Within a circular bioeconomy, biodegradable bioplastics (BBPs) have been promoted in fast-moving consumer goods to contribute towards closed-loop material flows. Consumers play a key role as enablers of these flows, provided they accept, understand and dispose of BBPs appropriately. Informed by focus groups, a framework combining multiple behavioural and design theories was developed to identify and structure systemic factors influencing the flow of BBPs through the consumption phase, with a focus on disposal. An exploratory network analysis based on a survey of 457 and 284 participants from two universities in the United Kingdom and the United States was then conducted to explore the interplay between factors and intentions to dispose of BBPs in different waste streams. Access to adequate organic waste infrastructure and pre-existing knowledge of BBP terminology and disposal routes were most strongly associated with intentions to dispose of BBPs alongside food waste. Mapping and facilitating consumer behaviour in tackling BBP waste is pivotal in designing sustainable systems for these materials.