbDMC1H11?_encoding=UTF8&psc=1
Others I have looked at, I was disappointed to discover, are apparently made of some sort of oxy-enhanced plastic. So they break down faster, but still just into smaller bits of plastic. The ones I referenced above sound a lot better.