What is plastic?

Plastics are essential in modern society, used in everything from food packaging to hospital hygiene and telecommunications. Biodegradable, bio-based, and recycled plastics offer new alternatives, but the best way to reduce the harm caused by all plastics is to avoid unnecessary consumption.

There are thousands—if not tens of thousands—of types of plastics worldwide. All plastics are made of polymer molecules, to which various additives and fillers are added. Jenni Syvänne, project manager at Muovipoli (a Finnish plastics development organization), considers plastics indispensable to modern society because no other material currently offers the same set of properties.

“Plastics are lightweight, durable, affordable, easy to shape, and hygienic. That’s why they are excellent materials for protecting food, for example, from spoiling.”

In addition to their material properties, plastics help reduce food waste—meaning the loss of edible food. According to Syvänne, cucumbers are often wrapped in plastic because it extends their shelf life many times over.

“This way, the resources used in food production are better utilized.”

Plastics are also widely used in construction (e.g., district heating and water pipes), healthcare, and consumer electronics—from computers to mobile phones.

Plastics are effective in protecting food from spoilage, which helps reduce food waste.”
– Jenni Syvänne, Muovipoli

Different sources of plastics

Plastics can be categorized by use, structure, or origin. They may be made from fossil-based raw materials like crude oil and natural gas, or from renewable, bio-based sources.

“These include, for example, corn, sugarcane, cellulose, and tall oil,” Syvänne explains.

Fossil-based PET plastic and bio-based Bio-PET have the same chemical structure and properties, but Bio-PET is partly made from bio-based raw materials, such as sugars. There are also fully bio-based plastics.

“One of the best-known is PLA (polylactide), used in food packaging, disposable dishes, 3D printing, and medical capsules.”

By structure, plastics are divided into thermosets and thermoplastics. Thermosets have a cross-linked cellular structure that cannot be reshaped after production. Thermoplastics, on the other hand, can be reshaped and recycled into new products with heat and pressure.

By usage, plastics are divided into commodity plastics, engineering plastics, and specialty plastics. The most familiar commodity plastic is polyethylene (PE), used for consumer goods like buckets, freezer containers, and shopping bags.

“Polyamide (PA) is a typical engineering plastic suitable for demanding applications, such as electronic parts or hospital instruments that must withstand heat and impact,” Syvänne explains.

Specialty plastics are used in the most demanding applications. For example, connectors for pipes are often made of PPSU (polyphenylsulfone), which can endure high pressure and temperature.

Plastics can be classified according to their origin, structure, and intended use.”
– Jenni Syvänne

Few biodegradable plastics decompose in Finnish nature

Bioplastics (you are switching to another service)can mean either bio-based plastics made from renewable raw materials or biodegradable plastics designed to break down into biomass, carbon dioxide, and water. Decomposition time varies greatly depending on the environment: in industrial composting, it may take days, while in soil, lakes, or the ocean, it may take months or even years.

Standards define what counts as a “reasonable” decomposition time, but consumers often don’t know how quickly a given product will decompose or how it should be recycled at home. Importantly, biodegradable plastics should never be littered in nature.

“Most biodegradable plastics don’t break down quickly enough in Finnish nature, because freezing winters, the pH value of the soil and many other factors slow down the process. Our roadsides would fill up with plastic waste if people thought it was acceptable to throw biodegradable packaging into the environment.”

A large proportion of biodegradable products do not break down quickly enough in Finnish conditions.”
– Jenni Syvänne

Only about 10% of plastics are recycled

Worldwide, about one million tons of bio-based and biodegradable plastics are produced annually—just 0.4% of all plastics. Plastics made from renewable raw materials account for 1–2% of production, and less than half of those (40–45%) are biodegradable or compostable. Plastics made from recycled materials account for 9–10%.

However, the trend is upward. According to Plastics Europe(you are switching to another service)‘s scenario work, in 2050 the share of bio-based plastics could be close to 17 percent and recycled plastics around 65 percent, of all plastics.

“It’s easier to recycle existing plastics than to increase the share of bio-based raw materials,” Syvänne notes.

Recent innovations, like carbon capture and utilization plastics (CCU), aren’t yet visible in statistics. These plastics are manufactured in processes that bind carbon, thereby reducing greenhouse gas emissions.

“At best, such plastics act as carbon sinks—but only if the products are long-lasting, and the captured CO₂ comes from industrial processes, like energy production or waste incineration, where it would otherwise be released into the atmosphere.”

New plastics don’t solve every challenge

While bio-based plastics reduce fossil fuel use and CO₂ emissions, they are not problem-free. Issues like single-use culture and littering also apply to new plastics.

“Plastics’ greatest strength—durability—becomes a problem when they are carelessly discarded or when waste management is inadequate,” Syvänne summarizes.

New plastics raise further concerns, such as whether limited farmland should be used for growing food crops or raw materials for plastics.

“Bio-based plastics may compete with food production, raising questions about irrigation water use and fertilizer runoff that can pollute waterways.”

So far, no replacement has been found for fossil-based plastics that would solve all the problems. With new materials, one must always weigh resource consumption against benefits.

“The balance includes technical properties, environmental emissions, product safety, and economic effects. Plastics also provide global employment and livelihoods. If we stopped using plastics entirely right now, many sectors—like healthcare and telecommunications—would suffer serious setbacks.”

Responsible use and recycling are key

According to Syvänne, both new and traditional plastics must be chosen carefully for each application to ensure durability and sustainable resource use.

“Even more important is reducing unnecessary consumption of all materials, which is a broader societal issue than plastics alone. Unnecessary consumption includes, for example, excessive packaging without a valid reason, or products that cannot be repaired.”

Plastics-related problems cannot be solved with one or two changes—structural changes to society are needed. Recycling is part of this transition. The EU’s waste directive aims to raise plastic packaging recycling rates (26.9% in 2024) to 50% by 2025.

“This requires better sorting of plastic packaging and the introduction of chemical recycling alongside mechanical recycling. Mechanical recycling involves sorting, crushing, and melting plastics, while chemical recycling breaks plastics back into raw components to make new plastics.”

Legislation is essential to drive change. It can regulate health impacts of plastics(you are switching to another service), influence consumer behavior (e.g., banning single-use items like plastic straws), and require companies to design long-lasting, resource-efficient products.

Ultimately, the issue comes down to human values. In Finland, waste management is strong, but in many countries, plastics still end up in illegal dumps, nature, waterways, and eventually the oceans.

“That’s why plastics are always a global issue, with the most severe consequences seen in the daily lives of the world’s poorest people.”

Consumers need reliable, easy-to-understand information to make sustainable choices.

“People should be encouraged to avoid unnecessary single-use products and to choose durable, reusable alternatives—not only in plastics, but in all consumption.”

According to Jenni Syvänne, a Master of Science in Materials Engineering, plastics are essential to society, but their use should be sustainable in terms of natural resources.

More information

Jenni Syvänne

Project manager, Muovipoli Oy; PlastLIFE project partner

firstname.lastname@muovipoli.fi