Compostable film is built from resins formulated and certified to break down into water, carbon dioxide, and biomass under defined composting conditions, typically the industrial composting standards referenced by certifications, with a smaller subset of formulations also certified for home composting. This is a meaningfully different claim than "recyclable" or "PCR content," and the distinction matters because compostable film generally cannot go into standard plastics recycling streams without contaminating them.
Compostable film formulations process differently than conventional polyethylene, with narrower temperature windows and different cooling behavior on a blown film line, and they typically carry a cost premium over both virgin and PCR polyethylene. Mechanical performance, particularly puncture resistance and seal strength, can also fall short of conventional polyethylene depending on the specific resin system used, so compostable structures need realistic performance testing against the actual application rather than an assumption that they perform identically to the film they are replacing. Buyers should also confirm their target market has access to industrial composting infrastructure, since a compostable claim provides little practical benefit if the package ends up in a landfill or a conventional recycling stream regardless.