Why do existing biodegradable plastics often fail to solve environmental crises in landfills?

They require specific industrial composting conditions to break down completely.

While the goal in material science is to create substances that perform perfectly during their use-cycle but then decompose entirely into inert, non-polluting compounds shortly after disposal, current biodegradable plastics fall short of achieving this universal environmental benefit. The primary limitation identified is that existing biodegradable materials necessitate specific conditions, namely industrial composting environments, in order to fully break down into harmless substances. Because these specialized conditions are not met in standard settings like landfills or the open environment, these plastics persist, failing to resolve the environmental contamination problems they were intended to address in those common disposal scenarios.