What is plastic?

Plastic is a chemical material that became popular because it can be easily adjusted to any shape in the process of production. It is a fully synthetic material that does not require organic materials and can be produced in the chemical lab. The chemicals involved in the creation of plastic are cheap and widespread, so its production is available for most countries.

The History of Plastics

The history of plastics has an underlying story. In 1863, a billiard company Phelan & Collender in New York created a challenge with a reward of $10,000 to find alternative material for the creation of billiard balls. At that time, billiard balls were created of elephant tusks, which were becoming scarce. John Wesley Hyatt, a printing company employee, first invented and patented plastic, the creation of which involved organic material cotton. The Phelan & Collender company did not accept the plastic billiard balls, considering them of cheap quality. However, Hyatt and his brother founded a company that successfully sold plastic billiard balls. The only problem with the balls was that they were easily flammable.



An original celluloid billiard ball made by Hyatt’s company, CH*334572, National Museum of American History. The plaque reads: “Made in 1868 of Cellulose Nitrate, Celluloid. The Year John Wesley Hyatt Discovered This First Plastics Resin.” © Smithsonian Institution


The trials to create a synthetic material continued until Leo Baekeland successfully synthesized a new type of plastic that did not contain organic materials. This event pushed plastic development forward and gave a start to the mass production of plastic. Such production did not depend on the availability of organic elements, which made it cheap and fast. Since the latter two sound like a savior for the suffering economy, plastic production boomed during World War II, when plastics like nylon were massively used in military equipment. After the war, plastics remained to be a cheap alternative to more and more products in many industries. At that moment, questions regarding the recycling of plastics and biodegradability were not discussed.

Seven Categories of Plastics

Today, there are seven categories of plastics grouped by our ability to recycle them. These categories are called "recycling code numbers." We meet plastics from all of these categories at home or when visiting stores.

  1. Polyethylene Terephthalate - this is what water bottles are made of.

  2. High-Density Polyethylene (HDPE) is used for grocery bags, as well as for shampoo bottles and caps.

  3. Polyvinyl Chloride (or Vinyl, or PVC): plastics in this category have many lives. Thick wall bottles and caps can be utilized in the production of pipes or traffic cones.

  4. Low-Density Polyethylene (LDPE) is softer and more flexible than High-Density Polyethylene (HDPE) is used to make squeeze bottles and dry cleaner bags. Also, LDPE is used to make gas and water pipes.

  5. Polypropylene is used in the production of diapers, plastic chairs, and plastic food containers.

  6. Polystyrene: CD cases, foam food containers, egg boxes, disposable plates are made of this plastic.

  7. Others: This category includes all other types of plastics that did not fall under the first six recycling code numbers. It includes such plastics as nylon, which became popular during World War II, and is currently used as a clothing material. Also, this category includes acrylonitrile butadiene styrene (ABS), known as the material for Lego pieces.

All these categories of plastics have different abilities to be recycled. Some, like category #1 or hard forms of #2, are commonly recycled. Other plastics like #3 or #4, are not easy to recycle, but products made from these materials can be reused. Plastics under recycling code #6 are banned in many cities due to the high cost of the recycling process.

Plastic Nurdles

Plastic pellets are used for the production of plastic and are called nurdles. Through melting, nurdles are shaped in any form, such as water bottles. Due to spillage during transportation, a vast amount of them is found in the oceans. Yearly, the beaches of Orange County in California are polluted with 105.2 million nurdles (98% of all debris). A big number of nurdles are also found on Bermuda beaches and the beaches of Massachusetts.


Image from WUSF Public Media:

A clear bag with hurdles is in a palm on a blurry background of sand.

Microplastics

Microplastics, also called microbeads, are tiny particles of plastic, reaching in their size 1 to 5 mm (or 0.04 to 0.2 inches). They account for approximately 90% of all plastic pollution, are nearly invisible, and are incredibly hard to filter out of ocean water. These beads are produced for scrubbing in cleaning and are used in facial exfoliators, toothpaste, and hand wash. The amount of microplastic consisting in a tube may exceed the plastic package itself. Microplastics are created by a process called photodegradation, where the sun breaks plastic down into tiny particles. As large pieces of plastic degrade in nature, they tend to fragment into smaller and smaller particles without substantially reducing in mass. Many non-plastic sources of pollution tend to accumulate on the high surface area of the small plastic particles, so the bioaccumulation of microplastics through the food web brings with it the accumulation of these other toxic chemicals. These particles attract oils and other not dilutable toxic elements, such as DDT and dioxins, which poison marine life. Since 1970, the amount of microplastic in the ocean has exceeded more than 100 times. More than 21,000 metric tons (46 million pounds) of microplastics are approximated to be resting in the Pacific Ocean.

The main contributors to microplastics are:

  • Synthetic Textiles

  • Tires

  • City Dust

  • Road Markings

  • Marine Coatings

  • Personal Care Products

  • Plastic Pellets

Picture from Shark Research. Global Releases of Primary Microplastics to the World Oceans: This diagram shows the main sources of primary microplastic pollution in the world's oceans: Synthetic Textiles 35%, Tires 28%, City Dust 24%, Road Markings 7%, Marine Coatings 3.7%, Personal Care Products 2%, Plastic Pellets 03%.

Biodegradable and Biobased Plastics

The issue with plastic pollution is that plastic takes so long to break down naturally, so it sticks around in ecosystems for decades or even centuries. What if we could design a plastic material that would actually degrade into non-toxic substances relatively quickly when it does get disposed of improperly and ends up in oceans? Truly, that would solve many of the problems of plastic pollution. Biodegradable plastics are plastics designed to break down into safe organic chemicals under special circumstances, but unfortunately, the technology is still in its infancy and many biodegradable plastics fall short of our goal. In fact, biodegradable plastics are currently only able to biodegrade under extremely specific conditions.

One subset of biodegradable plastics is compostable plastics. These plastics are designed to break down into compost in carefully controlled composting environments. It is important not to put these plastics into your home compost pile, as the conditions to compost these plastics are only attainable in specially designed industrial composting equipment. It is also important to not dispose of these plastics in your normal plastic recycling, as the compostable plastic can contaminate the other plastics being recycled.

Biobased plastics are plastics that are made entirely from plants and other renewable resources. It is important to understand that just because plastic is biobased, it is not necessarily biodegradable or compostable. In fact, some biobased plastics can be chemically identical to petroleum-based ones, and just as harmful to the environment.