An Australian Senate report in April on the Toxic tide: the threat of marine plastic pollution, found that so-called degradable and biodegradable and plastic shopping bags contain additives that make them disintegrate more quickly than traditional plastics and turn into harmful smaller particles until they become microplastics – tiny plastic fragments less than five millimetres in size.

When microplastics enter the marine environment they can choke seabirds, poison wildlife and accumulate up the food chain, turning up in seafood eaten by humans.

A Senate committee recommended that the Australian Government actively support research into the threat posed by marine plastic pollution, particularly microplastic, on human health and marine animal health.

“The committee also notes that there is some community confusion regarding the differences between biodegradable, degradable plastic, compostable and traditional plastic. Of particular concern is the lack of understanding about the ways in which these items should be disposed of, and the end product,” it said.
“While consumers might feel they are ‘doing the right thing’ by choosing biodegradable or degradable plastic, these products simply disintegrate into smaller and smaller pieces to become microplastic.”

The committee said the term “biodegradable” could also refer to “fully biodegradable” or “compostable” plastics generally made from plant materials which return to base organic components when processed by commercial composting facilities.

The warning has prompted a Senate committee to also call for source reduction strategies and a public awareness campaign to explain the differences between degradable, biodegradable, compostable and traditional plastic bags and how they should be disposed of.

The committee also recommended that the Australian Government move to immediately ban the importation and production of personal care products containing microbeads.