What are eco-friendly plastics?

Important Insights

Every year, U.S. landfills process tens of billions of tons of plastic [source: ACF]. But in reality, "process" means "leave it alone" -- the plastic remains intact for centuries. The microorganisms that decompose other waste refuse to break down plastic.

The environmental crisis of plastic-filled landfills has sparked a shift from plastic to paper grocery bags, using cardboard for prepared foods instead of plastic, and even incorporating "eco-plastic" components into products like the Toyota Raum, a car exclusive to Japan. [source: SLM].

Eco-plastics may seem like an unlikely concept, perhaps even contradictory, but they could be the next important step in making our world greener.

Eco-plastics come in various forms. Some are made entirely or partially from recycled conventional plastics. These traditional, petroleum-based plastics typically remain in landfills for centuries. While these "eco-plastics" aren't more biodegradable than their non-recycled counterparts, they have the advantage of reducing the amount of nonbiodegradable waste that ends up in landfills.

However, when we talk about environmentally friendly plastic, we're often referring to "bioplastics," which are quite different. Bioplastics are made from renewable biological materials rather than fossil fuels, and they offer distinct properties compared to traditional plastics. There’s also a newer category of plastics made from synthetic materials that may behave differently in landfills than conventional plastics.

In this article, we’ll explore what eco-plastics truly are, how they’re used, and whether they can help or hinder environmental efforts.

To grasp the concept of eco-plastics, it's important to first look at the objectives behind their creation. Except for the recycled traditional plastic version, eco-plastics should primarily break down naturally in typical landfill environments. But the real question is – can this even be achieved?

Eco-Plastic Types

For years, we've recognized plastic as an environmental villain. It's derived from fossil fuels, consumes immense energy during production, and fills landfills indefinitely. It's hard to imagine purchasing a plastic product without feeling guilty. Whether eco-plastics can alleviate that guilt depends on how environmentally conscious one is.

Eco-plastics come in various types: recycled petroleum-based plastics, bio-based (plant-derived) plastics, and other miscellaneous types. Each type offers distinct eco-friendly attributes.

Recycled traditional plastic consists of different amounts of "virgin" plastic, which is non-recycled, conventional plastic. The environmental appeal here is that all this unused plastic is repurposed to create items like lawn furniture, rather than being discarded into a landfill. However, it’s important to note that this material is no more biodegradable than its original form.

Bioplastics, derived from plant materials, are designed to decompose fairly quickly in landfills and even in some compost bins. The most popular types include starch-based plastics like polyactide (PLA), commonly used for biodegradable food trays and disposable cups. Another example is polyhydroxyalkanoate (PHA), which is made from starches like corn, sugarcane, or beetroot and is typically found in cosmetic bottles. Plastics made from cellulose, the primary component of plant tissue, are also considered bioplastics, as are those derived from soy protein or lactic acid.

There are also several recent innovations in plastics that fall into the "miscellaneous" category. ECM Biofilms has developed a process where they incorporate microbe-attracting pellets during production, making traditional plastics break down more rapidly in landfills. Additionally, Novomer is working on biodegradable plastic made from carbon dioxide and carbon monoxide combined with liquid metal, which offers the benefit of both biodegradability and the potential to remove harmful gases from the air.

While all these eco-friendly plastics offer environmental benefits compared to conventional plastics, the real challenge lies in translating theory into practice. The idea is that these plastics are biodegradable, but because they are still relatively new in industrial terms, long-term research and data are somewhat limited.

Can Plastics Go Green?

Up until now, the bulk of research surrounding the biodegradability of eco-friendly plastics has focused on bioplastics, particularly PLA, the most prevalent type made from starch. Here’s what we know so far:

PLA is biodegradable, but it’s not an easy or quick process [source: Teschler]. The exact time it takes to decompose under landfill conditions remains unclear. It’s expected to break down once discarded, but it’s uncertain whether it’ll happen swiftly or over a long period. Studies on its decomposition in compost bins suggest that it may take anywhere from three months to a year, while others indicate that only commercial composting systems can handle it, not home compost setups [sources: Worldcentric, Teschler].

What’s clear is that until PLA breaks down, it occupies as much space as conventional petroleum-based plastics. Bioplastic containers usually contain just as much material as their plastic counterparts.

In addition to the volume of waste and the biodegradability factor, another critical issue with eco-plastics is the energy required to produce them. Is it more energy-efficient to manufacture "green" plastic containers compared to petroleum-based ones? There’s still no clear answer. Some argue that the energy needed is about the same, since shaping starch-based materials into cups requires just as much effort as forming fossil-fuel-based plastics into cups [source: Teschler]. However, it’s important to note that companies in the eco-plastic sector are more likely to adopt alternative or low-energy production methods, as their target market is environmentally conscious. For example, Ingeo, a bioplastics company, has introduced new manufacturing processes that reduce its greenhouse gas emissions by 60% and its overall energy usage by 30% [source: GD]. According to Ingeo, producing its bioplastic now results in 77% less CO₂ emissions than making conventional petroleum-based plastic.

One of the key environmental drawbacks of bioplastics is the use of agricultural land. The cultivation of corn, sugarcane, or beets requires significant farmland that could otherwise be used for food crops or ethanol production. However, if we must continue using plastics, the trade-off might be worthwhile. For instance, when the food company ConAgra transitioned from petroleum-based plastics to PLA plastic for the shrink wrap on products like Parkay and Fleishmann's margarine, it claimed to reduce its CO₂ emissions by half a million pounds [source: GD]. Now, imagine if they also started making their tubs from bioplastics.