Complicating the problem of plastic pollution is the fact that there are many different types of plastic out there. Some are hard and inflexible like a bottle of Coke, while others are soft, such as plastic bags. While all of them are usually oil-based, they go through different production processes. In the process, different chemicals are added to produce different characteristics, for example hard versus soft plastic.
Because of the differences in production process and product characteristics, plastic products cannot be simply put into one container and recycled. For them to be recycled (which tends to be down-cycling!), each type needs to be sorted (typically this includes even sorting out different colors) and then processed in different ways. This makes recycling plastic very challenging and means that the bulk of plastic ends up in landfills or is burnt in incinerators.
Why and how to avoid PVC and polystyrene
Previously I wrote about one specific type of plastic, namely thermoplastics. Loads of products are thermoplastics, but the worst offenders are products made of PVC and polystyrene. In order to avoid these two, always check the product for the triangle with a number in it.
Number 3 is PVC. This type of plastic contains lead and produces dioxin when burnt. Both are dangerous for our health and the environment. Number 6 is polystyrene. When heated, chemicals such as styrene and benzene may leak into the food. Both are carcinogenic and hormone disrupting substances. If you want to cut down your plastic consumption and waste, avoiding these two is a great way to get started!
For PVC, that means avoiding cling film (use a food container or simply put a plate on top of a bowl) and toys made of plastic. Especially bath toys are notorious for containing pvc. In terms of more durable products, rain jackets, bags, and other outdoor gear may also contain pvc. Try to find the product second-hand so that no new pvc is needed or find a pvc-free alternative.
Avoiding polystyrene means avoiding disposable plates, lids on take-away cups, disposable cups that are used in coffee machines at work, and plastic trays for French fries (commonly used in the Netherlands). Whenever you order stuff online, request the package to be free from styrofoam. When going to a party, #BringYourOwn reusable plate, cup, and cutlery. Get your own reusable cup for coffee at work and on the go.
You might be walking and sleeping on plastic!
This week I want to talk about a different type of plastic: thermosets. This type of plastic is used in a range of products, for example mattresses, shoe soles, and as a coating on whiteboards and golf balls.
To find out whether you too are walking or sleeping on plastic, always check the labels of a product you buy. When you shop online, look at the product specifications. If the website or product label does not explain what the product is made of, ask the salesperson or send an email about it. This will not only help you to make an informed choice, but also helps create awareness on the side of the seller and/or producer that customers want to know what they buy.
As with all kinds of plastic, there are plenty of reasons to avoid thermosets. Here are the three most important.
1. Most plastics are made from crude oil
Just like thermoplastic (including pvc and polystyrene), thermosets are also made of crude oil. Depending on the kind of thermosets that will be made, two components are brought together in a mould, accompanied with for example an acid. After a chemical reaction has taken place the thermoset is formed. A new component is made.
Oil is a non-renewable product. We only have so much of it. Therefore, if we use it, we should do so wisely. Also, it takes a lot of energy to drill for oil and causes a lot of environmental and social damage. Best to limit our use of this precious resource.
2. Plastic = crude oil + chemicals
During the production process, chemicals or energy are added to the crude oil. Liquid components are poured into a heated mold. Due to the heat and/or chemicals, cross links are formed. Cross-links are bonds that tie the substance irreversibly together.
The three dimensional network of bonds in thermoset plastics is generally really strong. Therefore, the material is better suited for high-temperature applications up to the decomposition temperature. However, they are more brittle.
The chemicals that are added to the crude oil are not necessarily safe for our health and the environment.
3. Not re-cycling, but down-cycling
Since their shape is permanent, thermoset plastics tend not to be recyclable as a source for newly made plastic. Thermosetting plastics cannot be melted into new products. But it can be reused for example by shredding it into small flakes.
Flexible polyurethane foams are commonly shredded into small flakes and re-manufactured into carpet underpayment. With this process a lot of the original product will be wasted and should thus be regarded as down-cycled material as opposed to re-cycled material.
Thermosetting plastics can’t be heated to reuse and reshape it again. When heated with very high temperature it will carbonize just like wood when heated.
Ok. So thermoset plastics are bad. What can I do?
Thermoset plastics are used in a wide range of products. Thankfully, you generally won’t find them as packaging or disposable products. There are used in products such as mattresses, shoe soles, and whiteboards.
When you have thermoset products that you don’t need anymore, always try to sell or give away them first so that the product gets reused and they don’t end up in an incinerator or landfill before their end of life.
Likewise, if you really need to buy a thermoset plastic product, try to find it second-hand.
Because thermoset plastic can only be heated and molded once, it normally is not recyclable. However, thankfully, there are some organizations out there that are engineering solutions to this problem. For example, for the disposal of mattresses in Europe, check with the company RetourMatras to see if there is a possibility to recycle it. Especially for larger purchases such as a matrass or a whiteboard, ask the salesperson (if bought new in store) how to eventually dispose of the product. There might be some kind of collection and disposal scheme.
So, wherever you can, try to #refuse (ask yourself: do I really need this product?), #reduce (maybe one pair of shoes is sufficient), or #reuse (find the product second-hand). Also brainstorm for alternatives. You don’t have to buy plastic products. Often there are plastic-free or less harmful products out there.
Wish you all a happy Plastic-Free Tuesday! If you have any questions about plastic products, please leave a message below and I will try to answer.
Welcome back to the next episode in the Plastic Crash Course!
This post was written by Barbara, a chemical engineer living in the Netherlands. She was in charge of the crash course Plastics: The Basics. Barbara writes about what plastic is, where it comes from, what the difference between a plastic bottle and plastic wrap is, and what to think of chemical additives such as BPA.