Episodes 30 and 31 - Plastic-free July
Plastic-free July
Like Veganuary, Plastic-free July is an awareness-raising campaign where people pledge to change their behaviour for a designated month of the year – but with the idea in mind that this will prompt lasting behaviour changes. It is run by the Plastic Free Foundation in Australia and claims to have “inspired over 250 million participants in 177 countries”. People can sign on to avoid single-used plastic packaging, to target the “top 4” takeaway items (bags, bottles, straws, and coffee cups), or to go completely plastic free.
What is Plastic?
The term “plastic” is derived from the Greek word “plastikos”, meaning fit for molding. Plastic is actually not one material – it refers to a range of synthetic or semi-synthetic materials that have the property of plasticity, meaning that they are capable of being moulded or shaped. Plastics also often have low density, low electrical conductivity, transparency, and toughness.
Plastics are synthetic polymers, which are materials made of long, repeating chains of molecules. (Natural polymers exist too and include rubber, wood, and proteins). Plastics are made from raw materials that make up the monomers. Then, monomers are transformed into polymers through polymerization. Then the polymers are processed into polymer resins and used to make final products.
Ethylene and propylene are two common monomers. They are by-products of the cracking process used in refining oil and natural gas. Plastic is the third most commonly used petroleum derivative in the world. 200 million tons of plastic are used annually worldwide.
History of Plastic
Horn and tortoise shell were used as early natural plastics, with the first recorded mention in 1284.
Alexander Parks in 1862 exhibited Parkesine (celluloid), the first commercial manmade version of plastic. It’s not widely used anymore because it is highly flammable and expensive to produce.
In 1907, Leo Baekeland invented Bakelite, the first truly synthetic plastic, was invented in New York. A Bakelite Corporation ad claimed that humans had transcended the old taxonomy of animal, mineral, and vegetable. Now the world had a “fourth kingdom, whose boundaries are unlimited.”[1]
In 1900-1920 casein plastics were developed by Erinoid, stockings made of viscose went into production, and Rolls Royce began to use phenol fromaldehyde in its car interiors.[2]
In 1929, Bakelite becomes the first mass produced plastic product (the phenolic moulding in the casing of the Siemens telephone). The 1930s is the start of the modern plastics era. Polyethylene is discovered in 1933.
Modern plastic got its start during WWII.[3] Plastics were used in parachutes, grenades, and airplanes, among other military products. After the war ended, plastics companies began marketing their material for consumers.[4]
Disposable plastics use accelerated beginning in the 1950s as part of the consumer revolution. By 1979 we were producing more plastic than steel.[5] And in recent years there has been a shift from durable plastics made to single-use plastics.[6]
Types of Plastic
Plastic can be divided into two major categories:
Thermoset plastics – these are plastics that, once cooled and hardened, retain their shapes and cannot return to their original form. They are hard and durable. (E.g., polyurethanes, polyesters, epoxy resins, phenolic resins).
Thermo plastics – these are less rigid plastics that can soften upon heating and return to their original form. They are easily molded and extruded into films, fibres, and packaging. (E.g., polyethylene, polypropylene, polyvinyl chloride).
Some Common Plastics
Polyethylene (PE) is the most common polymer in plastics. It was first made in 1934. You’ll see two main variants of PE today:
Low density polyethylene (LDPE) is the plastic used in grocery bags. It is also used in plastic film and bread bags.
High density polyethylene (HDPE) is a stiff plastic used for more robust plastic packaging like laundry detergent containers, shampoo bottles, and milk jugs. It is also the plastic used in things like trash bins.
Polyethylene terephthalate (PETE or PET) is the most widely used plastic in the world, and it is used predominantly in polyester, as well as for bottles and packaging. It is the main plastic in Ziploc bags and is also used in things like cake trays.
Polyvinyl chloride (PVC) is a strong, rigid, brittle plastic used in construction, like plumbing (pipe) and vinyl sidings. It is also used in mouthwash bottles and clear food packaging.
Polypropylene (PP) is semi-transparent and has a low-friction surface. It is used for things like cheese containers, syrup bottles, and yogurt containers.
Polystyrene (PS), or Styrofoam, is used in packaging. It’s also used in soft drink lids, takeaway containers, and medical devices like test tubes.
Polylactic acid (PLA) is a biodegradable plastic derived from biomass rather than petroleum.
Polycarbonate (PC) is a transparent material known for being strong relative to other plastics. It is used in greenhouses and riot gear.
Acrylic (PMMA) is transparent and scratch resistant, which is why it’s the material used in optical devices.
Acetal (Polyoxymethylene, POM) is known for high resistance to heat, abrasion, water, and chemical compounds. It also has a low “coefficient of friction”, which makes it useful in applications that utilize gears.
Nylon (PA).
Acrylonitrile Butadiene Styrene (ABS) is a hardy plastic that is easy to machine and has a low melting temperature. For that reason it is often used in 3D printing.
