materials – Chasing Tales

“Plastic” is the generic name of a large group of materials. Conventional plastics are made from fossil fuels, however there are now an increasing number of bioplastics available. This post will be about fossil plastics.

Plastics are organic polymers- this means that while other molecules may be added to their chemical composition if required (to create different properties), they are always composed of hydrogen and oxygen molecules.¹ Polymers are large chain-like molecules formed of smaller molecules called monomers², which may be natural or synthetic, and their chief quality of interest is that they can link together to form polymers.³ Polymers can be formed of between two and seven monomer units.³

The first synthetic plastic was invented in 1907 and called Bakelite.⁴ Since then, it is estimated that 8.3–9.2 billion metric tons of plastic were produced between 1950 and 2017, with over 400 million metric tons being produced annually in recent years.⁵

The Good

These enormous production numbers are because plastics are a highly versatile group of materials, and are used in every industry due to their properties- they are easy to mould, can be strong or flexible as required, are both electrical and thermal insulators, lightweight, durable, chemically stable and many are corrosion resistant. Their invention has been a boon to humanity in a variety of ways, an example of which is their usage in the medical industry, which has revolutionised medicine and allowed it to be accessible to many more people- from basic gloves, to prosthetics, to blood bags, plastics are ubiquitous in medicine and pharmaceuticals.⁶

Yet the medical industry is ultimately a minuscule consumer of plastic. 436.66 million tonnes (Mt) of plastics were traded in 2022, with final products alone accounting for 111 Mt.⁷ The vast majority (between 31% and 40%) of plastics are used today to package products, followed by the construction industry at ~17%, the automotive sector accounts for ~9-18% of global plastic, followed by household and consumer products which take up ~13% of the plastic produced, and electrical and electronic products with ~9%. The residual plastic, which comes to less than 10% of the total production, is used in a variety of sectors, including medical equipment, road signs, etc.⁷^{8 9}

S. No.	Name	You’ve Used This In
1	Polyethylene (PE or LDPE)¹⁰	Plastic bags, cling film for food storage, extrusion coatings, insulation for wires, etc.
	Medium-Density Polyethylene (MDPE)¹¹ ¹²	Shrink wraps, storage tanks, road blocks, traffic cones, fuel tanks, etc.
2	High-density polyethylene (HDPE)¹⁰	Pipes, construction material, insulation, plastic bottles, containers, containers for chemical preparations like shampoos and medical supplies, toys, geomembranes, fuel tanks, and swimming pool equipment are some uses.
3	Linear Low-Density Polyethylene (LLDPE)¹³	Shopping bags, dustbin liners, bubble wrap, stretch and, shrink wrap, plant pots, pipes and tubing, fluid reservoirs, automotive consoles, toys, kayaks, paddleboards, detergent containers, etc.
4	Ultra-High Molecular Weight Polyethylene (UHMWPE)¹⁰	Pipes, valves, bulletproof material, aircraft and spacecraft components, battery separators, sail cloths, helmets, Conveyor belts, etc.
5	Polypropylene (PP)^{15 16}	Food containers, bottles, plastic bags, car parts such as dashboards or bumpers, disposable syringes, surgical tools, non woven fabrics, fibre and textiles, battery cases, wire insulation, pipes, roofing material, outdoor furniture, etc.
6	Polyvinyl Chloride (PVC)¹⁷	Pipes, credit cards, IV bags, windows, clamshell and other types of packaging, rain wear, shower curtains, etc.
7	Polystyrene (PS)¹⁸	Disposable cutlery, construction material, seat cushions in cars, automotive door panels, CD cases, foam cups, shock lining in helmets, packaging, insulation material, diagnostic tools, laboratory apparatus, and other uses.
8	Polyethylene Terephthalate (PET)^{19 20}	Beverage bottles, food backaging, clothing and textile, other packaging, disposable cups, photovoltaic parts, gear housing, greenhouses, and other applications.
9	Acrylonitrile Butadiene Styrene (ABS)²⁰	There are more than 6,000 grades of ABS produced today. LEGO bricks, hutomotive parts, household appliances, consumer goods, walking sticks, 3D printing, medical devices, pipes and fittings, sports equipment, etc.
10	Polyurethane (PU)^{21 22}	Automotive components such as dashboards, mud flaps, car door panels, etc., footwear, medical materials, insulation, paint, coatings, aerospace components, agricultural products, cutting sticks, gaskets, Diablo rollers, manufacturing industries, mining, quarrying, oil and gas sectors, and other uses.
11	Polycarbonate (PC)²³	Coffee machines, food processors, automotive headlamp bezel and lenses, hair driers, construction material, surgical instruments, blood reservoirs, protect eye gears, etc.
12	Polylactic Acid (PLA)²⁴	This polymer is biodegradable, and degrates into lactic acid. Used in medical implants, food packaging, engineering plastics, drink packaging, disposable cutlery, shrink wrap, 3D printing.
13	Polyethylene Terephthalate Glycol (PETG)²⁵	3D printing filament, Consumer electronics, automotive parts, construction material, art and other customised products, etc.
14	Nylon²⁶	Ropes, automotive parts, workout wear, swimwear, rain protective wear, guitar strings, nets, and many other uses.
15	Ethylene-vinyl acetate (EVA)^{27 28}	Shoe soles, foam mats, adhesives, protective padding, solar panels, automotive interiors components like mats and cushions, sports equipment, toys, etc.
16	Thermoplastic polyurethane (TPU)²⁹	Automotive parts, animal identification tags, textile coatings, garments, adhesives, military equipment, conveyor belts, seals, and other uses.

