Plastic has many uses because of its ability to be moulded, pressed, and extruded into almost any solid shape. The durability and low-cost production of plastic have also contributed to its universality. Plastics are durable against natural forces such as erosion and corrosion, disproportionately strong compared to their weight, and highly insulating against thermal, electric, and acoustic energy.
Plastic production includes synthetic polymers, synthetic fibres, additives, primary plastics, and synthetic resins. These are defined as:
Plastics are defined by their size, with macroplastics being larger than 5 mm and microplastics being smaller than or equal to 5 mm. Macroplastics include items like plastic bags and plastic straws, while microplastics include things like microfibres from clothes and microbeads from facial cleansers. Microplastics are also formed when macroplastics break down.
Primary vs. Secondary Microplastic Definitions
The following table summarises the 7 resin identification codes (RIC) that can be found on most plastic items. This table gives descriptions of each type, examples of common items of each RIC, how much of each RIC is newly produced, and the ease of recyclability for each RIC.
| Resin Identification Code (RIC) | Polymer Acronyms | Polymer Names | Common Items | Primary Production, https://ourworldindata.org/grapher/plastic-production-polymer | Description | Recyclability |
|---|---|---|---|---|---|---|
| 1 | http://www.petresin.org/news_introtoPET.asp | Polyethylene terephthalate | Water Bottles, food jars, salad dressing containers, mouthwash bottles, tote bags, polyester fibres, furniture, carpet, containers | 33 million tonnes | Most PET items are meant for single use. Cleaning these items with cleaning products can create carcinogens, making reusing them hazardous for humans. Heating up PET items can also release harmful chemicals. | Easily recyclable and accepted by almost all recycling plants. When recycled, PET items are shredded and turned into more PET items. |
| 2 | https://www.acmeplastics.com/what-is-hdpe | High-density polyethylene | Cleaning product bottles, snowboards, cutting boards, milk jugs, bottle crates, ropes, plastic lumber, playground equipment | 52 million tonnes | HDPE items are incredibly sturdy and have a high impact resistance. They can also withstand heating and cooling, making them safer and more versatile than PET items. | Easily recycled up to 10 times. Clear HDPE items are recycled into the same new items. Coloured HDPE items are made into other items like toys, pipes, and pens. |
| 3 | https://www.chemicalsafetyfacts.org/polyvinyl-chloride/ | Polyvinyl chloride | Pipes, fencing, flooring, lawn chairs, saran wrap, shower curtains, window profile, children’s toys, IV bags, medical tubing, medication bottles | 38 million tonnes | PVC items are strong and elastic due to softening chemicals added. PVC items can be incredibly toxic for humans if heated or corroded. | Cannot be recycled because of chemical additives. On the rare occasion when PVC is recycled, they are made into lower-quality products like traffic cones, binders, and cables. |
| 4 | https://sciencing.com/difference-epe-foam-eva-foam-8736270.html | Low-density polyethylene | Plastic bags, six-pack rings, containers, dispensing bottles, wash bottles, plastic wrap, bread wrapping, trays | 64 million tonnes | LDPE items have higher elasticity. LDPE items are more resilient than PET items and can be reused. | Can sometimes be recycled depending on the item. Many of these items should be reused before being thrown out. |
| 5 | https://www.creativemechanisms.com/blog/all-about-polypropylene-pp-plastic | Polypropylene | Auto parts, industrial fibres, yoghurt and sour cream containers, straws rope, bottle caps, carpet, containers, dish-ware | 68 million tonnes | It is not safe for humans when PP items are heated but they can physically withstand being heated. | Can sometimes be recycled. Should be reused if possible because they are taken in by recycling facilities at very low rates. |
| 6 | https://www.chemicalsafetyfacts.org/polystyrene/ | Polystyrene | Food packaging, laboratory ware, appliances, plastic utensils, electronics, toys, gardening pots, surfboards, egg cartons, CD cases, disposable drinking cups, child car seats, appliance insulation, styrofoam | 25 million tonnes | Breaks up very easily making it a large polluter. PS items are often found on beaches and cause issues to marine creatures. | PS items are often not recycled as they are too lightweight to be recycled. They are instead incinerated. |
| 7 | https://millerrecycling.com/plastics-recycling-numbers/ | Other | Headlight lenses, safety shields and glasses, sports bottles, baby bottles, medical and dental equipment, lids, legos | 111 million tonnes | Other plastics, such as acrylic, nylon, polycarbonate, acrylonitrile butadiene styrene, and other combination plastics. | Can sometimes be recycled depending on the item. Acrylic plastics cannot be recycled, nylon is very difficult to recycle, and polycarbonates are easy to recycle. |
<aside> 🥚 Plastic toy dinosaurs are primarily made up of polyethylene, RIC 2, one of the main plastics that were mass-produced during WW2 for war-related products and goods. The same plastic that is used to make plastic toy dinosaurs was once a military secret, used almost solely for insulating cables on military radar devices.
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