Polytetrafluoroethylene (Teflon) was invented in 1938 by DuPont.
Polyvinylidine chloride (Saran) is made by Dow.
Environment and Plastics
We introduced this topic briefly in the zero waste episode. We have produced 320 million metric tonnes of plastic, which is heavier than every human alive combined. And that figure is set to double by 2040. That’s a lot of plastic and we don’t have a good plan for dealing with it.
There are four main environmental problems with plastic.
Emissions: Plastic, a petroleum by-product, is contributing to climate change.
Pollution: The vast amounts of plastic we dispose every year in our packaging, containers, and clothing are polluting our land and water environments.
Animals: When plastic ends up in ecosystems it can kill animals who ingest it or become entangled in it. (Remember the starving albatross chick?)
Microplastics: Plastics shed microplastics, which get into our air, soil and water. In our laundry episode we talked about how plastic microfibres have been found in some of the most remote ecosystems on the planet. That is a problem because some of the chemicals in plastics may be (or have been shown to be) harmful or even toxic for animals and humans.
Recycling Plastics
Of all the plastic we’ve produced thus far, only about 14% has ever been collected for recycling and only 5% has actually ever been recycled. There are different estimates on how much plastic currently gets recycled, but the estimates are generally low. I came across one estimate saying only about 1/5 of plastic is recycled. Another said that only 1/7 of plastic packaging is recycled and the ratio is even lower for other kinds of plastic.[7]
Some plastics can’t be recycled, while others can be recycled but aren’t accepted in municipal curbside recycling (so you would need to use a special program).
When recycling plastics, it is important to rinse any food or grease from the plastic – especially if you have a mixed bin that has paper in it. It does not need to be perfectly clean.
The most important thing to pay attention to is the number and letter code on the plastic. This refers to the type of plastic that the product is made out of. The number will be from 1 to 7. Generally speaking, lower number plastics are more likely to be recycled.[8]
Most curbside recycling programs will accept codes 1 (Polyethylene terephthalate, or PET/PETE), 2 (high density polyethylene, or HDPE), and 5 (Polypropylene, or PP).[9]
Plastic number 3 (Vinyl, or PVC) is not generally collected in curbside bins but you can usually find someone who will recycle this material.[10]
Plastic number 4 (low-density polyethylene, or LDPE) is not usually recyclable in curbside bins. Nor is plastic number 6 (Styrofoam).[11] This is because these are not very valuable plastics so it is usually not profitable to recycle these materials, though they are recyclable.
Plastic number 7 is mixed plastic and it is often not recyclable.[12]
Bioplastics: Bio-based, Biodegradable, Compostable, and Oxo-degradable
Bio-based Plastics
There are a lot of materials called bioplastics that are not biodegradable. They are bio-based (made from plants) but are not biodegradable, because biodegradability depends on the chemical structure and not the source.[13]
Bioplastics contribute less than 1% to overall plastics production, though the market is growing.[14] More than half of the bioplastics on the market are just bio-based, not biodegradable.[15]
The bioplastics market is dominated by “drop in materials” like bio-based polyethylene or bio-based PET, which are more or less equivalent to their fossil-based counterparts.[16] They are made from bio-based sources, like sugarcane or corn, but are chemically identical to conventional plastics.[17] The advantage is that these bio-based plastics can be “dropped in” to existing production or recycling infrastructure – you don’t need new machines to deal with them.[18]
There is some advantage to bio-based plastics from a climate change perspective, because they are made from renewable, plant-based resources they require less emissions to produce.
However, because bio-based plastics are not biodegradable, these do not solve the pollution or microplastics problems.
They also do not solve the emissions problem (though they are less emitting than petroleum plastics) because they still release stored carbon when they are incinerated – or if they are landfilled, they may be trapped for a time but release methane later.
And bio-based plastics can cause other problems, since it requires the conversion of land – which can either be wildland or might mean you’re growing food for plastics instead of food crops.[19] There are also the biodiversity, pesticide, and water use issues that have been raised in regard to bio-based plastics.[20] One possible solution is using waste materials or algae as a feedstock for bio-based plastics.[21]
Biodegradable Plastics
On the other hand, there are biodegradable plastics that are not bio-based.
Biodegradable plastics are a good idea, but they are difficult to make.[22] It’s difficult because chemists need to design a plastic that will fulfil all of the desired functions during its use as a product, while also ensuring that it will act as food for microorganisms.[23]
You need the plastics to not just break down (degrade) – they also need to biodegrade, otherwise you’re just creating more microplastics.[24] Organisms need to be able to completely break down the long molecule chains that make up plastics.[25] Which means we need the right microbe with the right enzyme for the right plastic.[26]
There are many types of biodegradable plastics, which can behave in different ways in different places.[27] Biodegradable plastics can take years to break down in the environment.