A few commonly used plastics

The global demand for plastics has quadrupled over the past decades⁷ and the OECD suggests that under the business-as-usual scenario it is projected to triple by 2060, and of this only 12% is likely to be secondary, or recycled plastic.³⁰ The entire plastics market was valued at $712 billion in 2023 and is projected to continue growing, and thus supports millions of jobs at the moment: As of 2023, the U.S. plastics industry directly employed over 1 million people in the United States, with total plastics-related jobs (such as sales, etc. in the U.S. reaching up to 1.55 million.³¹ In India, the plastics industry comprises over 50,000 processors and employs over 5 million people directly and indirectly³². It’s also good to remember that the industry does not only consist of direct plastics manufacturing and usage, but has also made several other activities possible in other industries which would not otherwise have been possible (the example of the medical industry is discussed above), thus also adding to jobs in those sectors. In totality, it is approximated that there were 7,637,284 people employed in just the Global Plastic Product & Packaging Manufacturing as of 2024.³³

The Bad

On the flip side, this gargantuan human appetite for plastics has caused a macro and micro plastic buildup in the planet.³⁴ According to the United Nations, 51 trillion microplastic particles – 500 times more than stars in our galaxy – litter the seas. They go on to say that by 2050, oceans will have more plastic than fish 99% of seabirds alive will consume microplastic if ongoing trends of plastic pollution are not abated³⁵– and microplastics are now increasingly being found inside humans as well.^{36 37}

Plastics are now in our seafood, the air we breathe³⁸, our tap water³⁸, and even in our fetuses³⁷. In fact, a study approximates that the average adult consumes approximately 2,000 microplastics per year simply by consuming salt. But plastics being found in our systems are a new phenomenon, and therefore are poorly studied. We don’t yet know even the short term impacts of being made up, to a small extent, of our plastic- except they may just be contributing to preterm births³⁷, and hundreds of thousands of annual heart disease deaths³⁹. The OECD has stated that plastic leakage to the environment is likely to double to 44 million tonnes (Mt) annually, while the build-up of plastics in aquatic environments will more than triple, and greenhouse gas emissions from the plastics lifecycle will more than double, from 1.8 gigatonnes of carbon dioxide equivalent (Gt CO₂e) to 4.3 Gt CO₂e further aggravating environmental and human toxicity.³⁰

In 2022, only 2% of plastics produced were made from renewable sources- of the remaining 98%, 44% was derived from coal, 40% from petroleum, 8% from natural gas, 5% from coke and 1% from other sources.⁷ In 2019, plastic production amounted to 5.3% of total greenhouse gas (GHG) emissions that year, or ~2.24 billion mt of carbon dioxide equivalent. Of this, extracting feedstock fossil fuels used accounted for 20% of the 2.24 billion mt, creating monomers for 26%, and refining hydrocarbons and producing other plastic ingredients kick out 29%.^{40 41} This spotlights the first of plastic’s environmental issues- even though plastics result in lower greenhouse gas emissions throughout their life cycle compared to alternative materials like metals or glass⁷, as long as they are extracted from mineral fuels, they will continue to have an outsized impact on the planet, because most of their GHG emissions are produced not during their lifecycle as plastics, but well before they come into existence, at the extraction, monomerisation, and refining stages. Upto 70% of the fossil fuel used in plastic creation comes from the raw materials used in production, and not the electricity used in processing them.⁴² Another way to look at this is that in a 2018 study it was determined that recycled PET, recycled HDPE, and recycled PP consume 79%, 88%, and 88% less total energy respectively than producing virgin PET, HDPE, and PP⁴³– So while plastics live a virtuous life, the physical and chemical processes during their conception, birth, and post mortem are traumatic for our planet and all living beings on it.

