New research in Britain has found 60 percent of "compostable" plastic did not fully break down in home compost bins.
The paper in the Frontiers in Sustainability by University College London researchers also found consumers were often confused about the meaning of the labels of compostable plastics.
The team surveyed more than 1500 participants from across the UK over two years, asking them to track material in their compost bins.
They concluded that home composting is not an effective or environmentally beneficial waste processing method.