Some of the different types of plastic to be aware of

Bioplastics:

Bioplastics — sounds good, right?

Especially when most plastics come from fossil fuels. Bioplastics, on the other hand, may come from plant-based sources, such as flaxseeds — and companies are often eager to use this as a selling point.

However, as the 2015 United Nations report states, once the polymer is created, the material properties are the same. In other words, the resulting material is no better than any other form of plastic.

Bioplastic or not, it’s still wise to cut down on our plastic consumption wherever possible. Bioplastics also can’t be recycled — nor can they be composted.

Compostable plastics:

Compostable plastic is very similar to biodegradable plastic, except to achieve ‘compostable’ status, it must be monitored and verified by an independent third party organisation.

However, being virtually the same as biodegradable plastic, compostable plastic still poses the same challenges when it ends up in our oceans. Nearly all UK organic waste treatment facilities can’t treat this material and will take it out as a residue sent for incineration or landfill.

The above three types of plastic all emphasise that the best way to reduce plastic waste and pollution is to simply cut down. More specifically, we should be focusing on eliminating the use of single use, unrecyclable, and not recycled plastic (think takeaway  cups, polystyrene food trays like ‘clam shell’ boxes and carrier bags).

Biodegradable plastics:

Biodegradable plastics (plastics that can be broken down into carbon dioxide, water, and minerals through natural processes) are another seemingly appealing alternative.

To use the term ‘biodegradable’, products must conform to national or international standards. In Europe, for example, for a plastic product to be deemed biodegradable it must:

· Not contain high levels of heavy metals

· 90% of the plastic must break down into CO2 within six months of being exposed to natural processes (including sunlight and hydrolysis)

· 12 weeks after exposure, 90% of the plastic leftover must be able to pass through a mesh measuring 2 x 2 mm

· The final material must not prove toxic to plants

Despite this, the speed of degradation depends heavily on the type of plastic and the environment it’s in. It often does not degrade properly.

Treatment plants for organic waste, such as in-vessel composters or anaerobic digestion facilities cannot treat these plastics, since they either disrupt the treatment process or simply take too long to biodegrade. These plastics also need a certain constant temperature range for a prolonged period in time in order to breakdown. In reality, the ocean’s temperature is vastly different, which will affect the rate at which the plastic biodegrades.

Bioplastics don’t solve the problem of plastic in the ocean, or prevent harmful microplastics from being produced.

Once in the ocean, UV radiation and wave action helps to break down plastic. However, once the plastic is submerged in deep water, where it can become covered in biofilm or buried in sediment (only 4%-5% of ocean plastics are found on beaches and shorelines), the speed at which the plastic can break down falls significantly.

The term ‘biodegradable plastic’ is clearly misleading, and certainly not a quick solution to tackling plastic pollution.