Degradable Plastic

By Ian Hall

“We only use biodegradable plastic”. This was a claim made by a resort hotel in support of their responsible tourism policy. Upon further investigation the claim was clarified to mean degradable plastic.

Some plastics marked as ‘degradable’ might not be as environmentally-friendly as consumers think. The implications go beyond greenwashing. In our rush to damn plastic bags and bottles, environmentalists may have compromised efforts to recycle.

Degradable plastic turns out to mean that the plastic will quickly break down into small pieces under influence of light and oxygen. This seems like a good idea given concern about the volume of plastic waste that ends up in landfill or in the sea.

The problem is that these small pieces are still not necessarily biodegradable and it is unclear how long they will persist in the environment and whether they are harmful. Sea turtles may not choke on a discarded degradable plastic bag but there is still a risk that plastic residues that they ingest will be toxic.

The alternative to plastic packaging is paper or reusable fabric bags. Hygiene concerns aside, life cycle analysis shows that it is too close to call which is more environmentally friendly. The debate about pollution by plastic bottles, bags and packaging has therefore reached the point where most are agreed that it is not the plastic itself which is the problem as much as how we dispose of it.

Plastic is recyclable so throwing it away not only causes pollution but wastes a valuable resource.

The real disaster of degradable plastic is that when it is mixed with other plastics during recycling, the end product will be worth less. This would make recycling of plastic less effective and is an unfortunate side effect of environmentalist’s ban-the-bag campaigns.

Surely a ban on degradable plastic would be more appropriate and the issue of non-degradable plastic tackled through recycling incentives and/or a switch to truly biodegradable or compostable plastic?

The latter may not be derived from petroleum at all and can instead be made from plant based products such as corn starch upon which bacteria are happy to chomp. Corn starch bags are being trialled by my colleagues at Borneo Rainforest Lodge and the sample I have been given has held up very well.

The moral of the story? People, like water, will take the path of least resistance. It’s easier to keep producing plastic packaging and to add a little extra to the mix than to change to an alternative product. It’s easier still to believe the greenwash.