There are voluntary standards out there for certifying biodegradable plastics, but these usually make reference to biodegradation in specific conditions, like industrial composting. There aren’t yet biodegradability standards for the marine environment, which is not as ideal for biodegradation (it is cold, there is not a lot of sunlight, and there oftentimes is not a high concentration of microorganisms).[28] Since a lot of plastics end up in the oceans, this is maybe something we need to take into account. But this might be impossible as there is a lot of variety in ocean conditions, including different microorganisms – and recall that you need a match between the microorganism and the plastic.[29] But in the wrong situation, it may never break down.[30] So, we can never say for sure if any material biodegrades in the environment – it all depends on where it ends up. And even if it does eventually biodegrade, plastics in the ocean still pose a problem for marine life.
Compostable Plastics
Not all biodegradable plastics are compostable. But some are. So, what about compostable plastics?
Compostable plastic is bio-based plastic that will biodegrade in industrial composting. Compostable plastics cannot be composted in your home compost. And in some cases, it may not be accepted at commercial composting facilities. Check to make sure it’s accepted in your area’s green bin.
For example, it looks like Ottawa does not compost compostable plastic bags. It does accept plastic bags in compost, but that’s because they can sort and remove plastic bags. But ultimately if you put your compost in a compostable bag, it’ll get landfilled along with conventional plastic bags.
Some commercial facilities will compost their compostable plastic utensils and containers, but this is relatively rare. So, even though compostable plastics are a step forward, they usually end up in landfill anyway. Which means they generate methane.
Oxo-degradable Plastics
There is also something called oxo-plastics or oxo-degradable plastics. Oxo-degradable bags are made of conventional plastics, mixed with metal compounds that make them fall apart faster.[31] But it hasn’t been proven that oxo-degradable plastics biodegrade.[32] They might just degrade – meaning that it’s just producing more microplastics for us to eat, drink, and breathe.
So, Are Bioplastics a Solution?
To sum up: bioplastics are a tiny portion of the overall plastics market. Half of bioplastics are just bio-based, not biodegradable. And even if the plastic is biodegradable, it might only biodegrade in certain environments – and we don’t have good systems for ensuring the plastic you’re using will end up in the right place. Compostable plastics, when put in the compost, can be a partial solution.
But generally: bioplastics are not a solution to plastic pollution. To solve that issue you need to address our consumption and disposal of single-use plastics and short-lived plastic products. Instead, we need to reduce plastics – especially single-use plastics – wherever we can. The Plastic-free July website has some useful tips for getting started and next steps once you’ve done the basics. And we need to improve our recycling systems so that plastic actually gets recycled.
Take Action
In our interview with Sarah King of Greenpeace Canada, Sarah asked listeners to sign onto a petition calling for the Government of Canada to implement a strong single-use plastics ban. You can find that petition here.
This week, Kristen also recommends Plastisphere podcast!
Endnotes
[1]50 Things that Made the Modern World Podcast. (2017). Plastic. BBC World Service.
[2] 50 Things that Made the Modern World Podcast, “Plastic.”
[3] 50 Things that Made the Modern World Podcast, “Plastic.”
[4] 50 Things that Made the Modern World Podcast, “Plastic.”
[5] 50 Things that Made the Modern World Podcast, “Plastic.”
[6] 50 Things that Made the Modern World Podcast, “Plastic.”
[7] 50 Things that Made the Modern World Podcast, “Plastic.”
[8] Kellogg, Kathryn. (2019). 101 Ways to Go Zero Waste. New York: Countryman Press.
[9] Kellogg, Kathryn, 101 Ways to Go Zero Waste.
[10] Kellogg, Kathryn, 101 Ways to Go Zero Waste.
[11] Kellogg, Kathryn, 101 Ways to Go Zero Waste.
[12] Kellogg, Kathryn, 101 Ways to Go Zero Waste.
[13] Plastisphere Podcast, “Confused about Bioplastics?”.
[14] Plastisphere, “Confused about Bioplastics?”.
[15] Plastisphere, “Confused about Bioplastics?”.
[16] Plastisphere, “Confused about Bioplastics?”.
[17] Plastisphere, “Confused about Bioplastics?”.
[18] Plastisphere, “Confused about Bioplastics?”.
[19] Plastisphere, “Confused about Bioplastics?”.
[20] Plastisphere, “Confused about Bioplastics?”.
[21] Plastisphere, “Confused about Bioplastics?”.
[22] Plastisphere, “Confused about Bioplastics?”.
[23] Plastisphere, “Confused about Bioplastics?”.
[24] Plastisphere, “Confused about Bioplastics?”.
[25] Plastisphere, “Confused about Bioplastics?”.
[26] Plastisphere, “Confused about Bioplastics?”.
[27] Plastisphere, “Confused about Bioplastics?”.
[28] Plastisphere, “Confused about Bioplastics?”.
[29] Plastisphere, “Confused about Bioplastics?”.
[30] Plastisphere, “Confused about Bioplastics?”.
[31] Plastisphere, “Confused about Bioplastics?”.
[32] Plastisphere, “Confused about Bioplastics?”.