The world produces 381 million tonnes of plastic waste every year, a figure set to double by 2034. Some alternative materials have been hailed ‘silver bullets’ to the problem, but are they really a viable option?

But what exactly is sustainable plastic alternative? Is it recyclable, compostable, biodegradable, made from renewable materials? Better yet, could it be plastic made from captured carbon dioxide or other greenhouse gases? All of these options exist today, and quite a few are already on the market.

Biodegradable plastic is forecast to grow to more than $6 billion in market size by 2023 and the UK’s compostable packaging market is predicted to increase tenfold by 2025. But what’s the difference?

Biodegradable refers to the ability of a material to break down and return to nature. To qualify as biodegradable, packaging materials must completely break down and decompose into natural elements within a year.

Compostable materials go one step further by providing the earth with nutrients once the material has broken down.

Sounds great, but these materials aren’t without their problems.

Compostable packaging, for example, generally requires an industrial facility to heat the plastic to a high enough temperature for microbes to break it down, in combination with measured levels of oxygen and moisture. Home composting systems are simply unable to provide these conditions.

When sent to landfill, compostable plastics are deprived of the light and oxygen needed to decompose, and can instead release significant levels of methane, a greenhouse gas far more potent than carbon dioxide. In short, the results are virtually the same as traditional oil-based plastics.

Meanwhile, biodegradable items can break down within the environment with the help of bacteria or other living organisms, but this doesn’t necessarily mean they’re good for the environment. Some plastic bags can biodegrade into tiny pieces in around 20 years, but they are still harmful to the environment.

Both compostable and biodegradable packaging materials are still in the minority in the UK and most recycling plants are not yet equipped to deal with them, so despite the best of intentions, much of the compostable packaging we produce is still incinerated or sent to landfill.

For this reason it’s vital that any brand using these materials ensures the packaging carries clear labelling so consumers know how to dispose of the packaging correctly.

There are of course cost implications to switching from traditional plastics. Currently compostable and biodegradable materials cost more to produce, and if this cost is passed to the consumer they are less likely to buy.

Some biodegradable materials are two to 10 times more expensive to produce than comparable non-biodegradable materials. But as demand for these materials increases, the prices will fall.

While packaging that decomposes seems like a perfect solution to the ever-increasing plastics problem, we also need to consider the environmental impacts of creating – or rather, growing – the raw materials. Many industry experts already view bioplastics as a counter-productive solution and this should be considered when weighing plastic against compostable packaging.

As compostable plastics are made using biomass – such as corn starch, wood pulp, sugar cane, and wheat straw – there is much debate about whether creating high volumes of bioplastic is coming at the expense of our food supply.

But as we race to find the next big thing in food packaging, we must not lose sight of the importance of a circular economy. The traditional plastics already in circulation can be kept out of landfill if waste infrastructure is better able to collect and process them, and in our quest to reduce our reliance on virgin materials, this route should not be neglected.

Next time we examine how the pandemic have changed consumer priorities, and how this in turn will shape post-COVID packaging.