A beginning, middle and long end

Beginning

A (very) quick chemistry lesson:

Plastic is made by melting small plastic resin pellets which take their origin from natural resources like coal, natural gas and oil (see the video below). This forms strong chemical bonds which can be categorised into two main groups:

• Thermoset (which, once moulded, cannot be melted because the chemical bond is irreversible. For example, bath tubs)

• Thermoplastic (which, due to its reversible chemical bonds, can be remoulded post-production by heating it up and can therefore be recycled. For example, plastic bottles)

Thermoplastics make up 92% of plastics and since this type of plastic can be recycled, there is no excuse to see it floating around the oceans!

Middle

Many plastics are used several times like children's toys but half of plastics we use are single-use plastics, so the 'middle' part of their life cycle is just a tiny moment, much like the flash of a camera. How long do you keep that straw? Or that packaging for the loaf of bread? Or that plastic bottle you bought from Tesco this morning?


Long end

The good news is that the straw you used at the bar last night and your plastic bottle from Tesco will decompose in the ocean! The bad news is that they will take up to 2 and 4.5 centuries respectively to do so. Check out more decomposition rates below:

(source: Ocean Conservancy)

Where do the plastics go once they enter the ocean? 

Quite simply: everywhere.

Even as far as the Antarctic. You can see for yourself on litterbase.awi.de the location of marine litter recorded from 1,426 studies which is focused mainly around coastal regions, but one can begin to make out the garbage patches in the 5 main gyres. The plastic doesn't just float on the surface or get washed up on coastlines, it can also stay in the water column or sink to the deep ocean through biological processes, the percentages of which we can see in this schematic:

(source: The Global Ocean Commission)

Below is an interesting video highlighting this life cycle. Bottle number 2 is the one I'll be focusing on for now and bottle number 3 in the coming weeks.

Which single-use plastics do you often find yourself using?