If plastic is the problem, is bioplastic the solution?

In June 2019, one of Japan’s largest retailers — convenience store chain Seven-Eleven — announced that it will be replacing the packaging of its rice balls (onigiri 🍙) with bioplastic.

🍙 Onigiri 🍙 lined up in Seven Eleven — a convenience store, or ‘conbini’ (Photo: Mariko McTier)

Considering that Japan has the world’s second highest rate of plastic packaging waste per capita in the world (second only to the US) and a study recently found 3 million plastic bags in Osaka Bay alone, this is welcome news. But, is bioplastic really the solution?

Despite its name, a bioplastic is not automatically a sustainable solution.

You might expect a bioplastic wrapper to break down on your compost heap, or to at least have a lower carbon footprint, but it might surprise you to find out that neither is necessarily true.

So as Japan (albeit cautiously) explores the viability of more sustainable plastic production and consumption, here are 4 facts about bioplastics to consider.

1 ) First things first…what is a bioplastic?

As you may have started to guess, ‘bioplastic’ is a confusingly vague term that can mean one or both of two things:

1. a plastic that is bio-based (i.e. partially or entirely made from biomass rather than petrochemicals) AND / OR

2. a plastic that is biodegradable (i.e. can be broken down by enzymes present in nature)

So far so good…?

In principle, a bioplastic that is either — or both — of the definitions above should be an improvement on the non-bio-based, non-biodegradable plastics that are currently most common. Either because it reduces our use of fossil fuels and CO2 emissions (bio-based), or because it will biodegrade more quickly (biodegradable).

But here are some of the reasons it may not be the panacea we might be led to believe.

2 ) Bio-based and biodegradable are NOT one and the same

Despite being made from organic materials, bio-based plastic may be neither…