We produce and consume them by the millions of tons, our societies depend on them, they are found everywhere and they will last for thousands of year.
I What are plastics?
To speak about plastics, we first need to introduce the concept of polymers. A polymer is a group of units called monomers, linked together by chemical bonds. Those monomers are small molecules (formed by atoms). A good example of a natural polymer is rubber: the sap from the hevea tree forms a polymer when exposed to oxygen from ambient air.
A plastic is a synthetic polymer mixture, molded, usually upon heat and pressure, in order to form an object. There are different types of plastics:
- Thermoplastics, which melt when hot and solidify when cold in a reversible manner. They are mainly used for packaging (see detail of their uses by the Ellen MacArthur foundation below);
- Thermosetting polymers, where this transformation is irreversible. Textures and uses vary, from foams used in mattresses to thermal insulating materials used in kitchenware (pan handle, etc.);
- Elastomers, that can deform under physical constraints and go back to their initial shape: typically latex (disposable gloves) and rubber (tires, etc.).
Plastics are part of our daily life: they are everywhere, in our houses, furnitures, electronics, sport gear… In particular, thermoplastics account for about 85% of today’s total plastic production.
Source: Plastics Europe
II The plastic problem
Why and how did plastic become a problem?
Manufacturing: polluting and energy consuming
Stunning, ever-increasing quantities
Source : Plastics Europe
Ocean pollution: 15% of plastic waste end up contaminating natural sites
- Further to visible damages (hurt or dead animals), what is the impact of ingesting micro-plastic on marine animals and their ecosystems?
- Is ingesting those plastics — through consuming fish and seafood — toxic for humans?
- Considering their durability and ease to travel, can these particles be a new vector for pathogen propagation between continents?
What are the solutions to limit pollution?
– Government initiatives regulating packaging plastic usage, for example:
- Plastic bags: on regulation, the leader is Africa, with complete ban imposed in Rwanda (2004), Eritrea (2005), Tanzania (2006), Mauritania (2013), Morocco (2015), Senegal (2016), and Kenya (2017), and partial ban/taxes imposed in 15 more countries. In Europe, Italy (2011) was the first European state to completely ban single use plastic bags. Since then, the European directive on plastic bags is transforming the industry. UK imposed a tax on plastic bags in 2015, leading to a 85% decrease in consumption in a year; in France, a ban of single-use plastic bags was adopted in July 2016. Finally, in Asia, India (2002), China (2008), Myanmar (2009), and Bangladesh (2002) have instituted partial to full bans.
- In cosmetics, new bans are aiming to reduce plastic use and waste: for example, microbeads will be banned by the end of 2017 in the UK. In France, the Biodiversity Law will result in a ban of microbeads and plastic cotton buds, respectively from the 1st of January 2018 and 1st of January 2020.
- Plastic bottles: the city of Bundanoon (AUS) pioneered plastic bottle ban in 2009. In 2013, Concord (Mass., USA) followed the lead. But the first strong action was San Francisco’s ban in 2016. Since then, many cities announced targets to reduce selling or at least stop funding bottled water; student initiatives also allowed to ban selling bottled water in Universities, such as in Leeds (UK), where water fountains were installed in 2008.
– Recovery can be either material (recycling), energetic (incineration) or chemical (depolymerisation).
Read the next article: plastic waste recovery.