In 2024, humans were projected to have generated 220 million tonnes of plastic waste, an increase of 7.11% from 2021.⁴⁴ in the same year, Greyparrot.ai, detected 40 billion waste objects at 55 facilities across 20 countries in North America, Europe and Asia. They tracked over 35,000 tonnes of recyclable plastics which were not recycled, and also detected clear plastic containers (like thermoform packaging), and over 7 billion flexible film objects.⁴⁵ The Alliance to End Plastic Waste estimated in 2023 that at least 360 million tonnes of plastic waste are generated annually, and of that 70% remains uncollected, or was improperly disposed off, leading to leaks into the environment, landfill dumping, open burning.⁴⁶ Researchers have estimated that ~34% of global plastic waste is incinerated, which is emerging as the most practiced method for disposal.⁷ About 40% of plastic waste is still fed to landfills (a method of disposal found to be shrinking), and only 9% is recycled.⁷

Incineration is simply the burning of waste matter, also known as Waste-to-energy (WTE), Thermal treatment, Energy-from-waste, or Energy recovery. When burnt, plastic remembers its fossil origins and generates high temperatures. The combustion is often open, without any way to capture the toxins released.⁴⁷ Without plastic as part of municipal waste, municipal waste management systems have been known to add coal⁴⁸ to the waste mix to help achieve the kind of temperatures plastic waste achieves when set fire to⁴⁹. Thus, firstly, municipal waste management plants have an incentive to encourage plastic waste (so they don’t spend on fuel/ they spend less on fuel). Waste incineration is also known to produce carbon dioxide, carbon monoxide, hydrogen chloride, sulfur oxides, nitrogen oxides, metal oxides, and metal vapours, fly ash, bottom ash, dioxins, polychlorinated biphenyls, and black carbon.⁴⁷ ⁴⁸ Contaminants also get into the soil and groundwater and frequently contain additives (such as fillers, plasticizers, flame retardants, colorants, stabilizers, lubricants, foaming agents, antistatic agents, and metals, including cadmium, chromium, lead, mercury, cobalt, tin, and zinc), in addition to adhesives and coatings.⁴⁷ In 2019 CIEL estimated that just burning plastic packaging in the open releases 2.9 Mt CO2e of greenhouse gases into air per ton of plastic packaging⁵⁰. Further, the open burning of plastics is associated with an increased risk of heart disease, respiratory issues, neurological disorders, nausea, skin rashes, numbness or tingling in the fingers, headaches, memory loss, confusion, cancer and birth defects.⁴⁷

The second method of plastic disposal mentioned are landfills. A landfill is an ecological system, where the inputs are solid waste and water, and the outputs are leachate (The liquid produced when water percolates through any permeable material) and gas produced by the joint action of biological, chemical, and physical processes. Leachate Recycling landfills are designed to capture and recycle aqueous leachate to prevent or reduce the environmental leakage of potentially harmful waste or degradation residues. Controlled Contaminant Release landfills allow the leachate to migrate to the environment under monitored conditions to prevent harmful events. Unrestricted Contaminant Release landfills, which are older waste dumps, have no controls on leachate or environmental contamination.⁵¹ There is no method of knowing what is ultimately happening inside landfills, however, due to the fluctuating temperatures (reaching as high as 60 to 90 °C) and pH (4.5–9), deep-seated fires, physical stress, and compaction, as well as limited microbial activity, landfilled microplastics are likely to continue to fragment into nanoplastics. While most polymers and plastics remain unchanged in landfills, some may degrade into further fragments or biodegrade to water and either are carbon dioxide in aerobic environments or a mixture of carbon dioxide, methane, and volatile organic compounds (VOCs) in an anaerobic environment.⁵¹

This brings us to our third plastic problem- plastic exists everywhere, including places it shouldn’t be in. Plastic litter is categorised as macroplastics (those bits of plastic detritus which are larger than 5 mm), microplastics (the infamous plastic discard sibling, coming in at <5 mm), and nanoplastics (ultrafine particles <100 nm).⁵² Macroplastics made up 88% of the global plastic waste in 2019, tallying up to ~20 million metric tons in that year. This is the plastic that breaks down into smaller bits due to physical and chemical processes- such as incineration, leaks from landfills, interations with biotic and abiotic forces, etc.⁵² ⁵³

The Solutions

In order of what I think will have the quickest impact/ be the easiest to do:

1. Clean up macro plastic waste, and fine littering.

2. Mandating superior waste sorting, so that recyclable plastics are removed from being incinerator or landfill food. This will require more than just regulation- waste segregators, whether human or AI, will have to be taught how to identify recyclable plastics, which at the moment are PET, HDPE, PP, LDPE, and PVC, with varying levels of ease⁵⁴ ^{55 56} ,and the number of recycling facilities will have to be increased around the world for all kinds of plastics.

3. Ban (or tax) single use plastics, including those that cannot be recycled (in theory all plastics can be recycled).

4. Investment in and policies to encourage biodegradable plastics.

5. Reduce consumption. Of course this will require a cultural shift, and goes against our general capitalist consumerist values, but less consumption leads to less plastic used for making, packaging, transporting, installing, using, and disposing off the product.

6. Have some compassion- plastics have made all our lives better, but especially so for disadvantaged people. This mess was created over a century, so we can take a few years to sort it out without demonising or causing problems to those who need help the most.^{57 58 59 60}

Sources:

Tag: materials

Materials: Plastics

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